Dr. Parry passed last summer in the Colorado Rocky Mountains, where Madame and I visited him, in his cabin; and we ascended Gray’s Peak together (14,400 feet). Torrey, old as he is, was there later, but did not get up the twin Torrey’s Peak, though his daughter did surmount Gray’s Peak....
Now about myself. In what time I can save I am assisting Brewer in the “Flora of California,” and shall do for him the Monopetalæ, and finish next summer, if my health does not fail.
Moreover, this is my last year of university work. I finish in July, and then resign, and give my remaining time to the “Flora of North America.” Although it is so arranged, it is not yet to be announced. It is difficult to drop at once the many things I have charge of, and the vast correspondence all over the country, which has been very useful to me, and others, but which takes a deal of time. But I am making a fairly good beginning. Mrs. Gray delights with me in the prospect of release from many a care, and of devoting myself without distraction to the work I have always liked best.
I really hope it is not too late to do something (a few lines from you upon this subject might, _entre nous_, be useful to me).
... I cannot object to your maintaining the hypothesis that each and every existing plant and animal form has been directly created (or mediately created, if you see a difference) out of the soil, pure hypothesis though it be, and one which “from the nature of the case can never be directly proved.” It is natural that you should hold to such hypothesis as long as you believe it to be possibly tenable.
But what I may ask you very seriously to consider is, whether you are prepared to bear the responsibility you assume in maintaining and teaching that no hypothesis of the derivation of existing “specific” forms from previous ones more or less like them can logically be theistic and religious. How far any such hypothesis may be probable or tenable in view of the evidence is not the question raised, but a far more momentous one.
Consider what the “younger men who learn of you” will be likely to think when they come to discard, as the best informed ones probably will after a while, your scientific views on this subject; but still, perchance, confide in your dictum that the doctrine of the derivative origin of one species from another cannot logically stop short of “blank materialism, destructive both of science and religion, and even ... to morals and social organization.”