Universal Friendship
Friendship of all things towards all was most clearly unfolded by Pythagoras. Indeed, the friendship of Gods towards men he explained through piety and scientific cultivation; but that of teachings towards each other, and generally of the soul to the body, of the rational towards the irrational part he unfolded, through philosophy and its teaching. That of men towards each other, and of citizens, he justified through proper legislation; that of strangers, through the common possession of a body; that between man and wife, children, brothers or kindred, through the unperverted ties of nature. In short, he taught the friendship of all for all; and still further, of certain animals, through justice, and common physical experiences. But the pacification and conciliation of the body, which is mortal by itself, and of its latent immortal powers, he enforced through health, and temperate diet suitable thereto, in imitation of the ever-healthy condition of the mundane elements.
From, Iamblichus: The Life of Pythagoras. Ch. 33. Translated by Kenneth S. Guthrie.