Aristotle, Nicomachean Ethics
H. Rackham, Ed.

since those actions possess both these essentially pleasant qualities,¹ it therefore follows that the supremely happy man will require good friends, insomuch as he desires to contemplate actions that are good and that are his own, and the actions of a good man that is his friend are such. Also men think that the life of the happy man ought to be pleasant. Now a solitary man has a hard life, for it is not easy to keep up continuous activity by oneself; it is easier to do so with the aid of and in relation to other people. [6] The good man's activity therefore, which is pleasant in itself, will be more continuous if practised with friends²; and the life of the supremely happy should be continuously pleasant³ （for a good man, in virtue of his goodness, enjoys actions that conform with virtue and dislikes those that spring from wickedness, just as a skilled musician is pleased by good music and pained by bad）. [7] Moreover the society of the good may supply a sort of training in goodness, as Theognis⁴ remarks.

Again, if we examine the matter more fundamentally, it appears that a virtuous friend is essentially desirable for a virtuous man. For as has been said above, that which is essentially good is good and pleasing in itself to the virtuous man. And life is defined, in the case of animals, by the capacity for sensation; in the case of man, by the capacity for sensation and thought. But a capacity is referred to its activity, and in this its full reality consists. It appears therefore that life in the full sense is sensation or thought.But life is a thing