_An inquiry into the cause of animal life_ 369 * * * * * AN INQUIRY INTO THE _INFLUENCE OF PHYSICAL CAUSES_ UPON THE MORAL FACULTY. DELIVERED BEFORE _THE AMERICAN PHILOSOPHICAL SOCIETY_, HELD AT PHILADELPHIA, ON THE 27TH OF FEBRUARY, 1786. * * * * * AN INQIUIRY, &c. GENTLEMEN, It was for the laudable purpose of exciting a spirit of emulation and inquiry, among the members of our body, that the founders of our society instituted an annual oration. The task of preparing, and delivering this exercise, hath devolved, once more, upon me. I have submitted to it, not because I thought myself capable of fulfilling your intentions, but because I wished, by a testimony of my obedience to your requests, to atone for my long absence from the temple of science. The subject upon which I am to have the honour of addressing you this evening is on the influence of physical causes upon the moral faculty. By the moral faculty I mean a capacity in the human mind of distinguishing and chasing good and evil, or, in other words, virtue and vice. It is a native principle, and though it be capable of improvement by experience and reflection, it is not derived from either of them. St. Paul and Cicero give us the most perfect account of it that is to be found in modern or ancient authors. "For when the Gentiles (says St. Paul), which have not the law, do by nature the things contained in the law, _these_, having not the law, are a _law_ unto themselves; which show the works of the law written in their hearts, their consciences also bearing witness, and their thoughts the mean while accusing, or else excusing another[1]." [1] Rom. i. 14, 15.