Man, no doubt, owes many other moral duties to his fellow men; such as to feed the hungry, clothe the naked, shelter the homeless, care for the sick, protect the defenseless, assist the weak, and enlighten the ignorant. But these are simply moral duties, of which each man must be his own judge, in each particular case, as to whether, and how, and how far, he can, or will perform them.

Natural Law (ed. 1882)