The copy of your Second thoughts on Instinctive impulses with the letter accompanying it, was recieved 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 shews 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 it’s observance in practice. of all the theories on this question, the most whimsical seems to have been that of Woollaston, 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 it’s foundation, it is as if a tree, taken up by the roots, had it’s stem reversed in the air, and one of it’s 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 defections1 from the Platonic Christianity of the priests is to Deism, in Catholic countries they are to Atheism. Diderot, Dalembert, 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.

The το καλον of others is founded in a different faculty, that of taste, which is not even a branch of morality. we have indeed an innate sense of what we call beautiful: but that is exercised chiefly on subjects addressed to the fancy, whether thro’ the eye, in visible forms, as landscape, animal figure, dress, drapery, architecture, the composition of colours Etc. or to the imagination directly, as imagery, style, or measure in prose or poetry, or whatever else constitutes the domain of criticism or taste, a faculty entirely distinct from the moral one. Self-interest, or rather Self love, or Egoism, has been more plausibly substituted as the basis of morality. but I consider our relations with others as constituting the boundaries of morality. with ourselves we stand on the ground of identity, not of relation; which last, requiring two subjects, excludes self-love confined to a single one. to ourselves, in strict language, we can owe no duties, obligation requiring also two parties. self-love therefore is no part of morality. indeed it is exactly it’s counterpart. it is the sole antagonist of virtue, leading us constantly by our propensities to self-gratification in violation of our moral duties to others. accordingly it is against this enemy that are erected the batteries of moralists and religionists, as the only obstacle to the practice of morality. take from man his selfish propensities, and he can have nothing to seduce him from the practice of virtue. or subdue those propensities by education, instruction, or restraint, and virtue remains without a competitor. Egoism, in a broader sense, has been thus presented as the source of moral action. it has been said that we feed the hungry, clothe the naked, bind up the wounds of the man beaten by thieves, pour oil and wine into them, set him on our own beast, and bring him to the inn, because we recieve ourselves pleasure from these acts. so Helvetius, one of the best men on earth, and the most ingenious advocate of this principle, after defining ‘interest’ to mean, not merely that which is pecuniary, but whatever may procure us pleasure or withdraw us from pain, [de l’Esprit. 2. 1.] says [ib. 2. 2.] ‘the humane man is he to whom the sight of misfortune is insupportable and who, to rescue himself from this spectacle, is forced to succour the unfortunate object.’ this indeed is true. but it is one step short of the ultimate question. these good acts give us pleasure: but2 how happens it that they give us pleasure? because nature hath implanted in our breasts a love of others, a sense of duty to them, a moral instinct in short, which prompts us irresistibly to feel and to succour their distresses; and protests against the language of Helvetius [ib. 2. 5.] ‘what other motive than self interest could determine a man to generous actions? it is as impossible for him to love what is good for the sake of good, as to love evil for the sake of evil.’ the creator would indeed have been a bungling artist,3 had he intended man for a social animal, without planting in him social dispositions. it is true they are not planted in every man; because there is no rule without exceptions: but it is false reasoning which converts exceptions into the general rule. some men are born without the organs of sight, or of hearing, or without hands. yet it would be wrong to say that man is born without these faculties: and sight, hearing and hands may with truth enter into the general definition of Man. the want or imperfection4 of the moral sense in some men, like the want or imperfection of the senses of sight and hearing in others, is no proof that it is a general characteristic of the species. when it is wanting we endeavor to supply the defect by education, by appeals to reason and calculation, by presenting to the being so unhappily conformed other motives to do good, and to eschew evil; such as the love, or the hatred or rejection of those among whom he lives and whose society is necessary to his happiness, and even existence; demonstrations by sound calculation that honesty promotes interest in the long run; the rewards & penalties established by the laws; and ultimately the prospects of a future state of retribution for the evil as well as the good done while here. these are the correctives which are supplied by education, and which exercise the functions of the moralist, the preacher & legislator: and they lead into a course of correct action all those whose depravity is not too5 profound to be eradicated. some have argued against the existence of a moral sense, by saying that if nature had given us such a sense, impelling us to virtuous actions, and warning us against those which are vicious, then nature must also have designated, by some particular ear-marks, the two sets of actions which are, in themselves, the one virtuous, and the other vicious: whereas we find in fact, that the same actions are deemed virtuous in one country, and vicious in another. the answer is that nature has constituted utility to man the standard & test of virtue. men living in different countries, under different circumstances, different habits, and regimens, may have different utilities. the same act therefore may be useful, and consequently virtuous, in one country, which is injurious and vicious in another differently circumstanced. I sincerely then believe with you in the general existence of a moral instinct. I think it the brightest gem with which the human character is studded; and the want of it as more degrading than the most hideous of the bodily deformities. I am happy in reviewing the roll of associates in this principle which you present in your 2d letter, some of which I had not before met with. to these might be added Ld Kaims, one of the ablest of our advocates, who goes so far as to say, in his Principles of Natural religion, that a man owes no duty to which he is not urged by some impulsive feeling. this is correct if referred to the standard of general feeling in the given case, and not to the feeling of a single individual. perhaps I may misquote him, it being fifty years since I read his book.

The leisure and solitude of my situation here has led me to the indiscretion of taxing you with a long letter on a subject whereon nothing new can be offered you. I will indulge myself no further than to repeat the assurances of my continued esteem & respect.

Th: Jefferson