To G. H. K. Thwaites 21 March 1
Down Bromley Kent
My dear Mr. Thwaites
I thank you very sincerely for your letter & am much pleased that you go a little way with me.2 You will think it presumptuous, but I am well convinced from my own mental experience, that if you keep the subject at all before your mind, you will ultimately go further. The present vol. is mere abstract & there are great omissions— one main one, which I have rectified in the foreign Editions is an explanation (which has satisfied Lyell, who made same objection with you) why many forms do not progress or advance.3 (& I quite agree about some retrograding)— I have also M.S. discussion on beauty—but do you really suppose that for instance Diatomaceæ were created beautiful that man after millions of generations shd. admire them through the microscope?—4
I shd. attribute most of such structures to quite unknown laws of growth; & mere repetition of parts is to our eyes one main element of beauty. When any structure is of use (& I can show what curiously minute particulars are often of highest use) I can see with my prejudiced eyes no limit to the perfection of the coadaptations which could be effected by natural selection.—
I rather doubt whether you see how far, as it seems to me, the argument from Homology & Embryology may be carried. I do not look at this as mere analogy. I would as soon believe that fossil shells were mere mockeries of real shells, as that the same bones in foot of dog & wing of bat—or the similar embryo of mammal & bird—had not a direct signification & that signification can be unity of descent or nothing. But I venture to repeat how much pleased I am that you go some little way with me. I find a number of naturalists do the same, & as their halting places are various & I must think arbitrary, I believe they will all go further. As for changing at once ones opinion; I would not value the opinion of a man who could do so: it must be a slow process.—
Thank you for telling me about the Lantana;5 & I shd. at any time be most grateful for any information which you think would be of use to me.— I hope that you will publish a list of all naturalised plants in Ceylon, as far as known, carefully distinguishing those confined to cultivated soils alone. I feel sure that this most important subject has been greatly undervalued.
With hearty thanks for your letter | Believe me | Yours very sincerely | C. Darwin
Is pleased GHKT goes a little way with him.
Has rectified in foreign editions of Origin his omission of an explanation of the failure of many forms to progress;
also has discussion of beauty in MS. Does GHKT really believe Diatomaceae, for instance, were created beautiful so that man, millions of generations later, should admire them through a microscope? CD attributes most of these structures to unknown laws of growth; useful structures are accounted for by natural selection.
- Letter no.
- Darwin, C. R.
- Thwaites, G. H. K.
- Sent from
- Source of text
- Smithsonian Institution Libraries (Special collections)
- Physical description
Please cite as
Darwin Correspondence Project, “Letter no. 2731,” accessed on 5 December 2016, http://www.darwinproject.ac.uk/DCP-LETT-2731