g, insuperable doubts arise
as to how we can explain from two causes the world of organisms which is so
richly, beautifully, and systematically arranged. The first of these causes
is the inclination to individual alteration, inherited indeed in the
organisms, but in itself absolutely indifferent, for the systematical idea
in the framework of the organic systems and for the progressive element in
the development. The other is the struggle for existence and natural
selection, which approaches the organisms purely from without like
individual variability, must as a whole appear a necessity, but in each
single case in the concrete mixture of coinciding circumstances, would seem
a work of chance for the individual which is to be changed.

Moreover, it is a demonstrable impossibility to explain the origin of just
those organs and members in the structure of organisms which are
systematically the most significant and functionally the most important, by
means of natural selection. It is true that many of these organs and
members, in their perfected state, offer to the organism an immense
advantage over lower organisms; but if they had been originated through
gradual development, they would have been in their first {105} beginnings
and earlier stages of development at least quite indifferent, often
directly obstructive to the individual in its struggle for existence, and
therefore would have been called into existence and developed by agencies
which had an effect directly counteracting natural selection. How high, for
instance, stand the vertebrates above the invertebrates! Yet how could the
first deviation from the ganglionic system of the nerves of the
invertebrates to the cerebro-spinal system of the vertebrates have
occurred?--and, especially, how could the first deposit of the vertebral
column have procured any benefit to the individual in the struggle for
existence? We quote this objection from Karl Planck's "Wahrheit und
Flachheit des Darwinismus," ("Truth and Platitude of Darwinism"),
Noerdlingen, Beck, 1872.

Still more striking is the insufficiency of the selection theory for the
explanation of the origin of the organs of motion in the higher classes of
vertebrates. A. W. Volkman says of it, in his instructive lecture, "Zur
Entwickelung der Organismen," ("Development of the Organisms") Halle,
Schmidt, 1875, p. 3 ff.: "Without doubt, animals with extremities will come
from animals which lacked extremities. Now if the me