Aristotle, Nicomachean Ethics
H. Rackham, Ed.

For we admit that one should love one's best friend most; but the best friend is he that, when he wishes a person's good, wishes it for that person's own sake, even though nobody will ever know of it. Now this condition is most fully realized in a man's regard for himself, as indeed are all the other attributes that make up the definition of a friend; for it has been said already¹ that all the feelings that constitute friendship for others are an extension of regard for self. Moreover, all the proverbs agree with this; for example, ‘Friends have one soul between them,’² ‘Friends' goods are common property,’ ‘Amity is equality,’ ‘The knee is nearer than the shin.’³ All of these sayings will apply most fully to oneself; for a man is his own best friend. Therefore he ought to love himself most.

So it is naturally debated which of these two views we ought to adopt, since each of them has some plausibility. [3]

Now where there is a conflict of opinion the proper course is doubtless to get the two views clearly distinguished, and to define how far and in what way each of them is true. So probably the matter may become clear if we ascertain what meaning each side attaches to the term ‘self-love.’ [4]

Those then who make it a term of reproach call men lovers of self when they assign to themselves the larger share of money, honors, or bodily pleasures; since these are the things which most men desire and set their hearts on as being the greatest goods, and which accordingly they compete with each other to obtain. Now those who take more than their share of these things are men who indulge their appetites, and generally their passions and the irrational part of their souls. But most men are of this kind. Accordingly the use of the term ‘lover of self’ as a reproach has arisen from the fact that self-love of the ordinary kind is bad. Hence self-love is rightly censured in those who are lovers of self in this sense. [5] And that it is those who take too large a share of things of this sort whom most people usually mean when they speak of lovers of self, is clear enough. For if a man were always bent on outdoing everybody else in acting justly or temperately or in displaying any other of the virtues, and in general were always trying to secure for himself moral nobility, no one will charge him with love of self nor find any fault with him. [6] Yet as a matter of fact such a man might be held to be a lover of self in an exceptional degree. At all events he takes for himself the things that are noblest and most truly good. Also it is the most dominant part of himself that he indulges and obeys in everything. But （a） as in the state it is the sovereign that is held in the fullest sense to be the state, and in any other composite whole it is the dominant part that is deemed especially to be that whole, so it is with man. He therefore who loves and indulges the dominant part of himself is a lover of self in the fullest degree. Again （b） , the terms ‘self-restrained’ and ‘unrestrained’ denote being restrained or not by one's intellect, and thus imply that the intellect is the man himself.