Plato ostensibly devotes an entire book, the Lysis, to defining friendship or philia, which he is reluctant to distinguish from erotic love or erôs. In the Lysis, Socrates is in conversation with two youths, Lysis and Menexenus. Socrates tells the youths that, whereas some people desire horses, or dogs, or gold, or honour, he would rather have a good friend than ‘the best cock or quail in the world’: ‘Yea, by the dog of Egypt, I should greatly prefer a real friend to all the gold of Darius, or even to Darius himself: I am such a lover of friends as that’. Lysis and Menexenus appear to possess this treasure in each other, so perhaps Menexenus can tell him: when one person loves another, which of the two becomes the friend of the other, the lover or the beloved? Menexenus replies that either may be the friend of the other, that is, they both are friends. Socrates says that this cannot be the case, since one person may love another who does not love him back, or even who hates him. Menexenus suggests that, unless they both love each other, neither is a friend. Socrates disagrees, and explains that if something that does not love in return is not beloved by a lover, then there can be no lovers of things such as horses, dogs, wine, or wisdom. Thus, what is beloved, whether or not it loves in return, may be dear to the lover of it. Such is the case, for example, with children who are too young to love, or who hate their parents for punishing them. This suggests that the beloved is the friend of the lover and the hated one is the enemy of the hater, but the implication is that some people are loved by their enemies and hated by their friends, which seems absurd. Thus, neither the lover not the beloved can always be said to be a friend to the other.
Socrates suggests that they may have been wrong in their conclusions. He turns for guidance to the poets and philosophers, who say that ‘like loves like’. Socrates argues that this aphorism must only apply to good people, since bad people are in some way unlike themselves and are just as likely to hate other bad people as anyone else. This implies that good people are friends with other good people, whereas bad people do not have any friends at all. However, Socrates remains unconvinced: like cannot be of any use to like, and if people cannot be of any use to one another, then they cannot love each other. It remains possible that they love each other because they are both good, but the good is by definition self-sufficient, and so has no desire for friendship.
What place then is there for friendship, if, when absent, good men have no need of one another (for even when alone they are sufficient for themselves), and when present have no use of one another? How can such persons ever be induced to value one another?
Socrates suspects that he may have been wrong in thinking that like loves like. He quotes Hesiod in saying that ‘the most like are most full of envy, strife, and hatred of one another, and the most unlike, of friendship’. Menexenus thinks that Hesiod is right in saying that friendship is born not in likeness but in dissimilarity, but Socrates is sceptical as the implications are not only that the enemy is the friend of the friend and the friend the friend of the enemy, but also that the just man is the friend of the unjust, the good man the friend of the bad, and so on. This, he says, is simply monstrous. Thus, neither like and like nor unlike and unlike can be friends.
If neither like and like nor unlike and unlike can be friends, then the friend of the good is neither the good nor the bad, but the neither–good–nor–bad. Since like and like cannot be friends, the neither–good–nor–bad cannot be friends with the neither–good–nor–bad, and since no one can be friends with the bad, the neither–good–nor–bad cannot be friends with the bad either. Thus, the neither–good¬–nor–bad must be friends with the good, who, Socrates says, are also possessed of beauty, that ‘soft, smooth, slippery thing’ that ‘easily slips in and permeates our souls’. While the good and beautiful cannot be friends with the good and beautiful or with the bad, there is nothing to stop them from being friends with the neither–good–nor–bad. For example, the body is neither good nor bad, but if it is corrupted by sickness, which is bad, then it becomes the friend of the physician. The fact that the body is corrupted by something bad does not make it bad, just as covering Menexenus’ auburn locks with white lead does not make them white. Socrates concludes that they have at long last discovered the nature of friendship: ‘it is the love which, by reason of the presence of evil, the neither good nor evil has of the good, either in the soul, or in the body, or anywhere.’ However, an ‘unaccountable suspicion’ comes over him, and he begins to doubt this conclusion.
If medicine, which is good, is a friend, then it is a friend for the sake of health. However, health is also good and, if good, then good for the sake of something, something which must also be good, and so on. Surely, there must some first principle of friendship or dearness for the sake of which all other things are dear. For example, if a father values his son above all things, he also values other things for the sake of his son. If, for instance, his son had drunk poisonous hemlock, and he thought that wine would save him, then he would value the wine and even the vessel that contains it. However, it is not really the wine or the vessel that he is valuing, but his son. ‘That which is only dear to us for the sake of something else is improperly said to be dear, but the truly dear is that in which all these so called dear friendships terminate.’ Socrates infers that the truly dear is the good, but points out that the good appears to be loved not for its own sake but for the sake of the bad. However, if the bad were eradicated, love and friendship would still exist, suggesting that there must be some other cause of friendship.
Socrates suggests that desire is the cause of friendship, and that he who desires, desires that of which he is in want, and hence that which is dear to him. Thus, desire, love, and friendship appear to be of the congenial, whether in soul, character, manners, or form. Socrates adds that if love is of the congenial, then the true lover must necessarily have his love returned. However, he points out that this theory falls flat if the congenial is merely the like, since the like cannot be friends with the like.
Then what is to be done? Or rather is there anything to be done? I can only, like the wisemen who argue in courts, sum up the arguments: If neither the beloved, nor the lover, nor the like, nor the unlike, nor the good, nor the congenial, nor any other of whom we spoke – for there were such a number of them that I cannot remember all – if none of these are friends, I know not what remains to be said… O Menexenus and Lysis, how ridiculous that you two boys, and I, an old boy, who would fain be one of you, should imagine ourselves to be friends – this is what the bystanders will go away and say – and as yet we have not been able to discover what is a friend!
The Lysis may seem to fail in its task of defining friendship, and on one level of course it does. There is, however, far more to the Lysis than a couple of interesting but misguided thoughts about friendship. By discussing friendship with Lysis and Menexenus as he does, Socrates is not only discussing friendship, but also demonstrating to the youths that, even though they count each other as close friends, they do not really know what friendship is, and that, whatever friendship is, it is something far deeper and far more meaningful than the puerile ‘friendship’ that they count themselves to have. In contrast to the youths, Socrates knows perfectly well what friendship is, and is only feigning ignorance so as to teach the youths: ‘…and I, an old boy, who would fain be one of you…’ More than that, by discussing friendship with Lysis and Menexenus as he does, Socrates is himself in the process of befriending them. He befriends them not with pleasant banter or gossipy chitchat, as most people befriend one another, but with the kind of philosophical conversation that is the hallmark of the deepest and most meaningful of friendships. In the course of this philosophical conversation, he tells the youths that he should ‘greatly prefer a real friend to all the gold of Darius’, thereby signifying not only that he places friendship on the same high pedestal as philosophy, to which he has devoted (and will sacrifice) his life, but also that the kind of friendship that he has in mind is so rare and uncommon that even he does not possess it. If friendship ultimately escapes definition, then this is because, like philosophy, friendship is not so much a thing-in-itself as it is a process for becoming. True friends seek together to live truer, fuller lives by relating to each other authentically and by teaching each other about the limitations of their beliefs and the defects in their character, which are a far greater source of error than mere rational confusion. For Socrates as for Plato, friendship and philosophy are aspects of one and the same impulse, one and the same love – the love that seeks to know.