science. But what makes me most object to Asa Gray's view is the study of
the extreme variability of domestic animals. He who does not suppose that
each variation in the pigeon was providentially caused, by accumulating
which variations, man made a Fantail, cannot, I think, logically argue that
the tail of the woodpecker was formed by variations providentially
ordained. It seems to me that variations in the domestic and wild
conditions are due to unknown causes, and are without purpose, and in so
far accidental; and that they become purposeful only when they are selected
by man for his pleasure, or by what we call Natural Selection in the
struggle for life, and under changing conditions. I do not wish to say
that God did not foresee everything which would ensue; but here comes very
nearly the same sort of wretched imbroglio as between freewill and
preordained necessity. I doubt whether I have made what I think clear; but
certainly A. Gray's notion of the courses of variation having been led like
a stream of water by gravity, seems to me to smash the whole affair. It
reminds me of a Spaniard whom I told I was trying to make out how the
Cordillera was formed; and he answered me that it was useless, for "God
made them." It may be said that God foresaw how they would be made. I
wonder whether Herschel would say that you ought always to give the higher
providential law, and declare that God had ordered all certain changes of
level, that certain mountains should arise. I must think that such views
of Asa Gray and Herschel merely show that the subject in their minds is in
Comte's theological stage of science...

Of course I do not want any answer to my quasi-theological discussion, but
only for you to think of my notions, if you understand them.

I hope to Heaven your long and great labours on your new edition are
drawing to a close.