I have to thank you, dear Sir, for the copy I have recieved of your system of universal science, for which I presume I am indebted to yourself. it will be a monument of the learning of the author and of the analysing powers of his mind. whether it may be adopted in general use is yet to be seen. these analytical views indeed must always be ramified according to their object. yours is on the great scale of a Methodical Encyclopedia of all human sciences, taking, for the basis of their distribution, Matter, Mind, and the union of both. Ld Bacon founded his 1st great division on the faculties of the mind which have cognisance of these sciences. it does not seem to have been observed by any one that the origination of this division was not with him. it had been proposed by Charron, more than 20. years before in his book de la Sagesse. B. 1. c. 14. and an imperfect ascription of the sciences to these respective faculties was there attempted. this excellent moral work was published in 1600. Ld Bacon is said not to have entered on his great works until his retirement from public office in 1621.   Where sciences are to be arranged in accomodation to the schools of an University, they will be grouped to coincide with the kindred qualifications of Professors in ordinary. for a library again, which was my object, their divisions and subdivisions will be made such as to throw convenient masses of books under each separate head. thus in the library of a Physician the books of that science, of which he has many, will be subdivided under many heads; and those of Law, of which he has few, will be placed under a single one. The Lawyer again will distribute his law-books under many subdivisions, his Medical under a single one. Your idea of making the subject matter of the sciences the basis of their distribution is certainly, more reasonable than that of the faculties to which they are addressed. The materialists will perhaps criticise a basis, one half of which they will say is a non-existence; adhering to the axioms of Aristotle ‘nihil est in intellectu quod prius non fuerit in sensu’ and affirming that we can have no evidence of any existence which impresses no sense. of this opinion were most of the antient philosophers, and several of the early and orthodox Fathers of the Christian church indeed Jesus himself, the founder of our religion, was unquestionably a materialist as to man. in all his doctrines of the resurrection he teaches expressly that the body is to rise in substance. in the Apostles’ creed we all declare that we believe in the ‘resurrection of the body’. Jesus says that ‘God is a Spirit’ [πνευμα] without defining it. Tertullian supplies the definition, ‘quis negabit Deum esse corpus, etsi Deus Spiritus? spiritus etiam corporis suí generis in suâ effigie.’ and Origin ‘ασωματον accipi, docet, pro eo quod non est simile huic nostro crastiori et visibli corpori, sed quod est natuaraliter subtile, et velut aura tenue.’ the modern philosophers mostly consider thought as a function of our material organisation; and Locke particularly among them charges with blasphemy those who deny that Omnipotence could give the faculty of thinking to certain combinations of matter.

Were I to recompose my tabular view of the sciences, I should certainly transpose a particular branch. The Naturalists, you know, distribute the history of Nature into 3. kingdoms or departments, Zoology, botany, mineralogy. Ideology or Mind however occupies so much space in the field of science, that we might perhaps erect it into a 4th kingdom or department. but, in as much as it makes a part of the animal construction only, it would be more proper to subdivide zoology into physical and moral. the latter including ideology. ethics, and mental science generally, in my catalogue, considering Ethics, as well as Religion, as supplements to law, in the government of man, I had placed them in that sequence. but certainly the faculty of thought belongs to animal history, is an important portion of it, and should there find it’s place.   But these are speculations in which I do not now permit myself to labour. my mind unwillingly engages in severe investigations. it’s energies indeed are no longer equal to them. being to thank you for your book, it’s subject has run away with me into a labyrinth of ideas no longer familiar, and writing also has become a slow and irksome operation with me. I have been obliged to avail myself of the pen of a grand-daughter for this communication. I will here therefore close my task of thinking, hers of writing, and yours of reading, with assurance of my constant and high respect and esteem.

Th: Jefferson