I have been a most ungrateful and ungracious man not to have written to you an immense time ago to thank you heartily for the "Nation", and for all your most kind aid in regard to the American edition [of 'Animals and Plants']. But I have been of late overwhelmed with letters, which I was forced to answer, and so put off writing to you. This morning I received the American edition (which looks capital), with your nice preface, for which hearty thanks. I hope to heaven that the book will succeed well enough to prevent you repenting of your aid. This arrival has put the finishing stroke to my conscience, which will endure its wrongs no longer. ... Your article in the "Nation" [March 19] seems to me very good, and you give an excellent idea of Pangenesis--an infant cherished by few as yet, except his tender parent, but which will live a long life. There is parental presumption for you! You give a good slap at my concluding metaphor (A short abstract of the precipice metaphor is given in Volume I. Dr. Gray's criticism on this point is as follows: "But in Mr. Darwin's parallel, to meet the case of nature according to his own view of it, not only the fragments of rock (answering to variation) should fall, but the edifice (answering to natural selection) should rise, irrespective of will or choice!" But my father's parallel demands that natural selection shall be the architect, not the edifice--the question of design only comes in with regard to the form of the building materials.): undoubtedly I ought to have brought in and contrasted natural and artificial selection; but it seems so obvious to me that natural selection depended on contingencies even more complex than those which must have determined the shape of each fragment at the base of my precipice. What I wanted to show was that in reference to pre-ordainment whatever holds good in the formation of a pouter pigeon holds good in the formation of a natural species of pigeon. I cannot see that this is false. If the right variations occurred, and no others, natural selection would be superfluous. A reviewer in an Edinburgh paper, who treats me with profound contempt, says on this subject that Professor Asa Gray could with the greatest ease smash me into little pieces. (The "Daily Review", April 27, 1868. My father has given rather a highly coloured version of the reviewer's remarks: "We doubt not that Professor Asa Gray... could show that natural selection... is simply an instrument in the hands of an omnipotent and omniscient creator." The reviewer goes on to say that the passage in question is a "very melancholy one," and that the theory is the "apotheosis of materialism.") Believe me, my dear Gray, Your ungrateful but sincere friend, CHARLES DARWIN. CHARLES DARWIN TO G. BENTHAM. Down, June 23, 1868. My dear Mr. Bentham,