I shall perhaps best promote the acceptance of the two main points
on which I have been insisting for some years past, I mean, the
substantial identity between heredity and memory, and the
reintroduction of design into organic development, by treating them
as if they had something of that physical life with which they are
so closely connected. Ideas are like plants and animals in this
respect also, as in so many others, that they are more fully
understood when their relations to other ideas of their time, and
the history of their development are known and borne in mind. By
development I do not merely mean their growth in the minds of those
who first advanced them, but that larger development which consists
in their subsequent good or evil fortunes--in their reception,
favourable or otherwise, by those to whom they were presented. This
is to an idea what its surroundings are to an organism, and throws
much the same light upon it that knowledge of the conditions under
which an organism lives throws upon the organism itself. I shall,
therefore, begin this new work with a few remarks about its
predecessors.

I am aware that what I may say on this head is likely to prove more
interesting to future students of the literature of descent than to
my immediate public, but any book that desires to see out a literary
three-score years and ten must offer something to future generations
as well as to its own. It is a condition of its survival that it
shall do this, and herein lies one of the author's chief
difficulties. If books only lived as long as men and women, we
should know better how to grow them; as matters stand, however, the
author lives for one or two generations, whom he comes in the end to
understand fairly well, while the book, if reasonable pains have