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.
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:--
1. I have long since, from watching the crossing of domesticated animals and plants, learnt to disbelieve the dogma of the permanence of species.
2. I have gradually learnt to see that it is just as noble a conception of Deity, to believe that he created primal forms capable of self development into all forms needful pro tempore and pro loco, as to believe that He required a fresh act of intervention to supply the lacunas which He Himself had made. I question whether the former be not the loftier thought.
Be it as it may, I shall prize your book, both for itself, and as a proof that you are aware of the existence of such a person as
Your faithful servant, C. KINGSLEY.
[My father's old friend, the Rev. J. Brodie Innes, of Milton Brodie, who was for many years Vicar of Down, writes in the same spirit:
"We never attacked each other. Before I knew Mr. Darwin I had adopted, and publicly expressed, the principle that the study of natural history, geology, and science in general, should be pursued without reference to the Bible. That the Book of Nature and Scripture came from the same Divine source, ran in parallel lines, and when properly understood would never cross...
"His views on this subject were very much to the same effect from his side. Of course any conversations we may have had on purely religious subjects are as sacredly private now as in his life; but the quaint conclusion of one may be given. We had been speaking of the apparent contradiction of some supposed discoveries with the Book of Genesis; he said, 'you are (it would have been more correct to say you ought to be) a theologian, I am a naturalist, the lines are separate. I endeavour to discover facts without considering what is said in the Book of Genesis. I do not attack Moses, and I think Moses can take care of himself.' To the same effect he wrote more recently, 'I cannot remember that I ever published a word directly against religion or the clergy; but if you were to read a little pamphlet which I received a couple of days ago by a clergyman, you would laugh, and admit that I had some excuse for bitterness.