"By our conscience, by our reason, and by the Holy Scriptures"

This post and the previous one result from reading Our Sacred Honor: Words of Advice from the Founders in Stories, Letters, Poems, and Speeches. This quotation is from James Wilson: Pennsylvania representative to the Continental Congress, signer of the Declaration of Independence, a framer of the US Constitution, and also a Justice of the Supreme Court. Wilson in 1790:

Having thus thus stated the question—what is the efficient cause of moral obligation?—I give it this answer—the will of God. This is the supreme law. His just and full right of imposing laws, and our duty in obeying them, are the sources of our moral obligations. If am asked—why do you obey the will of God? I answer—because it is my duty to do so. If I am asked again—how do you know this to be your duty? I answer again—because I am told so by my moral sense or conscience. If I am asked a third time—how do you know that you ought to do that, of which your conscience enjoins the performance? I can only say, I feel that such is my duty. Here investigation must stop; reasoning can go no farther. The science of morals, as well as other sciences, is founded on truths, that cannot be discovered or proved by reasoning. Reason is confined to the investigation of unknown truths by the means of such as are known. We cannot, therefore, begin to reason, till we are furnished, otherwise than by reason, with some truths, on which we can found our arguments. Even in mathematics, we must be provided with axioms perceived intuitively to be true, before our demonstrations can commence. Morality, like mathematics, has its intuitive truths, without which we cannot make a single step in our reasonings upon the subject. Such an intuitive truth is that, with which we just now closed our investigation. If a person was not possessed of the feeling before mentioned; it would not be in the power of arguments, to give him any conception of the distinction between right and wrong. These terms would be to him equally unintelligible, as the term color to one who was born and has continued blind. But that there is, in human nature, such a moral principle, has been felt and acknowledged in all ages and nations.

Now that we have stated and answered the first question; let us proceed to the consideration of the second—how shall we, in particular instances, learn the dictates of our duty, and make, with accuracy, the proper distinction between right and wrong; in other words, how shall we, in particular cases, discover the will of God? We discover it by our conscience, by our reason, and by the Holy Scriptures. The law of nature and the law of revelation are both divine; they flow, though in different channels, from the same adorable source. It is, indeed, preposterous to separate them from each other. The object of both is—to discover the will of God—and both are necessary for the accomplishment of that end.

James Wilson, The Laws of Nature, 1790