I am aware of three instances documented in the core ancient texts where the students of Epicurus divereged from his teachings. These three issues, along with the documentation, are as follows. When you consider all these together, do you see any common thread?
1 – Is the fact that pleasure is desirable and pain to be avoided something that should be proved by logic/reason?
Cicero – “On Ends”: Epicurus refuses to admit any necessity for argument or discussion to prove that pleasure is desirable and pain to be avoided. These facts, be thinks, are perceived by the senses, as that fire is hot, snow white, honey sweet, none of which things need be proved by elaborate argument: it is enough merely to draw attention to them. (For there is a difference, he holds, between formal syllogistic proof of a thing and a mere notice or reminder: the former is the method for discovering abstruse and recondite truths, the latter for indicating facts that are obvious and evident.) Strip mankind of sensation, and nothing remains; it follows that Nature herself is the judge of that which is in accordance with or contrary to nature. What does Nature perceive or what does she judge of, beside pleasure and pain, to guide her actions of desire and of avoidance?
Some members of our school however would refine upon this doctrine; these say that it is not enough for the judgment of good and evil to rest with the senses; the facts that pleasure is in and for itself desirable and pain in and for itself to be avoided can also be grasped by the intellect and the reason. Accordingly they declare that the perception that the one is to be sought after and the other avoided is a notion naturally implanted in our minds. Others again, with whom I agree, observing that a great many philosophers do advance a vast array of reasons to prove why pleasure should not be counted as a good nor pain as an evil, consider that we had better not be too confident of our case; in their view it requires elaborate and reasoned argument, and abstruse theoretical discussion of the nature of pleasure and pain.
2 – Is there a necessity to justify friendship beyond what Epicurus said (That friendship is the greatest means to happiness)?
Cicero – “On Ends”: Now Epicurus’s pronouncement about friendship is that of all the means to happiness that wisdom has devised, none is greater, none more fruitful, none more delightful than this. Nor did he only commend this doctrine by his eloquence, but far more by the example of his life and conduct. How great a thing such friendship is, is shown by the mythical stories of antiquity. Review the legends from the remotest ages, and, copious and varied as they are, you will barely find in them three pairs of friends, beginning with Theseus and ending with Orestes. Yet Epicurus in a single house and that a small one maintained a whole company of friends, united by the closest sympathy and affection; and this still goes on in the Epicurean school.
But to return to our subject, for there is no need of personal instances: I notice that the topic of friendship has been treated by Epicureans in three ways:
(A) Some have denied that pleasures affecting our friends are in themselves to be desired by us in the same degree as we desire our own pleasures. This doctrine is thought by some critics to undermine the foundations of friendship; however, its supporters defend their position, and in my opinion have no difficulty in making good their ground. They argue that friendship can no more be sundered from pleasure than can the virtues, which we have discussed already. A solitary, friendless life must be beset by secret dangers and alarms. Hence reason itself advises the acquisition of friends; their possession gives confidence, and a firmly rooted hope of winning pleasure. And just as hatred, jealousy, and contempt are hindrances to pleasure, so friendship is the most trustworthy preserver and also creator of pleasure alike for our friends and for ourselves. It affords us enjoyment in the present, and it inspires us with hopes for the near and distant future.
Thus it is not possible to secure uninterrupted gratification in life without friendship, nor yet to preserve friendship itself unless we love our friends as much as ourselves. Hence this unselfishness does occur in friendship, while also friendship is closely linked with pleasure. For we rejoice in our friends’ joy as much as in our own, and are equally pained by their sorrows. Therefore the Wise Man will feel exactly the same towards his friend as he does towards himself, and will exert himself as much for his friend’s pleasure as he would for his own. All that has been said about the essential connection of the virtues with pleasure must be repeated about friendship. Epicurus well said (I give almost his exact words): “The same creed that has given us courage to overcome all fear of everlasting or long-enduring evil hereafter, has discerned that friendship is our strongest safeguard in this present term of life.”
(B) Other Epicureans though by no means lacking in insight are a little less courageous in defying the opprobrious criticisms of the Academy. They fear that if we hold friendship to be desirable only for the pleasure that it affords to ourselves, it will be thought that it is crippled altogether. They therefore say that the first advances and overtures, and the original inclination to form an attachment, are prompted by the desire for pleasure, but that when the progress of intercourse has led to intimacy, the relationship blossoms into an affection strong enough to make us love our friends for their own sake, even though no practical advantage accrues from their friendship, Does not familiarity endear to us localities, temples, cities, gymnasia, and playing-grounds, horses and hounds, gladiatorial shows and fights with wild beasts, then how much more natural and reasonable that this should be able to happen in our intercourse with our fellow-men!
(C) The third view is that wise men have made a sort of compact to love their friends no less than themselves. We can understand the possibility of this, and we often see it happen. Clearly no more effective means to happiness could be found than such an alliance.
(3) How many standards of truth are there – three or four?
Diogenes Laertius: “Now in The Canon Epicurus affirms that our sensations and preconceptions and our feelings are the standards of truth; the Epicureans generally make perceptions of mental presentations to be also standards. His own statements are also to be found in the Summary addressed to Herodotus and in the Principal Doctrines.”
3 – Are there three criteria of truth, or four?