My dear Lyell

I have endeavoured to think over your discussion, but not with much success.— I, of course, see that if you can make out your argument satisfactorily to yourself & others it would be most valuable.—   You will have to lay down, I think, very clearly on what foundation you argue from 4 parts (which seems to me exceedingly moderate on your part) of Europe being now at rest, with 1 part undergoing movement, how it is that from this that you can argue that the one part which is now moving will have rested since the commencement of Glacial period in the proportion of four to one—   I do not pretend to see with any clearness, but does not your argument rest on the assumption, that within a given period, say two or 3 million years, that the whole of Europe necessarily has to undergo movement.—   This may be probable or not so, but it seems to me that you must explain the foundation of your argument from space to time,—which at first to me was very far from obvious.

I can imagine some one saying that it is not fair to argue that the great plains of Europe & the mountainous districts of Scotland & Wales have been at all subjected to same laws of movement.

Looking to the whole world it has been my opinion, from the very size of the continents & oceans, & especially from the enormous ranges of so many mountain-chains (resulting from cracks which follow from vast areas of elevation as Hopkins argues)¹ & from other reasons, it has been my opinion that as a general rule very large portions of the world have been simultaneously affected by elevation or subsidence.— I can see that this does not apply so strongly to broken Europe any more that to the Malay Archipelago. Yet had I been asked, I sh^d have said that probably nearly the whole of Europe was subjected, during the Glacial period, to periods of elevation & of subsidence. It does not seem to me so certain that the kinds of partial movements which we now see going on show us the kind of movement which Europe has been subjected to since the commencement of Glacial period.—

These notions are at least possible, & would they not vitiate your argument? Do you not rest on belief that as Scandinavia & some few other parts are now rising, & a few others sinking, & the remainder at rest; that so it has been since the commencement of the Glacial period.— With my notions, I sh^d. require this to be made pretty probable before I could put much confidence on your calculations— You have probably thought this all over; but I give you the reflexions which come across me, supposing for the moment, that you took the proportion of space at rest & in movement, as as plainly applicable to time.—   I have no doubt that you have sufficient evidence that at the commencement of the Glacial period the land in Scotland, Wales &c stood as high or higher than at present; but I forget the proofs.—

Having burnt my own fingers so consumedly with the Wealden,² I am fearful for you; but I well know how infinitely more cautious, prudent & far-seeing you are than I am.— But for Heaven-sake take care of your fingers; to burn them severely, as I have done, is very unpleasant.—

Your 2$\frac{1}{2}$ feet per century of elevation seems a very handsome allowance. Can D. Forbes really show that great elevation of Chile: I am astounded at it, & I took some pains on point.— ³

I do not pretend to say that you may not be right to judge of the past movements of Europe by those now & recently going on, yet it somehow grates against my judgment,—perhaps only against my prejudices.—

My dear Lyell | Yours affec^t | C. Darwin

P.S. | I do not know whether I have made clear, what I think probable or at least possible; viz that the greater part of Europe has at times been elevated in some degree equably; at other times it has all subsided equally; & at other times might all have been stationary; & at other times it has been subjected to various unequal movements, up & down, as at present.—   As a change from elevation to subsidence implies some great subterranean or cosmical change, one may surely calculate on long interval of rest between. Though if cause of change be ever proved to be astronomical even this might be doubtful.