An Enquiry Concerning The Principles Of Morals - App: pg. 173

The word, natural, is commonly taken in so many senses, and is of so loose a signification, that it seems vain to dispute, whether justice be natural or not. If self-love, if benevloence be natural to man; if reason and forethought be also natural; then may the same epithet be applied to justice, order, fidelity, property, society. Men's inclination, their necessities lead them to combine; their understanding and experience tell them, that this combination is impossible, where each governs himself by no rule, and pays no regard to the possessions of others: And from these passions and reflections conjoined, as soon as we observe like passions and reflections in others, the sentiment of justice, throughout all ages, has infallibly and certainly had place, to some degree or other, in every individual of the human species. In so sagacious an animal, what necessarily arises from the exertion of his intellectual facilities, may justly be esteemed natural.