share the sovereignty with the idea
of origin by leaps through metamorphosis of germs. Still more unfavorable
is the state of the selection theory. It possesses the merit of having
started the whole question as to the origin of species; it may explain
subordinary developments; natural selection may have cooeperated as a
regulator in the whole progress and the whole preservation of organic life.
Ed. von Hartmann, in his essay, "Truth and Error of Darwinism," (Berlin,
Duncker, 1875), on page 111, compares its functions with those of the bolt
and coupling in a machine; but that the driving principle which called new
species into existence lay or originated _in_ the organisms, and did not
approach them from without, seems to be confirmed more and more decidedly
with every new step of exact investigation as well as of reflection.

* * * * * {108}

BOOK II.

THE PHILOSOPHIC SUPPLEMENTS AND CONSEQUENCES OF THE DARWINIAN THEORIES.

* * * * *

THE PHILOSOPHIC PROBLEMS.

Although, in accordance with the requirements of the task before us, we
have to restrict ourselves to giving the results of natural science only in
their general outlines, still we believe that we have not overlooked any
essential result which is of importance to the question of the origin of
species and of man. We have now finished our scientific review; and the
conclusion to which we see ourselves brought is that natural science, in
its investigation of the origin of species, has arrived at nothing but
problems which it is not able to solve. There is a very great probability
of an origin of species, at least of the higher organized species, through
descent; but whether through descent by means of gradual development or of
metamorphosis of germs, or whether with one group of organisms it is in
this way, with another in that, is not yet decided. The attempt to explain
their entire origin exclusively by the selection theory, must be regarded
as a failure; all indications rather show that, supposing the descent
principle correct, the deciding agencies which formed new species did not
approach the old species out of which the new ones originated from {109}
without, but that they originated or were already in existence within them.
But what these agencies were, natural science is at present unable to
state; and not only those scientists who reject every idea of a descent,
but also those who are favo