between any and every one who undertakes to perform some task, and his employer in the widest sense of the word. Hence every duty involves a right; since no one undertakes an obligation without a motive, which means, in this case, without seeing some advantage for himself. There is only one obligation that I know of which is not subject to an agreement, but arises directly and solely through an act; this is because one of the persons with whom it has to do was not in existence when it was contracted.

I refer to the duty of parents towards their children. Whoever brings a child into the world, has incumbent on him the duty of supporting his offspring, until the latter is able to maintain himself; and should this time never come, owing to incapacity from blindness, deformity, cretinism, and the like, neither does the duty