4. Moral Rules need a Proof, ergo not innate.
Another reason that makes me doubt of any innate practical principles is, that I think there cannot any one moral rule be proposed whereof A man may not justly demand A reason: which would be perfectly ridiculous and absurd if they were innate; or so much as self-evident, which every innate principle must needs be, and not need any proof to ascertain its truth, nor want any reason to gain it approbation. He would be thought void of common sense who asked on the one side, or on the other side went to give a reason why “it is impossible for the same thing to be and not to be.” It carries its own light and evidence with it, and needs no other proof: he that understands the terms assents to it for its own sake or else nothing will ever be able to prevail with him to do it. But should that most unshaken rule of morality and foundation of all social virtue, “That should do as he would be done unto,” be proposed to one who never heard of it before, but yet is of capacity to understand its meaning; might he not without any absurdity ask a reason why? And were not he that proposed it bound to make out the truth and reasonableness of it to him? Which plainly shows it not to be innate; for if it were it could neither want nor receive any proof; but must needs (at least as soon as heard and understood) be received and assented to as an unquestionable truth, which a man can by no means doubt of. So that the truth of all these moral rules plainly depends upon some other antecedent to them, and from which they must be deduced; which could not be if either they were innate or so much as self-evident.
5. Instance in keeping Compacts
That men should keep their compacts is certainly a great and undeniable rule in morality. But yet, if a Christian, who has the view of happiness and misery in another life, be asked why a man must keep his word, he will give this as a reason:—Because God, who has the power of eternal life and death, requires it of us. But if a Hobbist be asked why? he will answer:—Because the public requires it, and the Leviathan will punish you if you do not. And if one of the old philosophers had been asked, he would have answered:—Because it was dishonest, below the dignity of a man, and opposite to virtue, the highest perfection of human nature, to do otherwise.