Montezillo May 12th. 1820
I have received with great pleasure your favour of March 14th. Mr Ticknor informes me that Dugald Stuart was not reduced to a state of Idiocy as I had been informed—but that he was in bad Health—and by the advice of his friends and Physicians to remove to Devenshire in England in hopes by the change of air tranquil repose and retirement from the irritation of society he might recover his health—But he said there was something mysterious in the business and the gentlemen in Scotland did not love to converse upon the subject, but chose to wave as well as they could, questions concerning it—That he had not been in London superintending any work.
This account leaves ample scope for all our conjectures, but in all events it is very melancholy that so profound a genius should be obliged to retire before he had exhausted all his speculations for the Illumination of his Species; for, indeed, all his writings are melancholy; they are humiliating; for they show us our ignorance, and the utmost limits to which the human understanding may hope to go in this Inferior World. They ought, however, to be consolatory, because they furnish us with abundance of your pillows of Ignorance—an expression that I very much admire—on which to repose our puzzeld heads—
The question between spirit and matter appears to me nugatory because we have neither evidence nor idea of either—all that we certainly know is that some substance exists, which must be the cause of all the qualitys, and Attributes which we perceive Extension, Solidity, Perception, memory, and Reason, for all these are Attributes, or adjectives, and not Essences or substantives
Sixty years ago, at College, I read Berkley—and from that time to this I have been fully persuaded that we know nothing of Essences—That some Essence does exist, which causes our minds with all their ideas—And this visible World with all its wonders—I am certain that this cause is wise Benevolent and powerful, beyond all conception I cannot doubt—but what it is, I cannot conjecture—
Suppose we dwell a little on this matter—The Infinite devisibility of it had long ago been demonstrated by Mathematicians—When the Marquis De L’Hospital arose and demonstrated that there were quantities and not infinitely little—but others infinitely less than those infinitely littles—and he might have gone on for what I know to all Eternity demonstrating that there are quantities infinitely less than those last infinitely littles—and the Phenomena of nature seems to coincide with De L’Hospitals demonstrations.—For example Astronomers inform us that the Star draconis is distant from the Earth 38,000,000,000,000, miles. The Light that proceed’s from that Star therefore, must fill a Sphere of 78,000,000,000,000, miles in diameter—and every part of that sphere equal to the size of the pupil of the human Eye—light is Matter and every ray—every pencil of that light is made up of particles very little indeed—if not infinitely little—or infinitely less than infinitely little—If this Matter is not fine enough—and subtle enough to perceive to feel and to think—it is too subtle for any human intellect or imagination to conceive—for I defy any human mind to form any idea of any-thing so small—however after all Matter is but Matter—if it is infinitely less—than infinitely little—it is incapable of memory; Judgement, or feeling, or pleasure or pain as far as I can conceive—yet for any-thing I know it may be as capable of Sensation and reflection as Spirit—for I confess I know not how Spirit can think feel or act any more than Matter—In truth I cannot conceive how either can move or think—so that I must repose upon your pillow of ignorance which I find very soft and consoleing—for it absolves my conscience from all culpability in this respect—But I insist upon it that the Saint has as good a right to groan at the Philosopher for asserting that there is nothing but matter in the Universe—As the Philosopher has to laugh at the Saint for saying that there are both Matter and Spirit—Or as the Infidel has to despise Berckley for saying that we cannot prove that there is any-thing in the Universe but Spirit and Idea—for this indeed is all he asserted for he never denied the Existence of Matter—After all I agree that both the groan and the Smile is impertinent—for neither knows what he says—or what he affirms—and I will say of both as Turgot says of Berkley in his Article of Existence in the Encyclopedia—it is easier to despise than to answer them—
Cabanis’s Ignition can destroy nothing in the Magnet—But motion magnetism Electricity Galvanism, Attraction, Repulsion, are nothing but motion—and have no more relation to Analogy or resemblance, to memory, Perception, Conception or Volition, than black has to white, or falshood to truth—or right to wrong—When two Billiard Balls meet and repell each-other we know nothing of the cause—Contact or repulsion than we do of Spirit We see nothing but motion in the Case—and what motion is—we know not—
Oh delightful Ignorance—when I arrive at a certainty that I am Ignorant and that I always must be ignorant while I live I am happy for I know I can no longer be responsible—
We shall meet here after and laugh at our present botherations—
So believes your old Friend—
DLC: Papers of Thomas Jefferson.