When we take a view of the universe, in its parts, general or particular, it is impossible for the human mind not to perceive and feel a conviction of design, consummate skill, and indefinite power in every atom of its composition. So irresistible are these evidences of an intelligent and powerful Agent, that of the infinite numbers of men who have existed through all time, they have believed, in the proportion of a million at least to a unit, in the hypothesis of an eternal pre-existence of a Creator, rather than in that of a self existing universe.[566]
From this passage, it would seem that Jefferson founded his belief in the existence of God on the two well-known arguments: the order of the Universe and the general consensus of opinion. If it were so, he would follow close on the steps of the English deists of the school of Pope. But religion to him was something more than the mere "acknowledgement" and "adoration of the benevolent Governor of the world";
It is more than an inner conviction of the existence of the Creator; true religion is morality. If by religion we are to understand sectarian dogmas, in which no two of them agree, then your exclamation on that hypothesis is just, "that this would be the best possible of all possible worlds, if there were no religion in it." But if the moral precepts, innate in man, and made a part of his physical constitution, as necessary for a social being, if the sublime doctrines of philanthropism and deism taught us by Jesus of Nazareth, in which we all agree, constitute true religion, then, without it, this would be, as you again say, "something not fit to be named even, indeed, a hell."[567]
On this point as on so many others Jefferson is distinctly an eighteenth-century man. One of the pet schemes of the philosophers was to prove that there is no necessary connection between religion and morality. It was an essential article of the philosophical creed from Pierre Bayle to Jefferson, and long before them, Montaigne had filled his "Essays" with countless anecdotes and examples tending to prove this point. But Jefferson went one step farther than most of the French philosophers, with the exception of Rousseau. Morality is not founded on a religious basis; religion is morality. This being accepted, it remains to determine the foundation of morality. In a letter written to Thomas Law during the summer of 1814, Jefferson examined the different solutions proposed by theologians and philosophers and clearly indicated his preference.
"It was vain to say that it was truth; for truth is elusive, unattainable, and there is no certain criticism of it." It is not either the "love of God", for an atheist may have morality, and "Diderot, d'Holbach, Condorcet, are known to have been the most virtuous of men." It is not either the to kalon, for many men are deprived of any æsthetic sense. Self-interest is more satisfactory, but even the demonstration given by Helvétius is not perfectly convincing. All these explanations are one step short of the ultimate question.
The truth of the matter is, that Nature has 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 succour their distresses. It is true that these social dispositions are not implanted 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. When the moral sense 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. But nature has constituted utility to man the social test of virtue. The same act may be useful and consequently virtuous in a 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 is the brightest gem with which the human character is studded, and the want of it is more degrading than the most hideous of the bodily deformities.[568]
The test of morality then becomes, not self-interest, as Helvétius had maintained (and Jefferson reproved Destutt de Tracy for having accepted this theory), but general interest and social utility. This is almost the criterium of Kant and one would be tempted to press this parallelism, if there was any reason to believe that the Philosopher of Monticello had ever heard the name of the author of "Practical Reason." On this point, as on so many others, Jefferson differs radically from Rousseau, who admitted also a benevolent governor of the world and the existence of a moral instinct, but who would have strenuously denied that this moral instinct was nothing but the social instinct. Jefferson, on the contrary, is led to recognize the existence of morality, chiefly because, man being a social being, society cannot be organized and subsist if it is not composed of moral beings.
Reading, reflection and time have convinced me that the interests of society require the observation of those moral precepts in which all religions agree, (for all forbid us to murder, steal, plunder or bear false witness,) and that we should not intermeddle with the particular dogmas in which all religions differ, and which are totally unconnected with morality. In all of them we see good men, and as many in one as another. The varieties of structures of action of the human mind as in those in the body, are the work of our Creator, against which it cannot be a religious duty to erect the standard of uniformity. The practice of morality being necessary for the well-being of society, he has taken care to impress its precepts so indelibly on our hearts that they shall not be effaced by the subtleties of our brain.[569]
This was stated more humorously by John Adams after they had treated the subject exhaustively in a series of letters: "Vain man, mind your own business. Do no wrong—; do all the good you can. Eat your canvasback ducks, drink your Burgundy. Sleep your siesta when necessary, and TRUST IN GOD."[570]