Diogenes Laertius: The Life of Epicurus

Book X of Diogenes Laertius’ Lives and Opinions of Eminent Philosophers  is the major source for much of what we know about the details of the life of Epicurus.  This work is also the source for our knowledge of Epicurus’ three main letters, his "Wise Man" sayings, and his Principal Doctrines.  Although the text indicates that Laertius was clearly sympathetic to Epicureanism, there is no definite proof that Laertius was an Epicurean himself.  Laertius lived between 200 and 500 AD (probably around 225 AD). A summary of what is known about Laertius’ own life may be found here, and information about the survival of the manuscript of his work is here.   

I have included a full presentation of Book X in the free epub “A Life Worthy of the Gods,” which can be downloaded for free here, and also at Smashwords and at Google books

The text included here was prepared based the translation of C.D. Yonge found in the 1853 Edition of Bohn’s Classical Library.  Copies of the original text are available at Scribd and at Archive.org.




The Life of Epicurus – by Diogenes Laertius

The Will of Epicurus
Epicurus’ Letter to Idomeneus
Epicurus’ Letter to Herodotus
Epicurus’ Letter to Pythocles
The "Wise Man" Sayings
Epicurus’ Letter to Menoeceus
The Principal Doctrines


Epicurus was an Athenian, and the son of Neocles and Chaerestrate, of the deme of Gargettus, and of the family of the Philaidae, as Metrodorus tells us in his treatise on Nobility of Birth. Some writers, and among them Heracleides, in his Abridgment of Sotion, say that as the Athenians had colonized Samos, he was brought up there, and came to Athens in his eighteenth year, while Xenocrates was president of the Academy, and Aristotle at Chalcis. But after the death of Alexander the Macedonian, when the Athenians were driven out of Samos by Perdiccas, Epicurus went to Colophon to his father.

And when he had spent some time there, and collected some disciples, he again returned to Athens, in the year of Anaxicrates, and for some time studied philosophy, mingling with the rest of the philosophers; but subsequently, he somehow or other established the school which was called after his name; and he used to say, that he began to study philosophy when he was fourteen years of age; but Apollodorus the Epicurean, in the first book of his account of the life of Epicurus, says, that he came to the study of philosophy, having conceived a great contempt for the grammarians, because they could not explain to him the statements in Hesiod respecting Chaos.

But Hermippus tells us, that he himself was a teacher of grammar, and that afterwards, having come across the books of Democritus, he applied himself with zeal to philosophy, on which account Timon says of him: –

The last of all the natural philosophers, And the most shameless too, did come from Samos, A grammar teacher, and the most ill-bred And most unmanageable of mankind.

And he had for his companions in his philosophical studies, his three brothers, Neocles, Chaeredemus, and Aristobulus, who were excited by his exhortations, as Philodemus the Epicurean relates in the tenth book of the Classification of Philosophers. He had also a slave, whose name was Inus, as Myronianus tells us in his Similar Historical Chapters.

But Diotimus the Stoic was very hostile to him, and calumniated him in a most bitter manner, publishing fifty obscene letters, and attributing them to Epicurus, and also giving him the credit of the letters, which generally go under the name of Chrysippus.  And Poseidonius the Stoic, and Nicolaus, and Sotion, in the twelfth of these books, which are entitled the Refutations of Diocles, of which there are altogether twenty-four volumes, and Dionysius of Halicarnassus, have also attacked him with great severity; for they say that he used to accompany his mother when she went about the small cottages, performing purification, and that he used to read the formula, and that he used also to keep a school with his father at very low terms. Also, that he, as well as one of his brothers, was a most profligate man in his morals, and that he used to live with Leontium, the courtesan. Moreover, that he claimed the books of Democritus on Atoms, and that of Aristippus on Pleasure, as his own; and that he was not a legitimate citizen; and this last fact is asserted also by Timocrates, and by Herodotus, in his treatises on the Youth of Epicurus.

They also say that he used to flatter Mithras, the steward of Lysimachus, in a disgraceful manner, calling him in his letters Paean, and King; and also that he flattered Idomeneus, and Herodotus, and Timocrates who had revealed all his secret practices, and that he flattered them on this very account. And in his letter to Leontium, he says, “O lord Paean, my dear Leontium, what transports of joy did I feel when I read your charming letter.” And to Themista, the wife of Leonteus, he writes, “I am ready and prepared, if you do not come to me, to roll myself to wherever you and Themista invite me.” And he addresses Pythocles, a beautiful youth, thus, “I will sit quiet,” says he, “awaiting your longed-for and god-like approach.” And at another time, writing to Themista, he says, “That he had determined to make his way with her,” as Theodorus tells us in the fourth book of his treatises against Epicurus.

He also wrote to many other courtesans, and especially to Leontium, with whom Metrodorus also was in love. And in his treatise on the Chief Good, he writes thus, “For I do not know what I can consider good, if I put out of sight the pleasures which arise from flavors, and those which are derived from amatory pleasures, and from music and from the contemplation of beauty.” And in his letter to Pythocles, he writes, “Set sail, my dear boy, and avoid all sorts of education.”

Epictetus also attacks him as a most debauched man, and reproaches him most vehemently, and so does Timocrates, the brother of Metrodorus, in his treatise entitled the Merry Guests, and this Timocrates had been a disciple in his school, though he afterwards abandoned it; and he says that he used to vomit twice a day, in consequence of his intemperance; and that he himself had great difficulty in escaping from this nocturnal philosophy, and that mystic kind of association.

He also accuses Epicurus of shameful ignorance in his reasoning, and still more especially in all matters relating to the conduct of life. And says that he was in a pitiable state of health, so that he could not for many years rise up from his sofa; and that he used to spend a mina a day on his eating, as he himself states in his letter to Leontium, and in that to the philosophers at Mitylene. He also says that many courtesans used to live with him and Metrodorus; and among them Marmarium, and Hedeia, and Erotium, and Iridium.

And in the thirty-seven books which he wrote about natural philosophy, they say that he says a great many things of the same kind over and over again, and that in them he writes in contradiction of other philosophers, and especially of Nausiphanes, and speaks as follows, word for word: “But let them be gone. For this man had a continual labor, striving to bring forth the sophistical boastfulness of his mouth, like many other slaves.”

And Epicurus also speaks of Nausiphanes in his letters, in the following terms:  “These things led him on to such arrogance of mind, that he abused me and called me a schoolmaster.”  He used also to call him Lungs, and Blockhead, and Humbug, and Fornicator.  And he used to call Plato’s followers Flatterers of Dionysius, but Plato himself he called Golden.  Aristotle he called a debauchee and a glutton, saying that he joined the army after he had squandered his patrimony, and sold drugs.  He used to call Protagoras a porter, and the secretary of Democritus, and to say that he taught boys their letters in the streets.  Heraclitus, he called a disturber; Democritus, he nicknamed Lerocrates; and Antidorus, Samidorus; the Cynics he called the enemies of Greece; and the Dialecticians he charged with being eaten up with envy.  Pyrrhon, he said, was ignorant and unlearned.

But these men who say this are all wrong, for there are plenty of witnesses of the unsurpassable kindness of the man to everybody; both his own country which honored him with brazen statues, and his friends who are so numerous that they could not be counted in whole cities; and all his acquaintances who were bound to him by nothing but the charms of his doctrine, none of whom ever deserted him, except Metrodorus, the son of Stratoniceus, who went over to Carneades, probably because he was not able to bear with equanimity the unapproachable excellence of Epicurus.  Also, the perpetual succession of his school, which, when every other school decayed, continued without any falling off, and produced a countless number of philosophers, succeeding one another without any interruption.  We may also speak here of his gratitude towards his parents, and his kindness to his brothers, and his gentleness to his servants (as is plain from his will, and from the fact too, that they united with him in his philosophical studies, and the most eminent of them was the one whom I have mentioned already, named Inus); and his universal philanthropy towards all men.

His piety towards the gods, and his affection for his country was quite unspeakable; though, from an excess of modesty, he avoided affairs of the state. And though he lived when very difficult times oppressed Greece, he still remained in his own country, only going two or three times across to Ionia to see his friends, who used to throng to him from all quarters, and to live with him in his garden, as we are told by Apollodorus (this garden he bought for eighty minae).

And Diocles, in the third book of his Overview, says that they all lived in the most simple and economical manner; “They were content,” says he, “with a small cup of light wine, and all the rest of their drink was water.” He also tells us that Epicurus would not allow his followers to throw their property into a common stock, as Pythagoras did, who said that the possessions of friends were held in common. For he said that such a doctrine as that was suited rather for those who distrusted one another; and that those who distrusted one another were not friends. But he himself in his letters, says that he is content with water and plain bread, and adds, “Send me a cup, so that if I wish to have a feast, I may have the means.” This was the real character of the man who laid down the doctrine that pleasure was the chief good; who Athenaeus thus mentions in an epigram:

O men, you labor for pernicious ends;
And out of eager avarice, begin
Quarrels and wars. And yet the wealth of Nature
Fixes a narrow limit for desires,
Though empty judgment is insatiable.
This lesson the wise child of Neocles
Had learned by ear, instructed by the Muses,
Or at the sacred shrine of Delphi’s God.

And as we advance further, we shall learn this fact from his dogmas, and his maxims.  Of all the ancient philosophers he was, as we are told by Diocles, most attached to Anaxagoras (although on some points he argued against him); and to Archelaus, the master of Socrates. And, Diocles adds, he used to accustom his pupils to preserve his writings in their memory. Apollodorus, in his Chronicles, asserts that he was a pupil of Nausiphanes, and Praxiphanes; but he himself does not mention this; but says in his letter to Eurylochus, that he had been his own instructor. He also agreed with Hermarchus in not admitting that Leucippus deserved to be called a philosopher; though some authors, among whom is Apollodorus, speak of him as the master of Democritus. Demetrius the Magnesian says that he was a pupil of Xenocrates also.

He uses plain language in his works with respect to anything he is speaking of, for which Aristophanes, the grammarian, blames him, on the ground of that style being vulgar. But he was such an admirer of perspicuity, that even in his treatise on Rhetoric, he aims at and recommends nothing but clearness of expression.

And in his letters, instead of the usual civil expressions, “Greeting,” “Farewell,” and so on, he substitutes, “May you act well,” “May you live virtuously,” and expressions of that sort. Some of his biographers assert that it was he who composed the treatise entitled the Canon, in imitation of the Tripod of Nausiphanes, whose pupil they say that he was, and add that he was also a pupil of Pamphilus, the Platonist at Samos.

They further tell us that he began to study philosophy at twelve years of age, and that he presided over his school thirty-two years. And he was born as we are told by Apollodorus, in his Chronicles, in the third year of the hundred and ninth Olympiad, in the archonship of Sosigenes, on the seventh day of the month Gamelion, seven years after the death of Plato. And when he was thirty-two years of age, he first set up his school at Mitylene, and after that at Lampsacus; and when he had spent five years in these two cities, he came to Athens; and he died there in the second year of the hundred and twenty-seventh Olympiad, in the archonship of Pytharatus, when he had lived seventy-two years. And Hermarchus, the son of Agemarchus, and a citizen of Mitylene, succeeded him in his school.

He died of the stone, as Hermarchus mentions in his letters, after having been ill a fortnight; and at the end of the fortnight, Hermippus says that he went into a brazen bath, properly tempered with warm water, and asked for a cup of pure wine and drank it; and having recommended his friends to remember his doctrines, he expired. And there is an epigram of ours on him, couched in the following language:

“Now, farewell, remember all my words;”
This was the dying charge of Epicurus.
Then to the bath he went, and drank some wine,
And sank beneath the cold embrace of Hades.
Such was the life of the man, and such was his death.

 The Will of Epicurus

And he made his will in the following terms:

According to this, my will, I give all my possessions to Amynomachus, of Bate, the son of Philocrates, and to Timocrates, of Potamos, the son of Demetrius; according to the deed of gift to each, which is deposited in the Metroum; on condition that they make over my garden and all that is attached to it to Hermarchus, of Mitylene, the son of Agemortus; and to those who study philosophy with him, and to whomsoever Hermarchus leaves as his successors in his school, that they may abide and dwell in it, in the study and practice of philosophy; and I give it also to all those who study philosophy according to my doctrines, that they may, to the best of their ability, maintain my school which exists in my garden, in concert with Amynomachus and Timocrates; and I enjoin their heirs to do the same in the most perfect and secure manner that they can; so that they also may maintain my garden, as those also shall to whom my immediate successors hand it down. As for the house in Melita, that Amynomachus and Timocrates shall allow Hermarchus that he may live in it during his life, together with all his companions in philosophy.

Out of the income which is derived from that property, which is here bequeathed by me to Amynomachus and Timocrates, I will that they, consulting with Hermarchus, shall arrange in the best manner possible the offerings to the names in honor of the memory of my father, and mother, and brothers, and myself, and that my birthday may be kept as it has been in the habit of being kept, on the tenth day of the month Gamelion; and that the reunion of all the philosophers of our school, established in honor of Metrodorus and myself, may take place on the twentieth day of every month. They shall also celebrate, as I have been in the habit of doing myself, the day consecrated to my brothers, in the month Poseideon; and the day consecrated to memory of Polyaenus, in the month Metageitnion.

Amynomachus and Timocrates shall be the guardians of Epicurus, the son of Metrodorus, and of the son of Polyaenus, as long as they study philosophy under, and live with Hermarchus. In the same way also, they shall be the guardians of the daughter of Metrodorus, and when she is of marriageable age, they shall give her to whomsoever Hermarchus shall select of his companions in philosophy, provided she is well behaved and obedient to Hermarchus. And Amynomachus and Timocrates shall, out of my income, give them such a sum for their support as shall appear sufficient year by year, after due consultation with Hermarchus.

And they shall associate Hermarchus with themselves in the management of my revenues, in order that everything may be done with the approval of that man who has grown old with me in the study of philosophy, and who is now left as the president of all those who have studied philosophy with us. And as for the dowry for the girl when she is come to marriageable age, let Amynomachus and Timocrates arrange that, taking for the purpose such a sum from my property as shall seem to them, in conjunction with Hermarchus, to be reasonable.

And let them also take care of Nicanor, as we ourselves have done; in order that all those who have studied philosophy with us, and who have assisted us with their means, and who have shown great friendship for us, and who have chosen to grow old with us in the study of philosophy, may never be in want of anything as far as our power to prevent it may extend. I further enjoin them to give all my books to Hermarchus; and, if anything should happen to Hermarchus before the children of Metrodorus are grown up, then I desire that Amynomachus and Timocrates, shall take care that, provided they are well behaved, they shall have everything that is necessary for them, as far as the estate which I leave behind me shall allow such things to be furnished to them. And the same men shall also take care of everything else that I have enjoined; so that it may all be fulfilled, as far as the case may permit. Of my slaves, I hereby emancipate Mys, and Nicias, and Lycon: I also give Phaedrium her freedom.

And when he was at the point of death, he wrote the following letter to Idomeneus:

Letter to Idomeneus

We have written this letter to you on a happy day to us, which is also the last day of our life. For stranguary has attacked me, and also a dysentery, so violent that nothing can be added to the violence of my sufferings. But the cheerfulness of my mind, which arises from the recollection of all my philosophical contemplation, counterbalances all these afflictions. And I beg you to take care of the children of Metrodorus, in a manner worth of the devotion shown by the youth to me, and to philosophy.

Such then as I have given it, was his will.

He had a great number of pupils, of whom the most eminent included Metrodorus, the son of Athenaeus or Timocrates and Sande, of Lampsacus; who, from the time that he first became acquainted with him, never left him, except one when he went home for six months, after which he returned to him.

And he was a virtuous man in every respect, as Epicurus tells us in his Fundamental Principles. And he also bears witness to his virtue in the third book of his Timocrates. And being a man of this character, he gave his sister Batis in marriage to Idomeneus; and he himself had Leontium, the Attic courtesan, for his concubine. He was very unmoved at all disturbances, and even at death; as Epicurus tells us, in the first book of his Metrodorus. He is said to have died seven years before Epicurus himself, in the fifty-third year of his age. And Epicurus himself, in the will which I have given above, gives many charges about the guardianship of his children, showing by this that he had been dead some time. He also had a brother whom I have mentioned before, of the name of Timocrates, a trifling, silly man.

The writings of Metrodorus are these:

·         three books addressed to Physicians;

·         one essay on the Sensations;

·         one addressed to Timocrates;

·         one on Magnanimity;

·         one on the Illness of Epicurus;

·         one addressed to the Dialecticians;

·         nine books against the Sophists;

·         one on the Road to Wisdom;

·         one on Change;

·         one on Riches;

·         one against Democritus;

·         one on Nobility of Birth.


Likewise Polyaenus, of Lampsacus, the son of Athenodorus, was a man of mild and friendly manners, as Philodemus particularly assures us.

And his successor was Hermarchus, of Mitylene, the son of Agemortus (a poor man), whose favorite pursuit was rhetoric. And the following excellent works of his are extant:

·         twenty-two books of letters about Empedocles;

·         an essay on Mathematics;

·         a treatise against Plato;

·         another against Aristotle.

And he died of paralysis, being a most eminent man.

There was also Leonteus, of Lampsacus, and his wife Themista, to whom Epicurus wrote.

There were also Colotes and Idomeneus; and these also were natives of Lampsacus. And among the most eminent philosophers of the school of Epicurus, were Polystratus, who succeeded Hermarchus, and Dionysius who succeeded him, and Basileides who succeeded him. Likewise Apollodorus, who was nicknamed the tyrant of the garden, was a very eminent man, and wrote more than four hundred books. And there were the two Ptolemaei of Alexandria, Ptolemaeus the Black, and Ptolemaeus the Fair. And Zenon of Sidon, a pupil of Apollodorus, a very voluminous author; and Demetrius, who was surnamed the Laconian; and Diogenes of Tarsus, who wrote the Select Dialogues; and Orion, and others whom the genuine Epicureans call Sophists.

There were also three other persons of the name of Epicurus; first, the son of Leonteus and Themista; secondly, a native of Magnesia; and lastly, a gladiator.

And Epicurus was a most voluminous author, exceeding all men in the number of his books; for there are more than three hundred volumes of them; and in the whole of them there is not one citation from other sources, but they are filled wholly with the sentiments of Epicurus himself. In the quantity of his writings he was rivaled by Chrysippus, as Carneades asserts, who calls him a parasite of the books of Epicurus; for if ever this latter wrote anything, Chrysippus immediately set his heart on writing a book of equal size; and in this way he often wrote the same thing over again; putting down whatever came into his head; and he published it all without any corrections, by reason of his haste. And he quotes such numbers of testimonies from other authors, that his books are entirely filled with them alone; as one may find also in the works of Aristotle and Zenon.

Such then, so numerous are the works of Epicurus; the chief of which are the following:

·         thirty-seven treatises on Natural Philosophy;

·         one on Atoms and the Void;

·         one on Love;

·         an abridgment of the Arguments employed against the Natural Philosophers;

·         one against the Doctrines of the Megarians;

·         Problems;

·         Fundamental Propositions;

·         a treatise on Choice and Avoidance;

·         another on the Chief Good;

·         another on the Criterion, called also the Canon;

·         Chaeridemus, a treatise on the Gods;

·         one on Piety;

·         Hegesianax

·         four essays on Lives;

·         one on Just Dealing;

·         Neocles;

·         one essay addressed to Themista;

·         the Banquet;

·         Eurylochus;

·         one essay addressed to Metrodorus;

·         one on Seeing;

·         one on the Angle in an Atom;

·         one on Touch;

·         one on Fate;

·         Opinions on the Passions;

·         one treatise addressed to Timocrates;

·         Prognostics;

·         Exhortations;

·         a treatise on Images;

·         one on Perceptions;

·         Aristobulus;

·         an essay on Music;

·         one on Justice and the other Virtues;

·         one on Gifts and Gratitude;

·         Polymedes;

·         Timocrates, a treatise in three books;

·         Metrodorus, in five books;

·         Antidorus, in two books;

·         Opinions about Diseases, addressed to Mithras;

·         Callistolas;

·         an essay on Kingly Power;

·         Anaximenes;

·         Letters.


And I will endeavor to give an abridgment of the doctrines contained in these works, as it may be agreeable, quoting three letters of his, in which is the epitome of all his philosophy.  I will also give his fundamental and peculiar opinions, and any adages which he uttered which appear worthy of being selected, so that you may be thoroughly acquainted with the man, and may also judge that I understand him.

Now the first letter is one that he wrote to Herodotus, on the subject of Natural Philosophy; the second is one that he wrote to Pythocles, which is about the Heavenly Bodies; the third is addressed to Menoeceus, in which there are discussions about how to live.

We must now begin with the first, after having said a little by way of preface concerning the divisions of philosophy which he adopted.

Now he divides philosophy into three parts. The canonical, the physical, and the ethical.  The canonical, which serves as an introduction to knowledge, is contained in the single treatise which is called the Canon. The physical embraces the whole range of speculation on subjects of natural philosophy, and is contained in the thirty-seven books on Nature, and in the letters again it is discussed in an elementary manner. The ethical contains the discussions of Choice and Avoidance; and is comprised in the books about lives, and in some of the Letters, and in the treatise of the Chief Good. Accordingly, most people are in the habit of combining the canonical divisions with the physical; and then they designate the whole under the names of the criterion of the truth, and a discussion of principles, and elements. And they say that the physical division is concerned with production, and destruction, and Nature; and that the ethical division has reference to the objects of choice and avoidance, and lives, and the chief good of mankind.

Dialectics they wholly reject as superfluous. For they say that the correspondence of words with things is sufficient for the natural philosopher to enable him to advance with certainty in the study of Nature.

Now, in the Canon, Epicurus says that the criteria of truth are the senses, and the preconceptions, and the passions. But the Epicureans, in general, add also the perceptive impressions of the intellect. And he says the same thing in his Abridgment, which he addresses to Herodotus, and also in his Fundamental Principles. For, says he, the senses are devoid of reason, nor are they capable of receiving any impressions of memory. For they are not by themselves the cause of any motion, and when they have received any impression from any external cause, then they can add nothing to it, nor can they subtract anything from it. Moreover, they are out of the reach of any control; for one sensation cannot judge of another which resembles itself; for they have all an equal value. Nor can one judge of another which is different from itself; since their objects are not identical. In other words, one sensation cannot control another, since the effects of all of them influence us equally. Again, Reason cannot pronounce on the senses; for we have already said that all reasoning has the senses for its foundation. Reality and the evidence of sensation establish the certainty of the senses; for the impressions of sight and hearing are just as real, just as evident, as pain.

It follows from these considerations that we ought to judge of things which are obscure by their analogy to those which we perceive directly. In fact, every notion proceeds from the senses, either directly, or in consequence of some analogy, or proportion, or combination, reasoning having always a share in these last operations. The visions of insanity and of sleep have a real object for they act upon us; and that which has no reality can produce no action.

By preconception, the Epicureans meant a sort of comprehension as it were, or right opinion, or notion, or general idea which exists in us; or, in other words, the recollection of an external object often perceived beforehand.  Such for instance, is the idea: “Man is being of such and such Nature.” At the same moment that we utter the word man, we conceive the figure of a man, in virtue of a preconception which we owe to the preceding operations of the senses.  Therefore, the first notion which each word awakens in us is a correct one.  In fact, we could not seek for anything if we had not previously some notion of it.  To enable us to affirm that what we see at a distance is a horse or an ox, we must have some preconception in our minds which makes us acquainted with the form of a horse and an ox. We could not give names to things, if we had not preliminary notion of what the things were.

These preconceptions then furnish us with certainty. And with respect to judgments, their certainty depends on our referring them to some previous notion, of itself certain, in virtue of which we affirm such and such a judgment; for instance, “How do we know whether this thing is a man?”

The Epicureans also refer to ‘opinion’ as supposition, and say that it is at times true, and at times false.  For that which is supported by evidence and not contradicted by evidence is true; but if it is not supported by evidence, and is contradicted by evidence, then it is false.  On which account they have introduced the expression of “waiting,” as when, before pronouncing that a thing seen is a tower, we must wait till we come near, and learn what it looks like when we are near it.

They say that there are two passions, pleasure and pain, which affect everything alive. And that the one is natural, and the other foreign to our Nature; with reference to which all objects of choice and avoidance are judged of. They say also, that there are two kinds of investigation; the one about facts, the other about mere words. And this is as far as an elementary sketch can go – their doctrine about division, and about the criterion.

Let us now go to his letter:

Letter to Herodotus

Epicurus to Herodotus, wishing he may do well.

For those, Herodotus, who are not able accurately to comprehend all the things which I have written about Nature, nor able to investigate those larger books which I have composed on the subject, I have made an abridgment of the whole discussion on this question as far as I thought sufficient to enable them to recollect accurately the most fundamental points.  I have done this so that on all occasions, they might be able to assist themselves on the most important and undeniable principles to the extent that they devote themselves to studies on natural philosophy. And here it is necessary for those who have made sufficient progress in their overview of the general question, to recall the principles laid down as elements of the entire discussion.  For we have a greater need of a correct understanding of the whole than we have of the details. We must therefore give preference to the knowledge we have already acquired, and lay up in our memory those principles on which we may rest, in order that we may arrive at an exact perception and a certain knowledge of things.

Now, one has arrived at the point of certain knowledge when one has thoroughly embraced the concept, and if I may so express myself, the most essential forms, and when one has impressed them adequately on one’s senses.  For the clear and precise knowledge of the whole, taken together, necessarily facilitates one’s perceptions of particulars, when one has brought one’s ideas back to the elements and the fundamental terms. In short, a true synthesis, comprising the entire circle of the phenomena of the universe, ought to be able to encompass in itself, and in a few words, all the particular facts which have been previously studied. This method is useful even to those who are already familiarized with the laws of the universe, and I recommend that they make a concise statement or summary of their opinions, while still pursuing without intermission the study of Nature, which contributes more than anything else to the tranquility and happiness of life.

First of all then, Herodotus, one must determine with exactness the concept which is comprehended under each separate word, in order to be able to refer to that concept, as to a certain criterion. To these conceptions, which emanate from ourselves, we refer back as we examine our greatest researches and difficulties; otherwise our judgment has no foundation.  One’s understanding goes on from demonstration to demonstration ad infinitum; or else one gains nothing beyond mere words.  In fact, it is absolutely necessary that we should perceive directly, and without the assistance of any demonstration, the fundamental concept which every word expresses.  We must do this, if we wish to have any foundation to which we may refer our researches, our difficulties, and our personal judgments.  And we must take care to perceive these concepts clearly using whatever criterion which we employ, whether we take as our standard the particular impressions produced on our senses, or the actual impression as a general concept; or whether we cling to the idea by itself, or whether we employ any other criterion.

We must also note carefully the impressions which we receive when we are in the very presence of objects.  We must do this in order that we may identify that point in the examination where we find it necessary to reserve judgment as to the truth of a matter, especially when the question is about things of which we do not have immediately perceptible to us sufficient evidence to form a clear determination on the matter.

When these foundations are once laid, we may pass to the study of those things about which the evidence is not immediately clear to us.  [On questions such as this there are a number of fundamental principles of nature which we must keep in mind:]

First of all, we must admit that nothing can come from that which does not exist. Were this fact otherwise, then everything would be produced from everything, and there would be no need of any first beginning, or seed.

Second, if that which disappeared were so absolutely destroyed as to become non-existent, then everything would soon perish, as the things into which they would be dissolved would have no existence.

As a result of these first two principles, we conclude that the universe as a whole has always been such as it now is and always will be such.  For there is nothing into which the universe can change, and there is nothing beyond the universal whole which can penetrate into the universal whole and produce any change in it.[i]

Next, we observe that everything that exists in the universe is formed from bodies that have a material existence of some kind.  We know this because our senses bear us witness in every case that bodies have a real existence, and the evidence of the senses, as I have said before, ought to be the rule of our reasoning about everything, even that which we are not able to perceive directly.  We also consider that that that which we call the void, or space, or intangible Nature, has a real existence, as otherwise there would be nothing on which the bodies could be contained, or across which they could move, as we see that they really do move.  As a result of these observations we conclude that one cannot conceive, either through human perception, or through any analogy founded on perception, any general quality of things which is not either an attribute, or an incident of material things or empty space, which we call matter and void.[ii]

Now, of material things, some single elements, and others are formed of combinations of elements.  The elements are indivisible, and thus are impervious to any kind of transformation; if this were not so everything would eventually dissolve into non-existence. The elements exist by their own nature, even though the combined bodies which they compose change and dissolve, because the elements are absolutely solid, and as such they offer no point through which any destructive force can enter.  It follows, therefore, as a matter of absolute necessity, that the fundamental material of the universe must be composed of elements that are themselves indivisible.

The universe is boundless. We know this because that which is bounded has an extreme point, and that which has an extreme point is looked at in relationship to something else. Consequently, that which does not have an extreme point has no boundary.  And if it has no boundary, it must be infinite, and not terminated by any limit.  The universe then is infinite, both in regard to the quantity of matter from which it is made up, and to the magnitude of the void.  For if the void were infinite, and the amount of matter was finite, then the matter would not be able to rest in any place.  The elements of the universe would be transported about, scattered across the infinite void, lacking any power to steady itself, or to keep one another in their places by mutual repulsion.  If, on the other hand, the void were finite, while the amount of the matter was infinite, then the elements clearly could never be contained in the void.

Again: the atoms within the combined bodies, and these solid elements from which the combined bodies come, and into which they resolve themselves, assume an incalculable variety of forms.  This must be so because the numerous differences which the bodies present to us cannot possibly result from an aggregate of the same forms. Each type of form that we observe contains an innumerable number of atoms, but there is not for that reason an infinity of atoms; it is only that their number is beyond all calculation.[iii]

The atoms are in a continual state of motion.[iv] Among these atoms, some are separated by great distances, but others come very near to one another in the formations of combined bodies, or at times they are enveloped by others which are combining.  However, in this latter case, they nevertheless preserve their own peculiar motion, thanks to the Nature of the void which separates the one from the other, and yet offers them no resistance.  The solidity which they possess causes them, while knocking against one another, to react one upon the other; till at last the repeated shocks bring on the dissolution of the combined body.  For all this there is no external cause, the only cause is the fundamental nature of the atoms and the void.[v]

Further, the number of worlds are also infinite, whether they resemble this one of ours or whether they are different from it.  For the atoms are, as to their number, infinite, as I have shown above, and they necessarily move about at immense distances.  The infinite multitude of atoms of the universe from which this world is formed, or by which it is produced, could not be entirely absorbed by one single world, nor even by any finite number of worlds, whether we suppose all those worlds to be like our own, or different form it.  We see that there is therefore no fact inconsistent with there being an infinity of worlds.

Moreover, we observe that there exist what we call images that resemble, as far as their form goes, the solid bodies which we see, but which differ materially from them in the thinness of their substance.  In fact it is not impossible but that there may be in space images that form surfaces without depth, of an extreme thinness.  It is also possible that from the solid matter there may emanate some particles which preserve the connection, the disposition, and the motion which they had in the solid body.  I give the name of images to these representations; and indeed, their movement through the void takes place without meeting any obstacle or hindrance.  These images traverse all imaginable distances in an inconceivable moment of time; for it is the meeting of obstacles, or the absence of obstacles, which produces the rapidity or the slowness of their motion.  At any event, a body in motion does not find itself, no matter how fast it is traveling, in two places at the same time, as that is quite inconceivable.  From what ever point within the infinite universe it arrives at any appreciable moment, and whatever may be the spot in it its course in which we perceive its motion, it has evidently quitted that spot at the moment of our thought.  This is because the motion of the images in space, as we have shown up to this point, encounters no obstacle to its rapidity, and it is wholly in the same condition as it would be if its rapidity had been diminished by the shock of some resistance.

It is useful to retain this principle in our studies, and to know that the images have an incomparable thinness.  This fact is in no respect contradicted by the evidence of our senses.  From this it also follows that the rapidity of movement of the images is incomparable; for they find everywhere an easy passage, and their minuteness causes them to experience no shock, or at any event only a very slight one, where a multitude of elements would very soon encounter significant resistance.

One must not forget that the production of images is continuous; for from the surface of the bodies images of this kind are continually flowing off in a manner too fast for our senses to apprehend, because they are immediately replaced. They preserve for a long time the same disposition and the same arrangement that the atoms do in the solid body, although their form may be sometimes altered. The direct production of images in space is equally instantaneous, because these images are only light substances that lack any depth.

[As we consider phenomena such as the nature of sight and images], we may consider that there may be [various] other manners in which phenomena of this kind are produced, but we must allow nothing in these other possibilities which at all contradicts the senses, and we must consider in what way the senses are exercised and the relationship that is established between external objects and ourselves.  In this inquiry, one must admit that something passes over from external objects to us in order to produce in us sight and the knowledge of forms, for it is difficult to conceive that external objects can affect us through the medium of the air which is between us and them, or by means of emissions that proceed from us to them, and still give us an impression of their form and color.  This phenomenon, on the contrary, is perfectly explained if we admit that certain images of the same color, of the same shape, and of a proportionate magnitude pass from these objects to us, and so arrive at us, being seen and comprehended.  These images travel at an exceedingly rapid speed, and the vision is continued so long as on the other side, the solid object, which forms a compact mass comprising a vast quantity of atoms, emits always the same quantity of particles.  In this way the images produce in us one single perception which preserves always the same relation to the object.  Every conception we form, every sensible perception we receive which bears upon the form or the other attributes of these images, is only the same form of the solid object perceived directly, either in virtue of a sort of actual and continued condensation of the image, or in consequence of the traces which it has left in us.

This leads us to observe the possibility of error and false judgments, which always depend upon our supposing that a preconceived idea will be confirmed, or at any event will not be overturned, by additional evidence as we receive it. In those cases where our supposition is not confirmed, we form our judgments in virtue of a sort of initiation of thought which is connected with our perceptions, and with a direct representation from the object that we observe.  In these cases of error, however, the connection is with a conception that is peculiar to ourselves, and this is the parent of error. In fact, the representations we receive from images are reflected by our intelligence like a mirror, whether those images are perceived in a dream or through any other conceptions of the mind or the senses.  But these representations do not resemble the objects to the extent that we can call them real and true unless the objects that we are examining are perceived directly.  Error arises when we do not perceive objects directly because in those situations we receive impressions which our intelligence connects with a direct representation, but which goes beyond a direct observation. These conceptions are connected with direct perception which produced the representation, but they go beyond the actual object in consequence of impressions that are peculiar to the individual making them.  This results in error when the mental apprehension our minds reach is not confirmed by, or is contradicted by, additional evidence.  When our mental apprehension is confirmed by additional evidence, or when it is not contradicted by additional evidence, then it produces truth.

We must carefully preserve these principles in order that we will not reject the authority of those of our faculties which perceive truth directly. We must also observe these principles so that we will not allow our minds to believe that what is false or what is speculative has been established with equal firmness with what is true, because this results in everything being thrown into confusion.

Moreover, hearing is produced by some sort of flow proceeding from something that speaks, or sounds, or roars, or in any manner causes any sort of audible circumstances.  And this flow is diffused into small bodies which resemble one another in their parts, and which, preserve not only some kind of relation between one another, but even a sort of particular identity with the object from which they emanate.  This process puts us, very frequently, into a communication of senses with this object, or at least causes us to become aware of the existence of some external circumstance. If these flows did not carry with them some sort of sympathy, then there would be no such perception. We must not therefore think that it is the air which receives a certain form, under the action of the voice or some other sound. For it is not possible that the voice should act in this manner on the air.  But the percussion produced in us when we, by the utterance of a voice, cause a disengagement of certain particles, constitutes a flow resembling a light whisper, and prepares an acoustic sensation in us.

We must admit that the case of smelling is the same as that of hearing.  There would be no sense of smell if there did not emanate from objects certain particles capable of producing an impression on the sense of smell.  One class of smells is ill-suited to ours sense of smell, and consequently producing a disordered response, the other class of smells suited to our senses, and causing it no distress.

One must also allow that the atoms possess none of the qualities of objects perceptible to our senses except form, weight, magnitude, and anything else that is unavoidably inherent in form.  Every transient quality is changeable, but the atoms are necessarily unchangeable.  This is because there must be in the dissolution of combined bodies something which continues solid and indestructible.  Such basic material is of such a kind that it will not change either into what does not exist, or out of what does not exist; but combined bodies result either from a simple rearrangement of parts, or from the addition or subtraction of certain particles.  It follows that those basic elements which do not admit of any change in themselves are imperishable, and participate in no respect in the nature of changeable things  In a word, these basic materials have their dimensions and forms immutable determined.  And this is proved plainly enough, because even in the transformations which take place under our eyes in consequence of the removal of certain parts, we can still recognize the form of the constituent parts.  In contrast, those qualities which are not constituent parts do not remain like the form, but perish in the dissolution of the combination.  The attributes which we have indicated are sufficient to explain all the differences of combined bodies, but in the basic materials must inevitably leave something indestructible, lest everything should resolve itself into non-existence.

However, one must not believe that every degree of magnitude exists in atoms, lest we find ourselves contradicted by what we observe.  But we must observe that there are atoms of different magnitudes, because we may then more easily explain our impressions and sensations.  In any event, I repeat, it is not necessary for the purpose of explaining the different qualities that we observe to attribute to the atoms every kind of magnitude.

We must not suppose either, that an atom can be so large as to become visible to us.  First of all, we do not observe that this is the case.  In addition, one cannot even conceive how an atom is to become visible; and we must not believe that in a finite body there are particles of every sort, infinite in number.  Consequently, one must reject the doctrine of infinite divisibility into material that is smaller and smaller, lest we should be reducing everything to nothing, and find ourselves forced to admit that in a mass composed of a combination of elements, existence can reduce itself to non-existence.

But one cannot even suppose that a finite thing can be susceptible of transformation ad infinitum, or even of transformation into smaller objects that itself.  Once one has said that there are in an object particles of every kind, and in infinite number, there is absolutely no means whatever of imagining that this object can have only a finite size.  In fact, it is evident that these particles, though innumerable, have some kind of dimension or other.  Whatever this dimension may be in other respects, the objects which are composed of them will have an infinite magnitude.  As we examine forms which are determined and limits which are perceived by the senses, however, one conceives easily without it being necessary to study the question that objects composed of infinite material would be infinite in size.  Consequently, one must come to look at every object composed of a finite number of elemental particles.

One must also admit that the most minute particle perceptible to the senses is neither absolutely like the objects which are susceptible of change nor absolutely different from them.  Such an object has some characteristics in common with the object from which it was a part, but it also differs from them, inasmuch as it itself does not allow any distinct parts to be discerned within it.  When then, in virtue of these common characteristics and of this resemblance, we wish to form an idea of the smallest particle perceptible by the senses, it is necessary that we should seize on some characteristic common to these different objects for our terms of comparison.  In this way, we examine them successively, from the first to the last, not by themselves, but more as composed of parts in juxtaposition, but only in their extent.  In other words, we consider the magnitudes by themselves, and in an abstract manner, inasmuch as they measure a greater or smaller extent. This analogy applies to the atom to the extent that we consider it as having the smallest dimensions possible.  By evidence of its minuteness it differs from objects which are perceptible, but still this analogy is applicable to it.  In a word, we establish by this comparison, that the atom really has some extent, but we exclude all perceptible dimensions for the sake of investing it with only the smallest proportions.

We may proceed further, taking for our guide the reasoning which discloses to us things which are invisible to the senses.  We conclude that the most minute magnitudes, those which are not combinations of other magnitudes, are those which from the limit of our senses are the first measure of the other magnitudes, which are only called greater or lesser in their relation to the others.  For these relations which they maintain with those particles which are not subject to transformation, we suffice it to give them this characteristic of first measure.  But they cannot, like atoms, combine themselves and form compound bodies in virtue of any motion belonging to themselves.

Moreover, when we are speaking of the infinite we must not say that such or such a point is the highest point, or the lowest. For height and lowness must not be attributed to what is infinite.  This is because we know that in reality, if we wish to describe a limit to the infinite, and we conceive a point above our head, this point wherever it may be, will never appear to us to have the character of a limit.  Otherwise, that which would be situated above the point so conceived as the limit of the infinite would be at the same moment both high and low in relation to the same point, and this is impossible to imagine.

It follows that thought can only conceive one single movement of change, from low to high, ad infinitum; and one single movement from high to low. From low to high, when even the object in motion, going from us to the places situated above our heads, meets ten thousand times with the feet of those who are above us; and from high to low, when in the same way it advances towards the heads of those who are below us. For these two movements, looked at by themselves and in their whole, are conceived as really opposed the one to the other, in their progress towards the infinite.

Moreover, all the atoms are necessarily moving at the same speed when they move across the void, when no obstacle thwarts them.  For why should heavy atoms move more rapidly than those which are small and light, since neither encounter any obstacle?  Why, on the other hand, should the small atoms have a speed superior to that of the large ones, since both sizes find an easy passage everywhere, with no obstacle intervening to thwart their movements?  Whether the movement is from low to high or is horizontal movement to and fro in virtue of the reciprocal collisions of the atoms, or is movement downwards in virtue of weight, the speed of all such movement will be all equal, for in whatever sense the atom moves, it must have a movement as rapid as we can comprehend till the moment when it is repelled by some external cause, or meets resistance due to its own weight or the shock of collision with some other object.

Again, even in compound bodies, one atom does not move more rapidly than another.  In fact, if one only looks at the continued movement of an atom which takes place in an indivisible moment of time, which is the briefest possible, they all have a movement that is equally rapid.  At the same time, an atom does not continue its movement in the same direction in any period of time we can perceive.  Rather the atom moves in a series of oscillating movements, and in the last analysis it is from this that results the continued movement of things that is perceptible to the senses.  One would therefore deceive himself if he were to suppose, when reasoning about invisible things, that in the short intervals of time which we can conceive the atoms continue to move in the same direction, for our conception of the oscillating movements of atoms is confirmed by our observation of what we perceive directly.

Let us now return to the study of the passions, and of the sensations; for this will be the best method of proving that the soul is a bodily substance, which we believe is composed of light particles, diffused over all the members of the body.  In this way the soul presents an analogy to a sort of spirit, having an mixture of heat, resembling at various time one or thee other of these two principles  spirit and heat. Also within the soul there exists a special part, endowed with extreme mobility and in immediate sympathy with the rest of the body, due to the exceeding slightness of the elements which compose it. That it is which the faculties of the soul sufficiently prove, and the passions, and the mobility of its Nature, and the thoughts, and, in a word, everything, the privation of which is death. We must admit that it is in the soul most especially that the principle of sensation resides. At the same time, it would not possess this power if it were not enveloped by the rest of the body which communicates it to it, and in its turn receives it from it; but only in certain measure; for there are certain affections of the soul of which it is not capable.

It is on that account that, when the soul departs, the body is no longer possessed of sensation; for it has not this power, (namely that of sensation) in itself; but on the other hand, this power can only manifest itself in the soul through the medium of the body. The soul, reflecting the manifestations which are accomplished in the substance which environs it, realizes in itself, in a virtue or power which belongs to it, the sensible affections, and immediately communicates them to the body in virtue of the reciprocal bonds of sympathy which unite it to the body; that is the reason why the destruction of a part of the body does not draw after it a cessation of all feeling in the soul while it resides in the body, provided that the senses still preserve some energy; although, nevertheless, the dissolution of the corporeal covering, or even of any one of its portions, may sometimes bring on with it the destruction of the soul.

The rest of the body, on the other hand, even when it remains, either as a whole, or in any part, loses all feeling by the dispersion of that aggregate of atoms, whatever it may be, that forms the soul. When the entire combination of the body is dissolved, then the soul too is dissolved, and ceases to retain those faculties which were previously inherent in it, and especially the power of motion; so that sensation perishes equally as far as the soul is concerned; for it is impossible to imagine that it still feels, from the moment when it is no longer in the same conditions of existence, and no longer possesses the same movements of existence in reference to the same organic system; from the moment, in short, when the things which cover and surround it are no longer such, that it retains in them the same movements as before. (Epicurus expresses the same ideas in other works, and adds that the soul is composed of atoms of the most perfect roundness and lightness; atoms wholly different from those of fire. He distinguishes in it the irrational part which is diffused over the whole body, from the rational part which has its seat in the chest, as is proved by the emotions of fear and joy. He adds that sleep is produced either when the parts of the soul diffused over the whole of the body concentrate themselves, or when they disperse and escape by the pores of the body; for particles emanate from all bodies.)

It must also be observed that I use the word incorporeal in the usual meaning of the word, to express that which is in itself conceived as such. Now, nothing can be conceived in itself as incorporeal except the void; but the void cannot be either passive or active; it is only the condition and the place of movement. Accordingly, they who pretended that the soul is incorporeal, utter words destitute of sense; for if it had this character, it would not be able either to do or to suffer anything; but, as it is, we see plainly enough that it is liable to both these circumstances.

Let us then apply all these reasonings to the affections and sensations, recollecting the ideas which we laid down at the beginning, and then we shall see clearly that these general principles contain an exact solution of all the particular cases.

As to forms, and hues, and magnitudes, and weight, and the other qualities which one looks upon as attributes, whether it be of every body, or of those bodies only which are visible and perceived by the senses, this is the point of view under which they ought to be considered: they are not particular substances, having a peculiar existence of their own, for that cannot be conceived; nor can one say any more that they have no reality at all. They are not incorporeal substances inherent in the body, nor are they parts of the body. But they constitute by their union, I repeat, the eternal substance of the body. Each of these attributes has ideas and particular perceptions which correspond to it; but they cannot be perceived independently of the whole subject taken entirely. The union of all these perceptions forms the idea of the body. Bodies often possess other attributes which are not eternally inherent in them, but which nevertheless cannot be ranged among the incorporeal and invisible things. Accordingly, it is sufficient to express the general idea of the movement of transference to enable us to conceive in a moment certain distinct qualities, and those combined beings, which, being taken in their totality, receive the name of bodies; and the necessary and eternal attributes without which the body cannot be conceived.

There are certain conceptions corresponding to these attributes; but nevertheless, they cannot be known abstractedly, and independently of some subjects; and further, inasmuch as they are not attributes necessarily inherent in the idea of a body, one can only conceive them in the moment in which they are visible; they are realities nevertheless; and one must not refuse them being an existence merely because they have neither the characteristic of the compound beings to which we give the name of bodies, nor that of the eternal attributes. We should be equally deceived if we were to suppose that they have a separate and independent existence; for that is true neither of them nor of the eternal attributes. They are, as one sees plainly, accidents of the body; accidents which do not of necessity make any part of its Nature; which cannot be considered as independent substances, but still to each of which sensation gives the peculiar character under which it appears to us.

Another important question is that of time. Here we cannot apply any more the method of examination to which we submit other objects, where we study with reference to a give subject; and which we refer to the preconceptions which exist in ourselves. We must seize, by analogy, and going round the whole circle of things comprised under this general denomination for time – we must seize, I say, that essential character which causes us to say that time is long or short. It is not necessary for that purpose to seek for any new forms of expression as preferable to those which are in common use; we may content ourselves with those by which time is usually indicated. Nor need we, as certain philosophers do, affirm any particular attribute of time, for that would be to suppose that its essence is the same as that of this attribute. It is sufficient to seek for the ingredients of which this particular Nature which we call time is composed, and for the means by which it is measured.  For this we have no need of demonstration; a simple exposition is sufficient. It is, in fact, evident, that we speak of time as composed of days and nights, and parts of days and nights.  Passiveness and impassibility, movement and repose, are equally comprised in time. In short, it is evident that in connection with these different states, we can conceive a particular property to which we give the name of time.

(Epicurus lays down the same principles in the second book of his treatise on Nature, and in his Great Abridgment.)

It is from the infinite that the worlds are derived, and all the finite aggregates which present numerous analogies with the things which we observe under our own eyes. Each of these objects, great and small, has been separated from the infinite by a movement peculiar to itself. On the other hand, all these bodies will be successively destroyed, some more, and others less rapidly; some under the influence of one cause, and others because of the agency of some other. (It is evident, after this, that Epicurus regards the worlds as perishable, since he admits that their parts are capable of transformation. He also says in other places, that the earth rests suspended in the air.)

We must not believe that all worlds necessarily have one identical form. (He says, in fact, in the twelfth book of his treatise on the World, that the worlds differ from one another; some being spherical, other elliptical, and others of other shapes.)

Let us also beware of thinking that animals are derived from the infinite; for there is no one who can prove that the seeds from which animals are born, and plants, and all the other objects which we contemplate, have been brought from the exterior in such a world, and that this same world would not have been able to produce them of itself. This remark applies particularly to the earth.

Again, we must admit that in many and various respects, Nature is both instructed and constrained by circumstances themselves; and that Reason subsequently makes perfect and enriches with additional discoveries the things which it has borrowed from Nature; in some cases rapidly, and in others more slowly. And in some cases according to periods and times greater than those which proceed from the infinite; in other cases according to those which are smaller. So, originally it was only in virtue of express agreements that one gave names to things. But men whose ideas and passion varied according to their respective nations, formed these names of their own accord, uttering diverse sounds produced by each passion, or by each idea, following the differences of the situations and of the peoples. At a later period one established in each nation, in a uniform manner, particular terms intended to render the relations more easy, and language more concise. Educated men introduced the notion of things not discoverable by the senses, and appropriated words to them when they found themselves under the necessity of uttering their thoughts; after this, other men, guided in every point by reason, interpreted these words in the same sense.

As to the heavenly phenomena, such as the motion and course of the stars, the eclipses, their rising and setting, and all other appearances of the same kind, we must beware of thinking that they are produced by any particular being which has regulated, or whose business it is to regulate, for the future, the order of the world, a being immortal and perfectly happy.  For the cares and anxieties, the benevolence and the anger, far from being compatible with felicity, are, on the contrary, the consequence of weakness, of fear, and of the want which a thing has of something else. We must not fancy either that these globes of fire, which roll on in space, enjoy a perfect happiness, and give themselves, with reflection and wisdom, the motions which they possess. But we must respect the established notions on this subject, provided, nevertheless, that they do not all contradict the respect due to truth; for nothing is more calculated to trouble the soul than this strife of contradictory notions and principles. We must therefore admit that from the first movement impressed on the heavenly bodies since the organization of the world there is derived a sort of necessity which regulates their course to this day.

Let us be well assured that it is to physiology that it belongs to determine the causes of the most elevated phenomena, and that happiness consists, above all things, in the science of the heavenly things and their Nature, and in the knowledge of analogous phenomena which may aid us in the comprehension of ethics. These heavenly phenomena admit of several explanations; they have no reason of a necessary character, and one may explain them in different manners. In a word, they have no relation – a moment’s consideration will prove this by itself – with those imperishable and happy Natures which admit of no division and of no confusion.  As for the theoretical knowledge of the rising and setting of the stars, of the movement of the sun between the tropics, of the eclipses, and all other similar phenomena, that is utterly useless, as far as any influence upon happiness that it can have. Moreover, those who, though possessed of this knowledge, are ignorant of Nature, and of the most probable causes of the phenomena, are no more protected from fear than if they were in the most complete ignorance.  They even experience the most lively fears, for the trouble with which the knowledge of which they are possessed inspires them can find no issue, and is not dissipated by a clear perception of the reasons of these phenomena.

As to us, we find many explanations of the motions of the sun, of the rising and setting of the stars, of the eclipse and similar phenomena, just as well as of the more particular phenomena. And one must not think that this method of explanation is not sufficient to procure happiness and tranquility. Let us content ourselves with examining how it is that similar phenomena are brought about under our own eyes, and let us apply these observations to the heavenly objects and to everything which is known only indirectly. Let us despise those people who are unable to distinguish facts susceptible of different explanations from others which can only exist and be explained in one single way. Let us disdain those men who do not know, by means of the different images which result from distance, how to give an account of the different appearances of things; who, in a word, are ignorant about what are the objects which can excite any trouble in us. If, then, we know that such a phenomenon can be brought about in the same manner as another given phenomenon of the same character which does not inspire us with any apprehension; and if, on the other hand, we know that it can take place in many different manners, we shall not be more troubled at sight of it than if we know the real cause of it.

We must also recollect that which principally contributes to trouble the spirit of men is the persuasion which they cherish that the stars are beings imperishable and perfectly happy, and that then one’s thoughts and actions are in contradiction to the will of these superior beings. They also being deluded by these fables, apprehend an eternity of evils, and they fear the insensibility of death, as if that could affect them. What do I say? It is not even belief, but inconsiderateness and blindness which govern them in every thing, to such a degree that, not calculating these fears, they are just as much troubled as if they really had faith in these vain phantoms.

And the real freedom from this kind of trouble consists in being emancipated from all these things, and in preserving the recollection of all the principles which we have established, especially of the most essential of them. Accordingly, it is well to pay a scrupulous attention to existing phenomena and to the sensations, to the general sensations for general things, and to the particular sensations for particular things. In a word, we must take note of this, the immediate evidence with which each of these judicial faculties furnishes us; for, if we attend to these points, namely, whence confusion and fear arise, we shall divine the causes correctly, and we shall deliver ourselves from those feelings, tracing back the heavenly phenomena to their causes, and also all the other which present themselves at every step, and inspire the common people with extreme terror.

This, Herodotus, is a kind of summary and abridgment of the whole question of natural philosophy. So that, if this reasoning be allowed to be valid, and be preserved carefully in the memory, the man who allows himself to be influenced by it, even though he may not descend to a profound study of its details, will have a great superiority of character over other men. He will personally discover a great number of truths which I have myself set forth in my entire work; and these truths being stored in his memory, will be a constant assistance to him. By means of these principles, those who have descended into the details, and have studied the question sufficiently, will be able, in bringing all their particular knowledge to bear on the general subject, to run over without difficulty almost the entire circle of the natural philosophy; those, on the other hand, who are not yet arrived at perfection, and who have not been able to hear me lecture on these subjects, will be able in their minds to run over the main of the essential notions, and to derive assistance from them for the tranquility and happiness of life.

This then is his letter on physics.

Letter to Pythocles

About the heavenly bodies he writes thus:

THE LETTER TO PYTHOCLES, about the heavenly bodies

Epicurus to Pythocles, wishing he may do well.

Cleon has brought me your letter, in which you continue to evince towards me an affection worthy of the friendship which I have for you. You devote all your care, you tell me, to engraving in your memory those ideas which contribute to the happiness of life; and you entreat me at the same time to send you a simple abridgment and abstract of my ideas on the heavenly phenomena, in order that you may without difficulty preserve the recollection of them. For, say you, what I have written on this subject in my other works is difficult to recollect, even with continual study.

I willingly yield to your desire, and I have good hope, that in fulfilling what you ask, I shall be useful too to many others, especially to those who are as yet novices in the real knowledge of Nature, and to those to whom the perplexities and the ordinary affairs of life leave but little leisure. Be careful then to seize on those precepts thoroughly, engrave them deeply in your memory, and meditate on them with the abridgment addressed to Herodotus, which I also send you.

Know then, that the only aim of the knowledge of the heavenly phenomena, both those which are spoken of in contact with one another, and of those which have a spontaneous existence, is that freedom from anxiety, and that calmness which is derived from a firm belief; and this is the aim of every other science.

It is not good to desire what is impossible, and to endeavor to enunciate a uniform theory about everything; accordingly, we ought not here to adopt the method, which we have followed in our researches into ethics, or in the solution of problems of natural philosophy. We there said, for instance, that there are no other things except bodies and the void, and that the atoms are the principles of things, and so the rest. In a word, we gave a precise and simple explanation for every fact, conformable to appearances.

We cannot act in the same way with respect to the heavenly phenomena.  These productions may depend upon several different causes, and we may give many different explanations on this subject, equally agreeing with the impression of the senses. Besides, it is not here a question about reasoning on new principles, and of laying down, à priori, rules for the interpretation of Nature.  The only guides for us to follow are the appearances themselves; for that which we have in view is not a set of systems and vain opinions, but much rather a life exempt from every kind disquietude.

The heavenly phenomena do not inspire those who give different explanations of them, conformable with appearances, instead of explaining them by hypothesis, with any alarm. But if, abandoning hypothesis, one at the same time renounces the attempt to explain them by means of analogies founded on appearances, then one is placing one’s self altogether at a distance from the science of Nature, in order to fall into fables.

It is possible that the heavenly phenomena may present some apparent characteristics which appear to assimilate them to those phenomena which we see taking place around ourselves, without there being any real analogy at the bottom. For the heavenly phenomena may depend for their production on many different causes.  Nevertheless, we must observe the appearances presented by each, and we must distinguish the different circumstances which attach to them, and which can be explained in different manners by means of analogous phenomena which arise under our eyes.

The world is a collection of things embraced by the heaven, containing the stars, the earth, and all visible objects. This collection, separated from the infinite, is terminated by an extremity, which is either rare, or dense, or revolving, or in a state of repose, or of a round, or triangular, or some shape or other in fact, for it may be any shape the dissolution of which must bring the destruction of everything which they embrace. In fact, it can take place in every sort of way, since there is not one of those things that are seen in this world which proves otherwise, and in which we cannot detect any extremity; and that such worlds are infinite in number is easily seen, and in the metakosmion, as we call the space between the worlds, being a huge space made up of matter and void, but not, as some philosophers pretend, an immensity of space absolutely empty. This production of a world may be explained thus: seeds suitably appropriated to such an end may emanate either from one or from several worlds, or from the space that separates them; they flow towards a particular point where they become collected together and organized; after that, other seeds come to unite them together in such a way as to form a durable whole, a basis, a nucleus to which all successive additions unite themselves.

One must not content one’s self in this question with saying, as one of the natural philosophers has done, that there is a reunion of the elements, or a violent motion in the void under the influence of necessity, and that the body which is thus produced increases until it come to crash against some other; for this doctrine is contrary to appearances.

The sun, the moon, and the other stars, were originally formed separately, and were afterwards comprehended in the entire total of the world. All the other objects which our world comprises, for instance, the earth and the sea, were also formed spontaneously, and subsequently gained size, by the addition and violent movement of light substances, composed of elements of fire and air, or even of these two principles at once. This explanation, moreover, is in accordance with the impressions of the senses.

As to the magnitude of the sun and of the other stars, it is, as far as we are concerned, such as it appears to us to be.  (This same doctrine is reproduced, and occurs again in the eleventh book of his treatise on Nature; where he says, “if the distance has made it lose is size, a fortiori, it would take away its brilliancy; for color has not, any more than size, the property of traversing distance without alteration.”)

But considered by itself, the sun may be a little greater or a little smaller than it appears; or it may be just such as it looks; for that is exactly the case with the fires of common occurrence among men, which are perceived by the senses at distance. Besides, all the difficulties on this subject will be easily explained if one attends to the clear evidence of the perceptions, as I have shown in my books about Nature.

The rising and setting of the sun, of the moon, and of the stars, may depend on the fact of their becoming lighted up, and extinguished alternately, and in the order which we behold. One may also give other reasons for the phenomenon, which are not contradicted by any sensible appearances; accordingly, one might explain them by the passage of the stars above and below the earth, for the impressions of the senses agree also with this supposition.

As to their motion, one may make that depend on the circular movement of the entire heaven. One may also suppose that the stars move, while the heaven itself is immovable; for there is nothing to prevent the idea that originally, before the formation of the world, they may have received, by the appointment of fate, an impulse from east to west, and that now their movement continues in consequence of their heat, as the fire naturally proceeds onwards in order to seek the nourishment which suits it.

The inter-tropical movements of the sun and moon may depend, either on the obliquity impressed by fate on the heaven at certain determined epochs, or on the resistance of the air, or on the fact that these ignited bodies stand in need of being nourished by a matter suitable to their Nature, and that this matter fails them; or finally, they may depend on the fact their having originally received an impulse which compels them to move as they do, describing a sort of spiral figure. The sensible evidence does not in the least contradict these different suppositions, and all those of the same kind which one can form, having always a due regard to what is possible, and can bring back each phenomenon to its analogous appearances in sensible facts, without disquieting one’s self about the miserable speculations of the astrologers.

The waning and subsequent replenishing of the moon may depend either on a conversion of this body, or on the different forms which the air when in a fiery state can adopt, or perhaps to the interposition of another body, or lastly, to some one of the causes by which one gives account of the analogous phenomena which pass under our eyes. Provided, however, that one does not obstinately adopt an exclusive mode of explanation; and that, for want of knowing what is possible for a man to explain, and what is inaccessible to his intelligence, one does not throw one’s self into interminable speculations.

It may also be possibly the case that the moon has a light of her own, or that she reflects that of the sun. For we see around us many objects which are luminous of themselves, and many other which have only a borrowed light. In a word, one will not be arrested by any of the celestial phenomena, provided that one always recollects that there are many explanations possible; that one examines the principles and reasons which agree with this mode of explanation, and that one does not proceed in accounting for the facts which do not agree with this method, to suffer one’s self to be foolishly carried away, and to propose a separate explanation for each phenomenon, sometimes in one way, and sometimes in another.

The appearance of a face in the orb of the moon, may depend either on a displacement of its parts, or on the interposition of some obstacle, or on any other cause capable of accounting for such an appearance.  For one must not neglect to apply this same method to all the heavenly phenomena; for, from the moment when one comes to any point of contradiction to the evidence of the senses, it will be impossible to posses perfect tranquility and happiness.

The eclipses of the sun and moon may depend either on the fact that these celestial bodies extinguish themselves, a phenomenon which we often see produced under our eyes, or on the fact of other bodies, the earth, the heaven, or something else of the same kind interposing, between them and us. Besides, we must compare the different modes of explanation appropriate to phenomena, and recollect that it is not impossible that many causes may at one and the same time concur in their production.  (He says the same thing in the twelfth book of his treatise on Nature; and adds that the eclipses of the sun arise from the fact that it penetrates into the shade of the moon, to quit it again presently; and the eclipse of the moon from the fact of its entering into the shade of the earth. We also find the same doctrine asserted by Diogenes, the Epicurean, in the first book of his Select Opinions.)

The regular and periodical march of these phenomena has nothing in it that ought to surprise us, if we only attend to the analogous facts which take place under our eyes. Above all things let us beware of making the Deity interpose here, for that being we ought to suppose exempt from all toil and perfectly happy; otherwise we shall be only giving vain explanations of the heavenly phenomena, as has happened already to a crowd of authors. Not being able to recognize what is really possible, they have fallen into vain theories, in supposing that for all phenomena there was but one single mode of production, and in rejecting all other explanations which are founded on probability.  They have adopted the most unreasonable opinions for want of placing in the front the study of heavenly phenomena, and of sensible facts, which ought to serve to explain the first.

The differences in the length of nights and days may arise from the fact that the passage of the sun above the earth is more or less rapid; and more or less slow, according to the length of the regions which it as to pass through. Or, again, to the fact certain regions are passed through more rapidly than others, as is seen to be the case by our own eyes, in those things to which we can compare the heavenly phenomena. As to those who on this point admit only one explanation as possible, they put themselves in opposition to facts, and lose sight of the bounds set to human knowledge.

The prognostics which are derived from the stars may, like those which we borrow from animals, arise from a simple coincidence. They may also have other causes, for example, some change in the air; for these two suppositions both harmonize equally with facts; but it is impossible to distinguish in what case one is to attribute them to the one cause or to the other.

The clouds may be formed either by the air condensed under the pressure of the winds, or by the agency of atoms set apart for the end, or by emanations from the earth and waters, or by other causes. For there are a great number which are all equally able to produce this effect. When the clouds clash with one another, or undergo any transformation, they produce showers; and the long rains are caused by the motion of the clouds when moved from places suitable to them through the air, when a more violent inundation than usual takes place, from collections of some masses calculated to produce these effects.

Thunder possibly arises from the movement of the winds revolving in the cavities of the clouds; of which we may see an image in vessels in our own daily use. It may also arise from the noise of fire acted upon by the wind in them, and from the tearings and ruptures of the clouds when they have received a sort of crystalline consistency. In a word, experience drawn from our sense, teaches us that all these phenomena, and that one in particular, may be produced in many different manners.

One may also assign different causes to lightning.  Either the shock and collision of the clouds produce a fiery appearance, which is followed by lightning; or the lighting up of the clouds by the winds, produces this luminous appearance; or the mutual pressure of the clouds, or that of the wind against them, disengages the lightning. Or, one might say, that the interception of the light diffused from the stars, arrested for a time in the bosom of the clouds, is driven from them subsequently by their own movements, and by those of the winds, and so escapes from their sides; that the lightning is an extremely subtle light that evaporates from the clouds; that the clouds which carry the thunder are collected masses of fire; that the lightning arises from the motion of the fire, or from the conflagration of the wind, in consequence of the rapidity and continuousness of its motion.  One may also attribute the luminous appearance of lightning to the rupture of the clouds under the action of the winds, or to the fall of inflammable atoms. Lastly, one may easily find a number of other explanations, if one applies to sensible facts, in order to search out the analogies which they present to the heavenly phenomena.

Lightning precedes thunder, either because it is produced at the same moment that the wind falls on the cloud, while the noise is only heard at the instant when the wind has penetrated into the bosom of the cloud.  Or, perhaps, the two phenomena being simultaneous, the lightning arrives among us more rapidly than the noise of the thunder-bolt, as is in fact remarked in other cases when we see at a instance the clash of two objects.

The thunderbolt may be produced either by a violent condensation of the winds, or by their rapid motion and conflagrations. It may arise from the fact of the winds meeting in places which are too dense, in consequence of the accumulation of clouds, and then a portion of the current detaches itself and proceeds towards the lower situations; or else it may be caused by the fire which is contained in the bosom of the clouds precipitating itself downwards. As one may suppose that an immense quantity of fire being accumulated in the clouds dilates, violently bursting the substance which envelops it, because the resistance of the center hinders it from proceeding further. This effect is especially produced in the neighborhood of high mountains; and, accordingly, they are very frequently struck with the thunderbolts.  In short, one may give a number of explanations of the thunderbolt; but we ought, above all things, to be on our guard against fables, and this one will easily be, if one follows faithfully the observable phenomena in the explanation of these things, which are not perceived, except indirectly.

Hurricanes may be caused either by the presence of a cloud, which a violent wind sets in motion and precipitates with a spiral movement towards the lower regions, or by a violent gust which bears a cloud into the neighborhood of some other current, or else by the mere agitation of the wind by itself, when air is brought together from the higher regions and compressed without being able to escape on either side, in consequence of the resistance of the air which surrounds it; when the hurricane descends towards the earth, then there result whirlwinds in proportion to the rapidity of the wind that has produced them; and this phenomenon extends over the sea also.

Earthquakes may arise from the wind penetrating into the interior of the earth, or from the earth itself receiving incessantly the addition of exterior particles, and being in incessant motion as to its constituent atoms, being in consequence disposed to a general vibration. That which permits the wind to penetrate is the fact that falls take place in the interior, or that the air being impressed by the winds insinuates itself into the subterranean caverns. The movement which numberless falls and the reaction of the earth communicates to the ground, when this motion meets bodies of greater resistance and solidity, is sufficient to explain the earthquakes.  One might, however, give an account of them in several other ways.

Winds are caused, either by the successive and regular addition of some foreign matter, or else by the reunion of a great quantity of water; and the differences of the winds may arise from the fact that some portions of this same matter fall into the numerous cavities of the earth, and are divided there.

Hail is produced by an energetic condensation acting on the ethereal particles which the cold embraces in every direction; or, in consequence of less violent condensation acting however on aqueous particles, and accompanied by division, in such a manner as to produce, at the same time, the reunion of certain elements and of the collective masses; or by the rupture of some dense and compact mass which would explain at the same time, the numerousness of the particles and their individual hardness. As to the spherical form of the hail, one may easily account for that by admitting that the shocks which it receives in every direction make all the angles disappear, or else that at the moment when the different fragments are formed, each of them is equally embraced on all sides by aqueous or ethereal particles.

Snow may be produced by a light vapor full of moisture which the clouds allow to escape by passage intended for that end, when they are pressed, in a corresponding manner, by other clouds, and set in motion by the wind. Subsequently, these vapors become condensed in their progress under the action of the cold which surrounds the clouds in the lower regions. It may also be the case that this phenomena is produced by clouds of slight density as they become condensed. In this case the snow which escapes from the clouds would be the result of the contact, or approximation of the aqueous particles, which in a still more condensed state produce hail.  This effect is most especially produced in the spring.  Snow again, may result from the collection of clouds previously condensed and solidified; or from a whole army of other causes.

Dew proceeds from a reunion of particles contained in the air calculated to produce this moist substance. These particles may be also brought from places which are moist or covered with water (for in those places, above all others, it is that dew is abundant). These then reunite, again resume their aqueous form, and fall down. The same phenomena takes place in other cases before our own eyes under many analogies.

Hoarfrost is dew congealed by the influence of the cold air that surrounds it.  Ice is formed either by the wearing away of round atoms contained in the water, and the reunion at scalene and acute angles of the atoms which exist in the water, or by an addition from without of these latter particles, which penetrating into the water, solidify it by driving away an equal amount of round atoms.

The rainbow may be produced by the reflection of the solar rays on the moist air; or it may arise from a particular property of light and air, in virtue of which these particular appearances of color are formed, either because the shades which we perceive result directly from this property, or because, on the contrary, it only produces a single shade, which, reflecting itself on the nearest portion of the air, communicates to them the tints which we observe. As to the circular form of the rainbow, that depends either on the fact of the sight perceiving an equal distance in every direction, or the fact of the atoms taking this form when reuniting in the air; or it may be caused by its detaching from the air which moves towards the moon, certain atoms which, being reunited in the clouds, give rise to this circular appearance.

The lunar halo arises from the fact of the air, which moves towards the moon from all quarters, uniformly intercepting the rays emitted by this heavenly object, in such a way as to form around it a sort of circular cloud which partially veils it. It may also arise from the fact of the moon uniformly rejecting from all quarters, the air which surrounds it, in such a manner as to produce this circular and opaque covering. And perhaps this opaqueness may be caused by some particle which some current brings from without; perhaps also, the heat communicates to the moon the property of emitting by the pores in its surface, the particles by which this effect is produced.

Comets arise either from the fact, that in the circumstances already stated, there are partial conflagrations in certain points of the heaven; or, that at certain periods, the heaven has above our heads a particular movement which causes them to appear. It may also be the case, that being themselves endowed with a peculiar movement, they advance at the end of certain periods of time, and in consequence of particular circumstances, towards the places which we inhabit. The opposite reasons explain their disappearance.

Certain stars return to the same point in accomplishing their revolutions; and this arises, not only as has been sometimes believed, from the fact of the pole of the world, around which they move, being immovable, but also from the fact that the gyrations of the air which surrounds them, hinder them from deviations like the wandering stars. Perhaps also, this may be caused by the fact, that except in the route in which they move, and in which we perceive them, they do not find any material suitable to their Nature. One may also explain this phenomenon in many other manners, reasoning according to observable facts; thus, it is possible that certain stars may be wandering because that is the Nature of their movements, and, for the same reason, others may be immovable.

It is also possible, that the same necessity which has originally given them their circular movement, may have compelled some to follow their orbit regularly, and have subjected others to an irregular process; we may also suppose that the uniform character of the center which certain stars traverse favors their regular march, and their return to a certain point; and that in the case of others, on the contrary, the differences of the center produce the changes which we observe. Besides, to assign one single cause to all these phenomena, when the experience of our senses suggests us several, is folly. It is the conduct of ignorant astrologers covetous of a vain knowledge, who assigning imaginary causes to facts, wish to leave wholly to the Deity the care of the government of the universe.

Some stars [the planets] appear to be left behind by others in their progress; this arises either from the fact of their having a slower motion, though traversing the same circle; or, because, though they are drawn on by the same propelling power, they have, nevertheless, a movement proper to themselves in a contrary direction; or it may be caused by the fact that, though all are placed in the same sphere of movement, still some have more space to traverse, and others less. To give one uniform and positive explanation of all these facts, is not consistent with the conduct of any people but those who love to flash prodigies in the eyes of the multitude.

Falling stars may be particles detached from the stars, or fragments resulting from their collision; they may also be produced by the fall of substances which are set on fire by the action of the wind; by the reunion of inflammable atoms which are made to come together so as to produce this effect by a sort of reciprocal attraction; or else by the movement which is produced in consequence of the reunion of atoms in the very place where they meet. It may also happen that the light vapors reunite and become condensed under the form of clouds, that they then take fire in consequence of their rotary motion, and that, bursting the obstacles which surround them, they proceed towards the places whither the force by which they are animated drags them. In short, this phenomenon also may admit a great number of explanations.

The forecasts which are drawn from certain animals arise from a fortuitous concourse of circumstances; for there is no necessary connection between certain animals and winter. They do not produce it; nor is there any divine Nature sitting aloft watching the exits of these animals, and then fulfilling signs of this kind.  Nor can such folly as this occur to any being who is even moderately comfortable, much less to one which is possessed of perfect happiness.

Imprint all these precepts in your memory, O Pythocles, and so you will easily escape fables, and it will be easy for you to discover other truths analogous to these. Above all, apply yourself to the study of general principles, of the infinite, and of questions of this kind, and to the investigation of the different criteria and of the passions, and to the study of the chief good, with a view to which we prosecute all our researches. When these questions are once resolved, all particular difficulties will be made plain to you. As to those who will not apply themselves to these principles, they will neither be able to give a good explanation of these same questions, nor to reach that end to which all our researches tend.

Such are his sentiments on the heavenly phenomena, But concerning the rules of life, and how we ought to choose some things, and avoid others, he writes thus. But first of all, let us go through the opinions which he held, and his disciples held, about the wise man.

The Wise Man Sayings

1.      Injuries are done among men either because of hatred, envy, or contempt, all which the wise man overcomes by reason.

2.      When once a man has attained wisdom he no longer has any contrary tendency to it, nor does he willingly pretend that he has.  He will be more deeply moved by feelings than others, but this will not prove to be an obstacle to wisdom.

3.      A man cannot become wise in every kind of physical constitution, or in every nation.

4.      Even if the wise man were to be put to torture, he would still be happy.

5.      The wise man shows gratitude, and constantly speaks well of his friends whether they are present or absent.

6.      The wise man will not groan and howl when he is put to the torture.

7.      The wise man will not have intercourse with any woman whom the laws forbid, as Diogenes says, in his epitome of the Ethical Maxims of Epicurus.

8.      The wise man will not punish his servants, but will rather pity them and forgive any that are deserving.

9.      The Epicureans do not think that the wise man will fall in love, or be anxious about his burial, for they hold that love is not a passion inspired by the gods, as Diogenes says in his twelfth book.

10.  The Epicureans assert that the wise man will not make elegant speeches.

11.  Sexual intercourse, the Epicureans say, has never done a man good, and he is lucky if it has not harmed him.

12.  The wise man will marry and have children, as Epicurus says in treatises On Problems and On Nature, but only in accord with the circumstances of his life.

13.  The wise man will never indulge in drunkenness, says Epicurus, in his Banquet,

14.  The wise man will not entangle himself in affairs of state, as Epicurus says in his first book on Lives.

15.  The wise man will not become a tyrant.

16.  The wise man will not live like a Cynic, as he says in his second book on Lives, nor become a beggar.

17.  Even if the wise man should lose his eyesight, he will not end his whole life, as he says in the same book.

18.  The wise man will not be subject to grief, as Diogenes says, in the fifth book of his Select Opinions.

19.  The wise man will not object to go to the courts of law.

20.  The wise man will leave books and memorials of himself behind him, but he will not be fond of frequenting assemblies.

21.  The wise man will take care of his property, and provide for the future.

22.  The wise man will be fond of the countryside.

23.  The wise man will resist fortune.

24.  The wise man will not mourn the death of his friends.

25.  The wise man will show a regard for his reputation to such an extent as to avoid being despised.

26.  The wise man will find more pleasure than other men in public spectacles.

27.  The wise man will erect statues of others, but he will be indifferent as to raising one for himself.

28.  The wise man is the only person who can converse correctly about music and poetry, but he will not himself compose poems.

29.  One wise man is not wiser than another.

30.  The wise man will also, if he is in need, earn money, but only by his wisdom.

31.  The wise man will appease an absolute ruler when occasion requires.

32.  The wise man will rejoice at another’s misfortune, but only for his correction.

33.  The wise man gather together a school, but never so as to become a leader of crowds.

34.  The wise man will give lectures in public, but it will be against his inclination and never unless asked.

35.  The wise man will teach things that are definite, rather than doubtful musings..

36.  The wise man be the same whether asleep or awake.

37.  The wise man will be willing even to die for a friend.

38.  The wise man holds that all faults are not of equal gravity.

39.  The wise man holds that health is a blessing to some, but a matter of indifference to others.

40.  The wise man holds that courage is a quality that does not come by nature, but by a consideration of what is to one’s advantage.

41.  The wise man holds that friendship is first brought about due to practical need, just as we sow the earth for crops, but it is formed and maintained by means of a community of life among those who find mutual pleasure in it.

42.  The wise man holds that there are two types of happiness – complete happiness, such as belongs to a god, which admits of no increase, and lesser happiness, which can be increased or decreased.


These are the Epicurean doctrines.

We must now proceed to his letter:

Letter to Menoeceus

Epicurus to Menoeceus, Greetings.

Let no one delay in the study of philosophy while he is young, and when he is old, let him not become weary of the study.  For no man can ever find the time unsuitable or too late to study the health of his soul.

And he who asserts either that it is too soon to study philosophy, or that the hour is passed, is like a man who would say that the time has not yet come to be happy, or that it is too late to be happy.

So both the young and the old must study philosophy  that as one grows old he may be young in the blessings that come from the grateful recollection of those good things that have passed, and that even in youth he may have the wisdom of age, since he will know no fear of what is to come.  It is necessary for us, then, to meditate on the things which produce happiness, since if happiness is present we have everything, and when happiness is absent we do everything with a view to possess it.

Now, I will repeat to you those things that I have constantly recommended to you, and I would have you do and practice them, as they are the elements of living well:

First of all, believe that a god is an incorruptible and happy being, just as Nature has commonly engraved on the minds of men.  But attach to your theology nothing which is inconsistent with incorruptibility or with happiness, and believe that a god possesses everything which is necessary to preserve its own nature.

Indeed the gods do exist, and Nature gives to us a degree of knowledge of them.  But gods are not of the character which most people attribute to them, and the conception of the gods held by most people is far from pure.  It is not the man who discards the gods believed in by the many who is impious, but he who applies to the gods the false opinions that most people entertain about them.  For the assertions of most people about the gods are not true intuitions given to them by Nature, but false opinions of their own, such as the idea that gods send misfortune to the wicked and blessings to the good.  False opinions such as these arise because men think of the gods as if they had human qualities, and men do not understand that the gods have virtues that are different from their own.

Next, accustom yourself to think that death is a matter with which we are not at all concerned.  This is because all good and all evil come to us through sensation, and death brings the end of all our sensations.  The correct understanding that death is no concern of ours allows us to take pleasure in our mortal lives, not because it adds to life an infinite span of time, but because it relieves us of the longing for immortality as a refuge from the fear of death.  For there can be nothing terrible in living for a man who rightly comprehends that there is nothing terrible in ceasing to live.

Seen in this way, it was a silly man who once said that he feared death, not because it would grieve him when it was present, but because it grieved him now to consider it to be coming in the future.  But it is absurd that something that does not distress a man when it is present should afflict him when it has not yet arrived. Therefore the most terrifying of fears, death, is nothing to us, since so long as we exist death is not present with us, and when death comes, then we no longer exist.  Death, then, is of no concern either to the living or to the dead – to the living, death has no existence, and to the dead, no concerns of any kind are possible.

Many people, however, flee from death as if it were the greatest of evils, while at other times these same people wish for death as a rest from the evils of life.  But the wise man embraces life, and he does not fear death, for life affords the opportunity for happiness, and the wise man does not consider the mere absence of life to be an evil.  Just as he chooses food not according to what is most abundant, but according to what is best; so too, the wise man does not seek to live the life that is the longest, but the happiest.

And so he who advises a young man to live well, and an old man to die well, is a simpleton, not only because life is desirable for both the young and the old, but also because the wisdom to live well is the same as the wisdom to die well.

Equally wrong was the man who said:

‘Tis well not to be born, but when born

Tis well to pass with quickness to the gates of Death.

If this was really his opinion, why then did he not end his own life? For it was easily in his power to do so, if this was really his belief. But if this man was joking, then he was talking foolishly in a case where foolishness ought not be allowed.

As to how we live our lives, we must always remember that the future does not wholly belong to us.  But on the other hand, the future does not wholly NOT belong to us either.  In this I mean that we can never wait on the future with a feeling of certainty that it will come to pass, but neither can we despair that the future is something that will never arrive.

We must also consider that some of our human desires are given to us by Nature, and some are vain and empty.  Of the Natural desires, some are necessary, and some are not.  Of the necessary desires, some are necessary to our happiness, and some are necessary if our body is to be free from trouble.  Some desires are in fact necessary for living itself.  He who has a correct understanding of these things will always decide what to choose and what to avoid by referring to the goal of obtaining a body that is healthy and a soul that is free from turmoil, since this is the aim of living happily.  It is for the sake of living happily that we do everything, as we wish to avoid grief and fear.  When once we have attained this goal, the storm of the soul is ended, because we neither have the need to go looking for something that we lack, nor to go seeking something else by which the good of our soul or of our body would be improved.

For you see when we lack pleasure and we grieve, we have need of pleasure, because pleasure is not present.  But so long as we do not grieve, life affords us no lack of pleasure.  On this account we affirm that Nature has provided that Pleasure is the beginning and end of living happily; for we have recognized that Nature has provided that happiness is the first good that is innate within us.  To this view of Happiness as our starting point and as our goal we refer every question of what to choose and what to avoid.  And to this same goal of happy living we again and again return, because whether a thing brings Happiness is the rule by which we judge every good.  But although happiness is the first and a natural good, for this same reason we do not choose every pleasure whatsoever, but at many times we pass over certain pleasures when difficulty is likely to ensue from choosing them.  Likewise, we think that certain pains are better than some pleasures, when a greater pleasure will follow them, even if we first endure pain for time.

Every Pleasure is therefore by its own Nature a good, but it does not follow that every pleasure is worthy of being chosen, just as every pain is an evil, and yet every pain must not be avoided.  Nature requires that we resolve all these matters by measuring and reasoning whether the ultimate result is suitable or unsuitable to bringing about a happy life; for at times we may determine that what appears to be good is in fact an evil, and at other times we may determine that what appears to be evil is in fact a good.

As we pursue happiness we also hold that self-reliance is a great good, not in order that we will always be satisfied with little, but in order that if circumstances do not allow that we have much, we may wisely make use of the little that we have.  This is because we are genuinely persuaded that men who are able to do without luxury are the best able to enjoy luxury when it is available.

We also believe that Nature provides that everything which is necessary to life is easily obtained, and that those things which are idle or vain are difficult to possess.  Simple flavors give as much pleasure as costly fare when everything that causes pain, and every feeling of want, is removed.  Bread and water give the most extreme pleasure when someone in great need eats of them. To accustom oneself, therefore, to simple and inexpensive habits is a great ingredient towards perfecting one’s health, and makes one free from hesitation in facing the necessary affairs of life. And when on certain occasions we fall in with more sumptuous fare, this attitude renders us better disposed towards luxuries, as we are then fearless with regard to the possibility that we may thereafter lose them.

When, therefore, we say that pleasure or happiness is the chief good, we are not speaking of the pleasures of debauched men, or those pleasures which lie in sensual enjoyment, as some allege about us who are ignorant, or who disagree with us, or who perversely misrepresent our opinions.  Instead, when we speak of pleasure or happiness as the chief good, we mean the freedom of the body from pain and the freedom of the soul from confusion.  For it is not continued drinking and reveling, or the temporary pleasures of sexual relations, or feasts of fish or such other things as a costly table supplies that make life pleasant.  Instead, Nature provides that life is made pleasant by sober contemplation, and by close examination of the reasons for all decisions we make as to what we choose and what we avoid.  It is by these means that we put to flight the vain opinions from which arise the greater part of the confusion that troubles the soul.

Now, the beginning and the greatest good of all these things is wisdom.  Wisdom is something more valuable even than philosophy itself, inasmuch as all the other virtues spring from it.  Wisdom teaches us that it is not possible to live happily unless one also lives wisely, and honestly, and justly; and that one cannot live wisely and honestly and justly without also living happily.  For these virtues are by nature bound up together with the happy life, and the happy life is inseparable from these virtues.

Considering this, who can you think to be a better man than he who has holy opinions about the gods, who is utterly fearless in facing death, who properly contemplates the goals and limits of life as fixed by Nature, and who understands that Nature has established that the greatest goods are readily experienced and easily obtained, while the greatest evils last but a short period and cause only brief pain?

The wise man laughs at the idea of “Fate”, which some set up as the mistress of all things, because the wise man understands that while some things do happen by chance, most things happen due to our own actions.  The wise man sees that Fate or Necessity cannot exist if men are truly free, and he also sees that Fortune is not in constant control of the lives of men.  But the wise man sees that our actions are free, and because they are free, our actions are our own responsibility, and we deserve either blame or praise for them.

It would therefore be better to believe in the fables that are told about the gods than to be a slave to the idea of Fate or Necessity as put forth by false philosophers. At least the fables which are told about the gods hold out to us the possibility that we may avert the gods’ wrath by paying them honor.  The false philosophers, on the other hand, present us with no hope of control over our own lives, and no escape from an inexorable Fate.

In the same way, the wise man does not consider Fortune to be a goddess, as some men esteem her to be, for the wise man knows that nothing is done at random by a god. Nor does he consider that such randomness as may exist renders all events of life impossible to predict.  Likewise, he does not believe that the gods give chance events to men so as to make them live happily.  The wise man understands that while chance may lead to great good, it may also lead to great evil, and he therefore thinks it to be better to be unsuccessful when acting in accord with reason than to be successful by chance when acting as a fool.

Meditate then, on all these things, and on those things which are related to them, both day and night, and both alone and with like-minded companions.  For if you will do this, you will never be disturbed while asleep or awake by imagined fears, but you will live like a god among men.  For a man who lives among immortal blessings is in no respect like a mortal being.

(In other works, he discards divination; and also in his Little Epitome. And he says divination has no existence; but, if it has any, still we should think that what happens according to it is nothing to us.)

These are his sentiments about the things which concern the life of man, and he has discussed them at greater length elsewhere.

Now, he differs from the Cyrenaics about pleasure. For they do not admit that to pleasure can exist as a state, but place it wholly in motion. He, however, admits both kinds to be pleasure, namely, that of the soul, and that of the body, as he says in his treatise on Choice and Avoidance; and also in his work on the Chief Good; and in the first book of his treatise on Lives, and in his Letter against the Mitylenian Philosophers. And in the same spirit, Diogenes, in the seventeenth book of his Select Discourses, and Metrodorus, in his Timocrates, speak thus. “But when pleasure is understood, I mean both that which exists in motion, and that which is a state….” And Epicurus, in his treatise on Choice, speaks thus: “Now, freedom from disquietude, and freedom from pain, are states of pleasure; but joy and cheerfulness are beheld in motion and energy.”

For the Cyrenaics make out the pains of the body to be worse than those of the mind; accordingly, those who do wrong, are punished in the body. But he considers the pains of the soul the worst; for that the flesh is only sensible to present affliction, but the soul feels the past, the present, and the future. Therefore, in the same manner, he contends that the pleasure of the soul are greater than those of the body; and he uses as proof that pleasure is the chief good, the fact that all animals from the moment of their birth are delighted with pleasure, and are offended with pain by their natural instinct, and without the employment of Reason. Therefore, too we, of our own inclinations, flee from pain; so that Heracles, when devoured by his poisoned tunic cries out:

Shouting and groaning, and the rocks around

Re-echoed his sad wails, the mountain heights

Of Locrian lands, and sad Euboea’s hills.


And we choose the virtues for the sake of pleasure, and not on their own account; just as we seek the skill of the physician for the sake of health, as Diogenes says, in the twentieth book of his Select Discourses, where he also calls out that virtue alone is inseparable from pleasure, but that every thing else may be separated from it as mortal.

Let us, however, now add the finishing stroke, as one may say, to this whole treatise, and to the life of the philosopher; giving some of his fundamental maxims, and closing the whole work with them, taking that for our end which is the beginning of happiness.

The Principal Doctrines 

1.      That which is happy and imperishable, neither has trouble itself, nor does it cause it to anything; so that it is not subject to feelings of either anger or gratitude; for these feelings exist only in what is weak.[vi]

2.      Death is nothing to us; for that which is dissolved is devoid of sensation, and that which is devoid of sensation is nothing to us.

3.      The limit of great pleasures is the removal of everything which can give pain. And where pleasure is, as long as it lasts, that which gives pain, or that which feels pain, or both of them, are absent.

4.      Pain does not abide continuously in the flesh, but in its extremity it is present only a very short time. That pain which only just exceeds the pleasure in the flesh, does not last many days. But long diseases have in them more that is pleasant than painful to the flesh.

5.      It is not possible to live pleasantly without living prudently, and honorably, and justly; nor to live prudently, and honorably, and justly, without living pleasantly. But to whom it does not happen to live prudently, honorably, and justly cannot possibly live pleasantly.

6.      For the sake of feeling confidence and security with regard to men, anything in Nature is good, if it provides the means to achieve this.

7.      Some men have wished to be eminent and powerful, thinking that so they would secure safety as far as men are concerned. So that if the life of such men is safe, they have attained to the Nature of good; but if it is not safe, then they have failed in obtaining that for the sake of which they originally desired power according to the order of Nature.[vii]

8.      No pleasure is intrinsically bad: but the effective causes of some pleasures bring with them a great many perturbations of pleasure.

9.      If every pleasure were condensed, if one may so say, and if each lasted long, and affected the whole body, or the essential parts of it, then there would be no difference between one pleasure and another.

10.  If those things which make the pleasures of debauched men, put an end to the fears of the mind, and to those which arise about the heavenly bodies, and death, and pain; and if they taught us what ought to be the limit of our desires, we should have no pretense for blaming those who wholly devote themselves to pleasure, and who never feel any pain or grief (which is the chief evil) from any quarter.

11.  If apprehensions relating to the heavenly bodies did not disturb us, and if the terrors of death have no concern with us, and if we had the courage to contemplate the boundaries of pain and of the desires, we should have no need of the study of natural science.

12.  It would not be possible for a person to banish all fear about those things which are called most essential, unless he knew what is the Nature of the universe, or if he had any idea that the fables told about it could be true; and therefore a person cannot enjoy unmixed pleasure without physiological knowledge.

13.  It would be no good for a man to secure himself safety as far as men are concerned, while in a state of apprehension as to all the heavenly bodies, and those under the earth, and in short, all those in the infinite.

14.  Irresistible power and great wealth may, up to a certain point, give us security as far as men are concerned; but the security of men in general depends upon the tranquility of their souls, and their freedom from ambition.

15.  The riches of Nature are defined and easily procurable; but vain desires are insatiable.

16.  The wise man is but little favored by fortune; but his reason procures him the greatest and most valuable goods, and these he does enjoy, and will enjoy the whole of his life.

17.  The just man is the freest of all men from disquietude; but the unjust man is a perpetual prey to it.

18.  Pleasure in the flesh is not increased, when once the pain arising from want is removed; it is only diversified. The most perfect happiness of the soul depends on these reflections, and on opinions of a similar character on all those questions which cause the greatest alarm to the mind.

19.  Infinite and finite time both have equal pleasure, if any one measures its limits by reason.

20.  The flesh sets no limits to pleasure, and therefore it yearns for an eternity of time. But reason, enabling us to conceive the end and dissolution of the body, and liberating us from the fears relative to eternity, procures for us all the happiness of which life is capable, so completely that we have no further occasion to include eternity in our desires. In this disposition of mind, man is happy even when his troubles engage him to quit life; and to die thus, is for him only to interrupt a life of happiness.

21.  He who is acquainted with the limits of life knows that that which removes the pain which arises from want and which makes the whole of life perfect, is easily procurable; so that he has no need of those things which can only be attained with trouble.

22.  But as to the ultimate aim, we ought to consider it with all the clearness and evidence which we refer to whatever we think and believe; otherwise, all things will be full of confusion and uncertainty of judgment.

23.  If you resist all the senses, you will not even have anything left to which you can refer, or by which you may be able to judge of the falsehood of the senses which you condemn.

24.  If you simply discard a sense, and do not distinguish between the different elements of the judgment, so as to know on the one hand, the opinion which goes beyond the actual sensation, or, on the other, the actual and immediate notion, the affections, and all the conceptions of the mind which arise from the observable representation; you will be imputing trouble into the other senses, and destroying in that quarter every species of criterion. 

25.  If you allow equal authority to the ideas, which being only an opinion, require to be verified, and to those which bear about them an immediate certainty, you will not escape error; for you will be confounding doubtful opinions with those which are not doubtful, and true judgments with those of a different character.

26.  If, on every occasion, we do not refer every one of our actions to the chief end of Nature, if we turn aside from that to seek or avoid some other object, there will be a want of agreement between our words and our actions.

27.  Of all the things which wisdom provides for the happiness of the whole life, by far the most important is the acquisition of friendship.

28.  The same opinion encourages man to trust that no evil will be everlasting, or even of long duration; as it sees that, in the space of life allotted to us, the protection of friendship is most sure and trustworthy.

29.  Of the desires, some are natural and necessary, some natural, but not necessary, and some are neither natural nor necessary, but owe their existence to vain opinions. (Epicurus thinks that those are natural and necessary which put an end to pains as drink when one is thirsty; and that those are natural but not necessary which only diversify pleasure, but do not remove pain, such as expensive food; and that these are neither natural nor necessary, which are such as crowns, or the erection of statues.)

30.  All desires that lead to no pain when they remain ungratified are unnecessary, and the longing is easily got rid of, when the thing desired is difficult to procure or when the desires seem likely to produce harm.  When those natural desires, which do not lead to pain if they are not satisfied, are violent and insistent, it is a proof that there is an admixture of vain opinion in them; for then energy does not arise from their own Nature, but from the vain opinions of men.

31.  Natural justice is a covenant of what is suitable for leading men to avoid injuring on another, and being injured.

32.  Those animals which are unable to enter into an argument of this Nature, or to guard against doing or sustaining mutual injury, have no such thing as justice or injustice. And the case is the same with those nations, the members of which are either unwilling or unable to enter into a covenant to respect their mutual interests.

33.  Justice has no independent existence; it results from mutual contracts, and establishes itself wherever there is a mutual engagement to guard against doing or sustaining mutual injury.

34.  Injustice is not intrinsically bad; it has this character only because there is joined with it a fear of not escaping those who are appointed to punish actions of this character.

35.  It is not possible for a man who secretly does anything in contravention of the agreement which men have made with one another, to guard against doing, or sustaining mutual injury, to believe that he shall always escape notice, even if he has escaped notice already ten thousand times; for till his death, it is uncertain whether he will not be detected.

36.  In a general point of view, justice is the same thing to every one; for there is something advantageous in mutual society. Nevertheless, the difference of place, and diverse other circumstances, make justice vary.

37.  From the moment that a thing declared just by the law is generally recognized as useful for the mutual relations of men, it becomes really just, whether it is universally regarded as such or not. But if, on the contrary, a thing established by law is not really useful for social relations, then it is not just; and if that which was just, inasmuch as it was useful, loses this character, after having been for some time considered so, it is not less true that during that time it was really just, at least for those who do not perplex themselves about vain words, but who prefer in every case, examining and judging for themselves.

38.  When, without any fresh circumstances arising a thing which has been declared just in practice does not agree with the impressions of reason, that is a proof that the thing was not really just. In the same way, when in consequence of new circumstances, a thing which has been pronounced just does not any longer appear to agree with utility, the thing which was just, inasmuch as it was useful to the social relations and intercourse of mankind, ceases to be just the moment when it ceases to be useful.

39.  He who desires to live tranquilly without having anything to fear from other men, ought to make himself friends; those whom he cannot make friends of, he should, at least avoid rendering enemies; and if that is not in his power, he should, as far as possible, avoid all intercourse with them, and keep them aloof, as far as it is for his interest to do so.

40.  The happiest men are they who have arrived at the point of having nothing to fear from those who surround them. Such men live with one another most agreeably, having the firmest grounds of confidence in one another, enjoying the advantages of friendship in all their fullness, and not lamenting as a pitiable circumstance, the premature death of their friends.



[i] (And Epicurus establishes the same principles at the beginning of the Great Abridgment; and in the first book of his treatise on Nature.)

[ii] (The same principles are laid down in the first, and fourteenth, and fifteenth book of the treatise on Nature; and also in the Great Abridgment.)

[iii] (Epicurus adds, a little lower down, that divisibility, ad infinitum, is impossible; for says he, the only things which change are the qualities; unless, indeed one wishes to proceed from division to division, till one arrives absolutely at infinite smallness.)

[iv] (He says, farther on, that they move with an equal rapidity from all eternity, since the void offers no more resistance to the lightest than it does to the heaviest.)

[v] (He says, further on, that the atoms have no peculiar quality of their own, except from magnitude and weight. As to color, he says in the twelfth book of his Principia, that it varies according to the position of the atoms. Moreover, he does not attribute to the atoms any kind of dimensions; and accordingly, no atom has ever been perceived by the senses; but this expression, if people only recollect what is here said, will by itself offer to the thoughts a sufficient image of the Nature of things.)

[vi] (In other passages he says that the gods are speculated on by reason, some existing according to number, and others according to some similarity of form, arising from the continual flowing on of similar images, perfected for this very purpose in human form.)

[vii] The text of this doctrine appears to be corrupted, for its meaning is not clear, nor is it clear whether this portion is one or two doctrines.  Yonge separates these; we combine them here is an effort to attain greater clarity.