the naturo-philosophical and metaphysical
supplements and conclusions which have been brought into connection with
them. For precisely in the mixing of the most different problems which are
to be considered here, lies the main cause of the confused and superficial
judgment which is so often heard upon these questions.

* * * * * {21}

PART I.

* * * * *

THE THEORIES OF DARWIN.

* * * * *

{23}

BOOK I.

THE PURELY SCIENTIFIC THEORIES.

* * * * *

THE SCIENTIFIC PROBLEM.

The interesting problem which underlies Mr. Darwin's theories is the answer
to the question: _How did the different species of organic beings on the
earth originate?_ We find ourselves in the midst of an endless variety of
organic beings, animals and plants; we see ourselves, so far as regards the
entire physical part of our being, in relationship with this organic
world--especially with the organization and physical functions of the
animal body. The organic individuals come and go. They originate by being
begotten by and born of individuals of the same kind, or they spring up
through the formation of germs and buds; and they produce in the same way
new individuals, that resemble them in all essential characteristics. Like
always begets like, so far as our observations go. But not only the
individuals, but even the species to which they belong, must have
originated at some definite period of time--and, indeed, as geology tells
us, not all at once, but in a long series, which stretched through
immeasurable epochs of the earth's history. Thus we come face to face with
the question, already put, which we can now formulate more {24} precisely:
_How did the first individuals of each organic species come into
existence?_

No human being ever has observed, nor ever could observe, the origination
of a new species, because man, as it seems, did not appear on the earth
until all the other organisms were in existence. For this reason, the
scientists for a long time thought it unprofitable to occupy themselves
with this question; and even in our time a great many of them declare the
question to be absolutely insolvable, and every attempt at answering it to
be an unjustifiable use of hypotheses. But the impulse toward investigation
admits of no limitation so long as there is any probability of extending
its field of action