Apart from its intrinsic merit the work keenly excited his sympathy from the conditions under which it was executed, Mr. Mackintosh being compelled to give nearly his whole time to tuition. The following passage is from a letter to Mr. Mackintosh of October 9, 1879, and refers to his paper in the Journal of the Geological Society, 1878:--
"I hope that you will allow me to have the pleasure of thanking you for the very great pleasure which I have derived from just reading your paper on erratic blocks. The map is wonderful, and what labour each of those lines show! I have thought for some years that the agency of floating ice, which nearly half a century ago was overrated, has of late been underrated. You are the sole man who has ever noticed the distinction suggested by me (In his paper on the 'Ancient Glaciers of Carnarvonshire,' Phil. Mag. xxi. 1842.) between flat or planed scored rocks, and mammillated scored rocks."]
CHARLES DARWIN TO C. RIDLEY. Down, November 28, 1878.
Dear Sir,
I just skimmed through Dr. Pusey's sermon, as published in the "Guardian", but it did [not] seem to me worthy of any attention. As I have never answered criticisms excepting those made by scientific men, I am not willing that this letter should be published; but I have no objection to your saying that you sent me the three questions, and that I answered that Dr. Pusey was mistaken in imagining that I wrote the 'Origin' with any relation whatever to Theology. I should have thought that this would have been evident to any one who had taken the trouble to read the book, more especially as in the opening lines of the introduction I specify how the subject arose in my mind. This answer disposes of your two other questions; but I may add that many years ago, when I was collecting facts for the 'Origin,' my belief in what is called a personal God was as firm as that of Dr. Pusey himself, and as to the eternity of matter I have never troubled myself about such insoluble questions. Dr. Pusey's attack will be as powerless to retard by a day the belief in Evolution, as were the virulent attacks made by divines fifty years ago against Geology, and the still older ones of the Catholic Church against Galileo, for the public is wise enough always to follow Scientific men when they agree on any subject; and now there is almost complete unanimity amongst Biologists about Evolution, though there is still considerable difference as to the means, such as how far natural selection has acted, and how far external conditions, or whether there exists some mysterious innate tendency to perfectability. I remain, dear Sir,
Yours faithfully, CH. DARWIN.
[Theologians were not the only adversaries of freedom in science. On September 22, 1877, Prof. Virchow delivered an address at the Munich meeting of German Naturalists and Physicians, which had the effect of connecting Socialism with the Descent theory. This point of view was taken up by anti-evolutionists to such an extent that, according to Haeckel, the "Kreuz Zeitung" threw "all the blame of" the "treasonable attempts of the democrats Hodel and Nobiling...directly on the theory of Descent." Prof. Haeckel replied with vigour and ability in his 'Freedom in Science and Teaching' (English Translation 1879), an essay which must have the sympathy of all lovers of freedom.
The following passage from a letter (December 26, 1879) to Dr. Scherzer, the author of the 'Voyage of the "Novara",' gives a hint of my father's views on this once burning question:--
"What a foolish idea seems to prevail in Germany on the connection between Socialism and Evolution through Natural Selection."]
CHARLES DARWIN TO H.N. MOSELEY. (Professor of Zoology at Oxford. The book alluded to is Prof. Moseley's 'Notes by a Naturalist on the "Challenger".') Down, January 20, 1879.
Dear Moseley,
I have just received your book, and I declare that never in my life have I seen a dedication which I admired so much. ("To Charles Darwin, Esquire, LL.D., F.R.S., etc., from the study of whose 'Journal of Researches' I mainly derived my desire to travel round the world; to the development of whose theory I owe the principal pleasures and interests of my life, and who has personally given me much kindly encouragement in the prosecution of my studies, this book is, by permission, gratefully dedicated.") Of course I am not a fair judge, but I hope that I speak dispassionately, though you have touched me in my very tenderest point, by saying that my old Journal mainly gave you the wish to travel as a Naturalist.