I received about a week ago two sheets of your Review (The 'American Journal of Science and Arts,' March, 1860. Reprinted in 'Darwiniana,' 1876.); read them, and sent them to Hooker; they are now returned and r-read with care, and to-morrow I send them to Lyell. Your Review seems to me ADMIRABLE; by far the best which I have read. I thank you from my heart both for myself, but far more for the subject's sake. Your contrast between the views of Agassiz and such as mine is very curious and instructive. (The contrast is briefly summed up thus: "The theory of Agassiz regards the origin of species and their present general distribution over the world as equally primordial, equally supernatural; that of Darwin as equally derivative, equally natural."—'Darwiniana,' page 14.) By the way, if Agassiz writes anything on the subject, I hope you will tell me. I am charmed with your metaphor of the streamlet never running against the force of gravitation. Your distinction between an hypothesis and theory seems to me very ingenious; but I do not think it is ever followed. Every one now speaks of the undulatory THEORY of light; yet the ether is itself hypothetical, and the undulations are inferred only from explaining the phenomena of light. Even in the THEORY of gravitation is the attractive power in any way known, except by explaining the fall of the apple, and the movements of the Planets? It seems to me that an hypothesis is DEVELOPED into a theory solely by explaining an ample lot of facts. Again and again I thank you for your generous aid in discussing a view, about which you very properly hold yourself unbiassed.
My dear Gray, yours most sincerely, C. DARWIN.
P.S.—Several clergymen go far with me. Rev. L. Jenyns, a very good naturalist. Henslow will go a very little way with me, and is not shocked with me. He has just been visiting me.
[With regard to the attitude of the more liberal representatives of the Church, the following letter (already referred to) from Charles Kingsley is of interest:]
C. KINGSLEY TO CHARLES DARWIN. Eversley Rectory, Winchfield, November 18th, 1859.
Dear Sir,
I have to thank you for the unexpected honour of your book. That the Naturalist whom, of all naturalists living, I most wish to know and to learn from, should have sent a scientist like me his book, encourages me at least to observe more carefully, and perhaps more slowly.
I am so poorly (in brain), that I fear I cannot read your book just now as I ought. All I have seen of it AWES me; both with the heap of facts and the prestige of your name, and also with the clear intuition, that if you be right, I must give up much that I have believed and written.
In that I care little. Let God be true, and every man a liar! Let us know what IS, and, as old Socrates has it, epesthai to logo—follow up the villainous shifty fox of an argument, into whatsoever unexpected bogs and brakes he may lead us, if we do but run into him at last.
From two common superstitions, at least, I shall be free while judging of your books:—