(Chap. XII.); (6) some new illustrations of the non-heredity of acquired
characters, and a proof that the effects of use and disuse, even if
inherited, must be overpowered by Natural Selection (Chap. XIV.); and
(7) a new argument as to the nature and origin of the moral and
intellectual faculties of man (Chap. XV.).

"Although I maintain, and even enforce," wrote Wallace, "my differences
from some of Darwin's views, my whole work tends forcibly to illustrate
the overwhelming importance of Natural Selection over all other agencies
in the production of new species. I thus take up Darwin's earlier
position, from which he somewhat receded in the later editions of his
works, on account of criticisms and objections which I have endeavoured
to show are unsound. Even in rejecting that phase of sexual selection
depending on female choice, I insist on the greater efficacy of Natural
Selection. This is pre-eminently the Darwinian doctrine, and I therefore
claim for my book the position of being the advocate of pure Darwinism."

In concluding this section which, like a previous one, touches upon the
intimate relations between Darwin and Wallace, and the points on which
they agreed or differed, it is well, as the differences have been
exaggerated and misunderstood, to bear in mind his own declaration:
"None of my differences from Darwin imply any real divergence as to the
overwhelming importance of the great principle of natural selection,
while in several directions I believe that I have extended and
strengthened it."[8]

With these explanatory notes the reader will now be able to follow the
two groups of letters on Natural Selection, Geographical Distribution,
and the Origin of Life and Consciousness which follow.