“Moral instinct I call that natural bent or inclination which prompts us to approve of certain things as good and commendable, and to condemn others as bad and blameable, independent of reflexion. Or if any one has a mind to distinguish this instinct by the name of moral sense, as Mr. Hutchinson has done, I shall then say, that it is a faculty of the mind, which instantly discerns, in certain cases, moral good and evil, by a kind of sensation and taste, independent of reason and reflexion.
Examples.II. Thus at the sight of a man in misery or pain, we feel immediately a sense of compassion, which prompts us to relieve him. The first emotion that strikes us, after receiving a benefit, is to acknowledge the favour, and to thank our benefactor. The first disposition of one man towards another, abstracting from any particular reason he may have of hatred or fear, is a sense of benevolence, as towards his fellow-creature, with whom he finds himself connected by a conformity of nature and wants. We likewise observe, that without any great thought or reasoning, a child, or untutored peasant, is sensible that ingratitude is a vice, and exclaims against perfidy, as a black and unjust action, which highly shocks him, and is absolutely repugnant to his nature. On the contrary, to keep one’s word, to be grateful for a benefit, to pay every body their due, to honour our parents, to comfort those who are in distress or misery, are all so many actions which we cannot but approve and esteem as just, good, honest, beneficent, and useful to mankind. Hence the mind is pleased to see or hear such acts of equity, sincerity, humanity, and beneficence; the heart is touched and moved; and reading them in history we are seized with admiration, and extol the happiness of the age, nation, or family, distinguished by such noble examples. As for criminal instances, we cannot see or hear them mentioned, without contempt or indignation.”
This is what separates man from the mere beasts. Man knows what is good and what is not-good when he sees it. “Natural law” is rooted in man’s nature, not the Bible, nor in arbitrary positive law.