My dear Wallace, (In the note referred to, dated January 27, Mr. Wallace wrote:--"Many thanks for your first volume which I have just finished reading through with the greatest pleasure and interest; and I have also to thank you for the great tenderness with which you have treated me and my heresies."The heresy is the limitation of natural selection as applied to man. My father wrote ('Descent of Man,' i. page 137):--"I cannot therefore understand how it is that Mr. Wallace maintains that 'natural selection could only have endowed the savage with a brain a little superior to that of an ape.'" In the above quoted letter Mr. Wallace wrote:--"Your chapters on 'Man' are of intense interest, but as touching my special heresy not as yet altogether convincing, though of course I fully agree with every word and every argument which goes to prove the evolution or development of man out of a lower form.")Your note has given me very great pleasure, chiefly because I was so anxious not to treat you with the least disrespect, and it is so difficult to speak fairly when differing from any one. If I had offended you, it would have grieved me more than you will readily believe. Secondly, I am greatly pleased to hear that Volume I. interests you; I have got so sick of the whole subject that I felt in utter doubt about the value of any part.
I intended, when speaking of females not having been specially modified for protection, to include the prevention of characters acquired by the male being transmitted to the female; but I now see it would have been better to have said "specially acted on," or some such term. Possibly my intention may be clearer in Volume II. Let me say that my conclusions are chiefly founded on the consideration of all animals taken in a body, bearing in mind how common the rules of sexual differences appear to be in all classes. The first copy of the chapter on Lepidoptera agreed pretty closely with you. I then worked on, came back to Lepidoptera, and thought myself compelled to alter it--finished Sexual Selection and for the last time went over Lepidoptera, and again I felt forced to alter it. I hope to God there will be nothing disagreeable to you in Volume II., and that Ihave spoken fairly of your views; I am fearful on this head, because I have just read (but not with sufficient care) Mivart's book ('The Genesis of Species,' by St. G. Mivart, 1871.), and I feel ABSOLUTELY CERTAIN that he meant to be fair (but he was stimulated by theological fervour); yet I do not think he has been quite fair...The part which, I think, will have most influence is where he gives the whole series of cases like that of the whalebone, in which we cannot explain the gradational steps; but such cases have no weight on my mind--if a few fish were extinct, who on earth would have ventured even to conjecture that lungs had originated in a swim-bladder? In such a case as the Thylacine, I think he was bound to say that the resemblance of the jaw to that of the dog is superficial; the number and correspondence and development of teeth being widely different. Ithink again when speaking of the necessity of altering a number of characters together, he ought to have thought of man having power by selection to modify simultaneously or almost simultaneously many points, as in ****** a greyhound or racehorse--as enlarged upon in my 'Domestic Animals.' Mivart is savage or contemptuous about my "moral sense," and so probably will you be. I am extremely pleased that he agrees with my position, AS FAR AS ANIMAL NATURE IS CONCERNED, of man in the series; or if anything, thinks I have erred in ****** him too distinct.
Forgive me for scribbling at such length. You have put me quite in good spirits; I did so dread having been unintentionally unfair towards your views. I hope earnestly the second volume will escape as well. I care now very little what others say. As for our not quite agreeing, really in such complex subjects, it is almost impossible for two men who arrive independently at their conclusions to agree fully, it would be unnatural for them to do so.
Yours ever, very sincerely, CH. DARWIN.
[Professor Haeckel seems to have been one of the first to write to my father about the 'Descent of Man.' I quote from his reply:--"I must send you a few words to thank you for your interesting, and I may truly say, charming letter. I am delighted that you approve of my book, as far as you have read it. I felt very great difficulty and doubt how often I ought to allude to what you have published; strictly speaking every idea, although occurring independently to me, if published by you previously ought to have appeared as if taken from your works, but this would have made my book very dull reading; and I hoped that a full acknowledgment at the beginning would suffice. (In the introduction to the 'Descent of Man' the author wrote:--"This last naturalist [Haeckel]...has recently...published his 'Naturliche Schopfungs-geschichte,' in which he fully discusses the genealogy of man.
If this work had appeared before my essay had been written, I should probably never have completed it. Almost all the conclusions at which Ihave arrived, I find confirmed by this naturalist, whose knowledge on many points is much fuller than mine.") I cannot tell you how glad I am to find that I have expressed my high admiration of your labours with sufficient clearness; I am sure that I have not expressed it too strongly."]
CHARLES DARWIN TO A.R. WALLACE.
Down, March 16, 1871.
My dear Wallace, I have just read your grand review. ("Academy", March 15, 1871.) It is in every way as kindly expressed towards myself as it is excellent in matter.