I must add more particular thanks for the kind expressions of your letter towards myself. These testimonies of approbation from my fellow-citizens, offered too when the lapse of time may have cooled and matured their opinions, are an ample reward for such services as I have been able to render them, and are peculiarly gratifying in a state of retirement and reflection. I pray you to accept the assurance of my respect.
DEAR SIR,--The copy of your Second Thoughts on Instinctive Impulses, with the letter accompanying it, was received just as I was setting out on a journey to this place, two or three days' distant from Monticello. I brought it with me and read it with great satisfaction, and with the more as it contained exactly my own creed on the foundation of morality in man. It is really curious that on a question so fundamental, such a variety of opinions should have prevailed among men, and those, too, of the most exemplary virtue and first order of understanding. It shows how necessary was the care of the Creator in making the moral principle so much a part of our constitution as that no errors of reasoning or of speculation might lead us astray from its observance in practice. Of all the theories on this question, the most whimsical seems to have been that of Wollaston, who considers _truth_ as the foundation of morality. The thief who steals your guinea does wrong only inasmuch as he acts a lie in using your guinea as if it were his own. Truth is certainly a branch of morality, and a very important one to society. But presented as its foundation, it is as if a tree taken up by the roots, had its stem reversed in the air, and one of its branches planted in the ground. Some have made the _love of God_ the foundation of morality. This, too, is but a branch of our moral duties, which are generally divided into duties to God and duties to man. If we did a good act merely from the love of God and a belief that it is pleasing to Him, whence arises the morality of the Atheist? It is idle to say, as some do, that no such being exists. We have the same evidence of the fact as of most of those we act on, to-wit: their own affirmations, and their reasonings in support of them. I have observed, indeed, generally, that while in protestant countries the defections from the Platonic Christianity of the priests is to Deism, in catholic countries they are to Atheism. Diderot, D'Alembert, D'Holbach, Condorcet, are known to have been among the most virtuous of men. Their virtue, then, must have had some other foundation than the love of God.