Philo: On the Unchangableness of God

IV. (16) But some persons, through their selflove, have incurred not only defeat but even death also. At all events Onan, "knowing that the seed should not be his,"8 did not desist from injuring the rational principle, which is the best thing in kind of all existing things, until he himself met with utter destruction. And this, too, very properly and deservedly; (17) for if some men do all things for the sake of themselves alone, not with a view to the honour of their parents, or the proper regulation of their children, or the salvation of their country, or the guardianship of the laws, or the preservation of good morals, or with a view to the due performance of any public or private duty, or of a proper celebration of sacred rites, or the pious worship due to the gods, they will be deservedly miserable.

(18) For the sake of one of the objects which I have mentioned, it is glorious even to quit life itself. But these men say that, unless they are likely to gain some pleasure by the pursuit of them, they would disregard the whole lot of themù glorious objects as they are. Therefore, the incorruptible God banishes the wicked exposition of unnatural opinion, which is named Onan. (19) And altogether these persons are to be detested who beget children for themselves, that is to say, who, pursuing their own private advantage alone, disregard all other objects, as if they had been born for themselves alone, and not for ten thousand other persons also, for their fathers, and their mothers, and their wives, and their children, and their country, and for all mankind.

And if we must go further and add any thing to this enumeration, we may say for heaven, and earth, and the whole universe, and for the sciences, and for the virtues, and for the Father and Ruler of all; to every one of which a man ought to pay what is due to the best of his power, not looking upon all the world as an addition to himself, but on himself as an addition to the rest of the world.