My dear Lyell

You seem to have worked admirably on species-question: there could not have been better plan than reading up on opposed side. I rejoice profoundly that you intend admitting doctrine of modification in your new Edition.¹ Nothing, I am convinced, could be more important for its success. I honour you most sincerely:—to have maintained, in the position of a master, one side of a question for 30 years & then deliberately give it up, is a fact, to which I much doubt whether the records of science offer a parallel. For myself, also, I rejoice profoundly; for thinking of the many cases of men pursuing an illusion for years, often & often a cold shudder has run through me & I have asked myself whether I may not have devoted my life to a phantasy. Now I look at it as morally impossible that investigators of truth like you & Hooker can be wholly wrong; & therefore I feel that I may rest in peace.

Thank you for criticisms, which, if there be 2^d. Edit. I will attend to.² I have been thinking that if I am much execrated as atheist &c, whether the admission of doctrine of natural Selection could injure your Works; but I hope & think not; for as far as I can remember the virulence of bigotry is expended on first offender, & those who adopt his views are only pitied, as deluded, by the wise & cheerful bigots.—

I cannot help thinking that you overrate importance of multiple origin of dogs.³ The only difference is that in case of single origin all difference of the races has originated since man domesticated the species; in the case of multiple origin part of difference was produced under natural conditions.—

I sh^d infinitely prefer the theory of single origin in all cases; if facts would permit its reception. But there seems to me some a priori improbability, (seeing how fond savages are of taming animals) that througout all time & througout all the world, that man sh^d have domesticated one single species alone of the widely-distributed genus Canis. Besides this the close resemblance of at least three kinds of American domestic dogs, to wild species still inhabiting the countries where they are now domesticated, seems to almost compel admission that more than one wild Canis has been domesticated by man.—

I thank you cordially for all the generous zeal & interest you have shown about my Book & I remain my dear Lyell | Your affect friend & disciple | Charles Darwin

Sir J. Herschel, to whom I sent copy, is going to read my Book.⁴ He says he leans to side opposed to me. If you sh^d. meet him, after he has read me, pray find out what he thinks. For of course he will not write; & I sh^d excessively like to hear whether I produce any effect on such a mind.⁵