Friendship

Philia (φιλία) is friendship, affection, the love between friends — from philos, 'dear' or 'loving', the same root that opens the word philosophy itself. Broader and calmer than the passion of erōs, it covers the bonds of comrades, kin, and fellow citizens, and the goodwill that holds a community together.

Plato and Aristotle

Plato's Lysis probes, and leaves unresolved, the question of what makes us friends — like drawn to like, or opposite to opposite, or each to the good. Aristotle gives friendship its fullest treatment, devoting two whole books of the Nicomachean Ethics to it. He distinguishes friendships of utility and of pleasure from the rare and lasting friendship of virtue, in which each loves the other for the other's own sake; such a friend, he says, is 'another self', and no one would choose to live without friends though he had all other goods.

Cosmic love

The word reached even into cosmology. The philosopher Empedocles made Philotēs — Love, or philia — one of the two great forces of the universe, the power that draws the elements together into one, forever at war with Strife, which drives them apart. Friendship, in this vision, is nothing less than the principle of unity in things.