. It is
the fate of every idea which is new and fruitful, that it is ridden to the
death by excited novices. We can not be surprised if this fate has
overtaken the idea that all existing animal forms have had their ancestry
in other forms which exist no longer, and have been derived from these by
ordinary generation through countless stages of descent. Although this is
an idea which, whether true or not, is entirely subordinate to the larger
idea of creation, it usurps in many minds the character of a substitute.
This is natural enough. The theory, or at least the language, of
Evolutionists, puts forward a visible order of phenomena as a complete and
all-sufficient account of its own origin and cause. However unsatisfactory
this may be to the higher faculties of the mind, it is eminently {6}
satisfactory to those other faculties which are lower in the scale. It
dismisses as needless, or it postpones indefinitely, all thought of the
agencies which are ultimate and unseen. Just as in the physical world, some
trivial object which is very near us may shut out the whole of a wide
horizon, so in the intellectual world, some coarse mechanical conception
may shut out all the kingdom of Nature and the glory of it.

Two great subjects of investigation lie before us. The first is to
ascertain how far the Theory of Evolution represents an universal fact, or
only one very partial and fragmentary aspect of a great variety of facts
connected with the origin and development of Organic Life. The second and
by far the most important inquiry, is to estimate aright, or as nearly as
we can, the relative place and importance of these facts in the Philosophy
of Nature.

Subjects of investigation so rich and manifold as these may well attract
all the most varied gifts of the human mind. This they have already done,
and there is every indication that they will continue to do so for
generations yet to be. Already an immense literature is devoted to them;
and every fresh effort of observation and of reasoning seems to open out
new and fruitful avenues of thought. The work which is here introduced to
the English reader contains an excellent review of this literature, so far
as it is represented in the English and German languages. Knowing the
author personally, as I have done for many years, I recognize with pleasure
in his work all the carefulness of inquiry, and all the conscientiousness
of reasoning, which belong to a singularly candid and pati