The purpose of this page is to highlight several of the most key sections in the Epicurean literature on the issue of “correct thinking.”
Commentary will be added here later, but to start, here are several key citations from Lucretius’ De Rerum Natura, followed by the most relevant Authorized Doctrines. Be sure to refer also to Philodemus’ On Methods of Inference from the Herculaneum scrolls, as translated by De Lacy.
Excerpt 1, From Lucretius’ Book I
(Humphries Translation on Left; Munro Translation on Right)
Now to repeat: The nature of everything is dual – matter And void; or particles and space, wherein The former rest or move. We have our senses To tell us matter exists. Denying this, We cannot, searching after hidden things, Find any base of reason whatsoever. Next, if there is no place, or space, our so-called void, Bodies could nowhere be, and nowhere move. I proved this not so long ago, remember. Also, there’s nothing else which you can call Distinct alike from matter and from void, Some kind of, maybe, third alternative. No. What exists is something in itself, Susceptible to touch, however frail, However tiny, and capable of growth, Of increase after its fashion. But a something Touch cannot reach, a thing that cannot keep Another thing from simply passing through it, This kind of thing must be our so-called void. Besides, if something has its own existence, It will either act itself, or, being passive, Will suffer other things to act upon it, Or yield a space where things can be, or happen, But nothing without substance has the power to act, or to be acted on, and nothing Can proffer space except the void and empty. Therefore, except for void and substance, nothing, No third alternative, no other nature Can possibly exist in the sum of things, Perceptible to any of our senses Or apprehended by the reasoning mind.
But now to resume the thread of the design which I am weaving in verse: all nature then, as it exists by itself, is founded on two things: there are bodies and there is void in which these bodies are placed and through which they move about. For that body exists by itself the general feeling of man kind declares; and unless at the very first belief in this be firmly grounded, there will be nothing to which we can appeal on hidden things in order to prove anything by reasoning of mind. Then again, if room and space which we call void did not exist, bodies could not be placed anywhere nor move about at all to any side; as we have demonstrated to you a little before. Moreover there is nothing which you can affirm to be at once separate from all body and quite distinct from void, which would so to say count as the discovery of a third nature. For whatever shall exist, this of itself must be something or other. Now if it shall admit of touch in however slight and small a measure, it will, be it with a large or be it with a little addition, provided it do exist, increase the amount of body and join the sum. But if it shall be intangible and unable to hinder any thing from passing through it on any side, this you are to know will be that which we call empty void. Again whatever shall exist by itself, will either do something or will itself suffer by the action of other things, or will be of such a nature as things are able to exist and go on in. But no thing can do and suffer without body, nor aught furnish room except void and vacancy. Therefore beside void and bodies no third nature taken by itself can be left in the number of things, either such as to fall at any time under the ken of our senses or such as any one can grasp by the reason of his mind.
Excerpt 2, from Lucretius’ Book Four
(Humphries Translation on Left; Munro Translation on Right)
Oh, there are Many examples of illusion’s craft Whereby we are beguiled to doubt our senses. A vain endeavor, really; on the whole, We are fooled, or fool ourselves, because we bring Such predilections with us that we see Imagined things, not real ones. Humankind Finds nothing harder than to separate The patent facts from those dubieties Mind loves to introduce. But if a man Argues that, therefore, nothing can be known, He does not really even know that much Since he’s confessing total ignorance. I’d best not argue with this kind of man Who sticks his head in the ground, his feet in the air. Still, let me grant he knows this much, I’ll ask How, since he’s never caught one glimpse of truth In anything whatever, how does he know What knowing and non-knowing are, what fact Gave him the notion of the true and false, Assured him of a difference between The doubtful and the certain? You will find All knowledge of the truth originates Out of the senses, and the senses are Quite irrefutable. Find, if you can, A standard more acceptable than sense To sort out truth from falsehood. What can be More credible than sense? Shall reasoning, Born of some error, some delusionment, Argue the senses down? Ridiculous! If sense is false, reason will have to be. Can ears refute the eyes, the sense of touch Negate the sense of hearing? Do our noses Appeal against our eyes, our sense of taste File counterclaim against our ears’ report? I’d hardly think so. To each sense belongs Its jurisdiction, so that soft, hot, cold, Color, sound, shape, and odor are assigned To different areas. Therefore, no sense Can contradict another or itself, Since their report must be dependable The same way always. If at any time A thing seems true to them, it must be so. And if your reasoning faculties can find No explanation why a thing looks square When seen close up, and round when farther off, Even so, it might be better for a man Who lacks the power of reason, to give out Some idiotic theory, than to drop All hold of basic principles, break down Every foundation, tear apart the frame That holds our lives, our welfare. All is lost, Not only reason, but our very life, Unless we have the courage and the nerve To trust the senses, to avoid those sheer Downfalls into the pits and tarns of nonsense. All that verbose harangue against the senses Is utter absolute nothing. If a building Were planned by someone with a crooked ruler Or an inaccurate square, or spirit-level A little out of true, the edifice, In consequence, would be a frightful mess, Warped, wobbly, wish-wash, weak and wavering, Waiting a welter of complete collapse – So let your rule of reason never be Distorted by the fallacies of sense Lest all your logic prove a road to ruin.
Many are the other marvels of this sort we see, which all seek to shake as it were the credit of the senses: quite in vain, since the greatest part of these cases cheats us on account of the mental suppositions which we add of ourselves, taking those things as seen which have not been seen by the senses. For nothing is harder than to separate manifest facts from doubtful which straightway the mind adds on of itself. Again if a man believe that nothing is known, he knows not whether this even can be known, since he admits he knows nothing. I will therefore decline to argue the case against him who places himself with head where his feet should be. And yet granting that he knows this, I would still put this question, since he has never yet seen any truth in things, whence he knows what knowing and not knowing severally are, and what it is that has produced the knowledge of the true and the false and what has proved the doubtful to differ from the certain. You will find that from the senses first has proceeded the knowledge of the true and the false and that the senses cannot be refuted. For that which is of itself to be able to refute things false by true things must from the nature of the case be proved to have the higher certainty. Well then, what must fairly be accounted of higher certainty than sense? Shall reason founded on false sense be able to contradict them, wholly founded as it is on the senses? And if they are not true, then all reason as well is rendered false. Or shall the ears be able to take the eyes to task, or the touch the ears? Again shall the taste call in question this touch, or the nostrils refute or the eyes controvert it? Not so, I guess; for each apart has its own distinct office, each its own power; and therefore we must perceive what is soft and cold or hot by one distinct faculty, by another perceive the different colors of things and thus see all objects which are conjoined with color. Taste too has its faculty apart; smells spring from one source, sounds from another. It must follow therefore that any one sense cannot confute any other. No nor can any sense take itself to task, since equal credit must be assigned to it at all times. What therefore has at any time appeared true to each sense, is true. And if reason shall be unable to explain away the cause why things which close at hand were square, at a distance looked round, it yet is better, if you are at a loss for the reason, to state erroneously the causes of each shape than to let slip from your grasp on any side things manifest and ruin the groundwork of belief and wrench up all the foundations on which rest life and existence. For not only would all reason give way, life itself would at once fall to the ground, unless you choose to trust the senses and shun precipices and all things else of this sort that are to be avoided, and to pursue the opposite things. All that host of words then be sure is quite unmeaning which has been drawn out in array against the senses. Once more, as in a building, if the rule first applied is wry, and the square is untrue and swerves from its straight lines, and if there is the slightest hitch in any part of the level, all the construction must be faulty, all must be wry, crooked, sloping, leaning forwards, leaning backwards, without symmetry, so that some parts seem ready to fall, others do fall, ruined all by the first erroneous measurements; so too all reason of things must needs prove to you distorted and false, which is founded on false senses.
Excerpt 3, From Lucretius’ Book VI
(Humphries Translation on Left; Munro Translation on Right)
Athens of bright renown was first to bring The gift of grain to troubled humankind, Gave new vitality, established laws, And first made life more than endurable; She blessed in the sweetness of her boon a man Who told the truth completely, so endowed That now beyond his death his glory seems Almost divine, exalted to the stars. For when he saw that mortals on this earth Had all or nearly all that need requires, Security almost complete, were rich, Were powerful, were honored, and were proud Of their sons’ recognition and renown, And yet at home each had an anxious heart – Life was one long vexation, never a pause, No let-up in the daily cries of rage, Of passionate complaining. So there must, He knew, be some corruption in the jar, The vase, the vessel of life – enough to spoil Whatever good came through it from without. Either it leaked, impossible to fill, Or stank and fouled its contents. So he cleansed Our hearts by words of truth; he put an end To greeds and fears; he showed the highest good Toward which we all are aiming, showed the way, A straight and narrow path; he taught, besides, What evils every here and there confront The lives of men; how this is natural As well as manifold, and may occur By chance or violent intent, in line With nature’s preparations; but her drives, Her onslaughts, can be baffled, once we learn The proper sally ports to counter from. He proved that it was mostly vain and wrong For human hearts to suffer tides of troubles, Inflict anxiety upon themselves; And just as children, fearing everything, Tremble in darkness, we, in the full light, Fear things that really are not one bit more awful Than what poor babies shudder at in darkness, The horrors they imagine to be coming. Our terrors and our darknesses of mind Must be dispelled, then, not by sunshine’s rays But by insight into nature and a scheme Of systematic study.
IN days of yore Athens of famous name first imparted corn-producing crops to suffering mankind, and modeled life anew and passed laws; and first too bestowed sweet solaces of existence, when she gave birth to a man who showed himself gifted with such a genius and poured forth all knowledge of old from his truth-telling mouth; whose glory, even now that he is dead, on account of his godlike discoveries confirmed by length of time is spread abroad among men and reaches high as heaven. For when he saw that the things which their needs imperiously demand for subsistence had all without exception been already provided for men, and that life, so far as was possible, was placed on a sure footing, that men were great in affluence of riches and honors and glory and swelled with pride in the high reputation of their children, and yet that none of them at home for all that had a heart the less disquieted, and that this heart in despite of the understanding plagued life without any respite and was constrained to rave with distressful complainings, he then perceived that the vessel itself did cause the corruption and that by its corruption all the things that came into it and were gathered from abroad, however salutary were spoilt within it; partly because he saw it to be leaky and full of holes so that it could never by any means be filled full; partly because he perceived that it befouled so to say with a nauseous flavor everything within it which it had taken in. He therefore cleansed men’s breasts with truth-telling precepts and fixed a limit to lust and fear and explained what was the chief good which we all strive to reach, and pointed out the road along which by a short cross-track we might arrive at it in a straightforward course; he showed too what evils existed in mortal affairs throughout, rising up and manifoldly flying about by a natural –call it chance or force, because nature had so brought it about – and from what gates you must sally out duly to encounter each; and he proved that mankind mostly without cause arouse in their breast the melancholy tumbling billows of cares. For even as children are flurried and dread all things in the thick darkness, thus we in the daylight fear at times things not a whit more to be dreaded than what children shudder at in the dark and fancy sure to be. This terror therefore and darkness of mind must be dispelled, not by the rays of the sun and glittering shafts of day, but by the aspect and law of nature.
22. We must consider both the ultimate end and all clear sensory evidence, to which we refer our opinions; for otherwise everything will be full of uncertainty and confusion.
23. If you fight against all your sensations, you will have no standard to which to refer, and thus no means of judging even those sensations which you claim are false.
24. If you reject absolutely any single sensation without stopping to distinguish between opinion about things awaiting confirmation and that which is already confirmed to be present, whether in sensation or in feelings or in any application of intellect to the presentations, you will confuse the rest of your sensations by your groundless opinion and so you will reject every standard of truth. If in your ideas based upon opinion you hastily affirm as true all that awaits confirmation as well as that which does not, you will not avoid error, as you will be maintaining the entire basis for doubt in every judgment between correct and incorrect opinion.
25. If you do not on every occasion refer each of your actions to the ultimate end prescribed by nature, but instead of this in the act of choice or avoidance turn to some other end, your actions will not be consistent with your theories.