I do not believe you have read much of Priestley's "corruptions of Christianity," his history of early opinions of Jesus Christ, his predestination, his no-soul system, or his controversy with Horsley.
I have been a diligent student for many years in books whose titles you have never seen. In Priestley's and Linsay's writings; in Farmer, in Cappe, in Tucker's or Edwards searches; Light of Nature pursued; in Edwards and Hopkins, and lately in Ezra Styles Ely; his reverend and learned panegyrists, and his elegant and spirited opponents. I am not wholly uninformed of the controversies in Germany, and the learned researches of universities and professors, in which the sanctity of the Bible and the inspiration of its authors are taken for granted, or waived, or admitted, or not denied. I have also read Condorcet's Progress of the Human Mind.
Now, what is all this to you? No more, than if I should tell you that I read Dr. Clark, and Dr. Waterland, and Emlyn, and Leland's view or review of the Deistical writers more than fifty years ago; which is a literal truth. I blame you not for reading Euclid and Newton, Thucydides and Theocrites; for I believe you will find as much entertainment and instruction in them, as I have found in my theological and ecclesiastical instructors; or even as I have found in a profound investigation of the life, writings, and doctrines of Erastus, whose disciples were Milton, Harrington, Selden, St. John, the Chief Justice, father of Bolingbroke, and others, the choicest spirits of their age; or in Le Harpe's history of the philosophy of the eighteenth century, or in Vander Kemp's vast map of the causes of the revolutionary spirit in the same and preceding centuries. These things are to me, at present, the marbles and nine-pins of old age; I will not say the beads and prayer-books.
I agree with you, as far as you go, most cordially, and I think solidly. How much farther I go, how much more I believe than you, I may explain in a future letter. Thus much I will say at present, I have found so many difficulties, that I am not astonished at your stopping where you are; and so far from sentencing you to perdition, I hope soon to meet you in another country.