manner there is a faculty which reflects upon and perceives the fact that we are working, so that we can perceive that we perceive and intellectually know that we intellectually know: but to perceive that we perceive or that we intellectually know is to perceive that we exist, since existence was defined to be perceiving or intellectually knowing. Now to perceive that one lives is a thing pleasant in itself, life being a thing naturally good, and the perceiving of the presence in ourselves of things naturally good being pleasant.
Therefore the fact of living is choice-worthy, and to the good specially so since existence is good and pleasant to them: for they receive pleasure from the internal consciousness of that which in itself is good.
But the good man is to his friend as to himself, friend being but a name for a second Self; therefore as his own existence is choice-worthy to each so too, or similarly at least, is his friend’s existence. But the ground of one’s own existence being choice-worthy is the perceiving of one’s self being good, any such perception being in itself pleasant. Therefore one ought to be thoroughly conscious of one’s friend’s existence, which will result from living with him, that is sharing in his words and thoughts: for this is the meaning of the term as applied to the human species, not mere feeding together as in the case of brutes.