Weismannism
In regard to almost all the points to which we have referred, the most
consistent and decided champion of Darwinism in its essential principles
is the zoologist of Freiburg, August Weismann.(35) In long chapters on the
protective coloration of animals, on the phenomena of mimicry--that
resemblance to foreign objects (leaves, pieces of wood, bark, and
well-protected animals) by which the mimics secure their own safety from
/>
enemies--on the protective devices in plants, the selective value of "the
useful" is demonstrated. In regard to the marvellous phenomena of
"carnivorous" plants, the still more marvellous instincts of animals,
which cannot be interpreted on Lamarckian lines as "inherited habit," but
only as due to the cumulative influence of selection on inborn tendencies,
as well as in regard to "symbiosis," "the origin of flowers," and so on,
he attempts to show that the heterodox attempts at explanation are
insufficient, and that selection alone really explains. At the same time
the Darwinian principle is carried still further. It is not only among the
individuals, the "persons," that the selective struggle for existence goes
on. Personal selection depends upon a "germinal selection" within the
germ-plasm, influencing it, and being influenced by it--for instance,
restrained.
In order to explain the mystery of heredity, Weismann long ago elaborated,
in his germ-plasm theory, the doctrine that the developing individual is
materially preformed, or rather predetermined in the "idants" and "ids" of
the germ-cell. Thus every one of its physical characters (and, through
these, its psychical characters), down to hairs, skin spots, and
birth-marks, is represented in the "id" by "determinants" which control
the "determinates" in development. In the course of their growth and
development these determinants are subject to diverse influences due to
the position they happen to occupy, to their quality, to changes in the
nutritive conditions, and so on. Through these influences variations in
the determinants may be brought about. And thus there comes about a
"struggle" and a process of selection among the determinants, the result
of which is expressed in changes in the determinates, in the direction of
greater or less development. On this basis Weismann attempts to reach
explanations of the phenomena of variation, of many apparently Lamarckian
phenomena, and of recognised cases of "orthogenesis," and seeks to
complete and deepen Roux's theory of the "struggle of parts," which was
just another attempt to carry Darwinism within the organism.
What distinguishes Weismann, and makes him especially useful for our
present purpose of coming to an understanding in regard to the theory of
selection is, that his views are unified, definite and consistent. In his
case we have not to clear up the ground and to follow things out to their
conclusions, nor to purge his theories from irrelevant, vitalistic, or
pantheistic accessory theories, as we have, for instance, in the case of
Haeckel. His book, too, is kept strictly within its own limits, and does
not attempt to formulate a theory of the universe in general, or even a
new religion on the basis of biological theories. Let us therefore inquire
what has to be said in regard to this clearest and best statement of the
theory of selection when we consider it from the point of view of the
religious conception of the world.
Whatever else may be said as to the all-sufficiency of natural selection
there can be no doubt that it presupposes two absolute mysteries which
defy naturalistic explanation and every other, and which are so important
that in comparison with them the problem of the struggle for efficacy and
its meaning fades into insignificance. These are the functions and
capacities of living organisms in general, and in particular those of
variation and inheritance, of development and self-differentiation. What
is, and whence comes this mysterious power of the organism to build itself
up from the smallest beginnings, from the germ? And the equally mysterious
power of faithfully repeating the type of its ancestors? And, again, of
varying and becoming different from its ancestors? Even the "mechanical"
theory of selection is forced to presuppose the secret of life. Weismann
indeed attempts to solve this riddle through his germ-plasm theory, the
predisposition of the future organism in the "ids," determinants, and
biophors, and through the variation of the determinants in germinal
selection, amphimixis and so on. But this is after all only shifting the
problem to another place, and translating the mystery into algebraical
terms, so to speak, into symbols with which one can calculate and work for
a little, which formulate a definite series of observations, an orderly
sequence of phenomena, which are, however, after all, "unknown quantities"
that explain nothing.
In order to explain the developing organism Weismann assumes that each of
its organs or parts, or "independent regions," is represented in the
germ-plasm by a determinant, upon the fate of which the development of the
future determinate depends. It is thought of as a very minute corpuscle of
living matter. Thus there are determinants of hairs and scales, pieces of
skin, pits, marks, &c. But every determined organ, or part, or
"independent region," is itself in its turn an "organism," is indeed a
system of an infinite number of interrelated component parts, and each of
these again is another, down to the individual cells. And each cell is an
"organism" in itself, and so on into infinity. Is all this represented in
the determinants? And how?
Further, the individual determinate, for instance of a piece of skin, is
not something isolated, but passes over without definite boundary into
others. Therefore the determinants also cannot be isolated, but must be
systems within systems, dependent upon and merging into one another. How,
at the building up of the organism, do the determinants find their
direction and their localisation? And, especially, how do they set to work
to build up their organ? Here the whole riddle of the theory of
epigenesis, which Weismann wished to do away with as a mystery, is
repeated a thousand times and made more difficult. In order to explain
puzzling processes on a large scale, others have been constructed, which
on close investigation prove to be just the same mysterious and
unexplained processes, only made infinitely smaller.
Moreover, even if the whole of "Weismannism," including germinal
selection, could be accepted, and if it were as sufficient as it is
insufficient, what we advanced at the end of Chapter III. as a standpoint
of general validity in relation to teleology and theology would still hold
good. Even an entirely naive, anthropomorphic, "supernatural" theology is
ready to see, in the natural course of things, in the "causae
secundariae," the realisation of Divine purpose, teleology, and does not
fail to recognise that the Divine purpose may fulfil itself not only in an
extraordinary manner, through "miracles" and "unconditioned" events, but
also in ordinary ways, "through means" and the universal causal nexus.
Thus it is quite consistent even with a theology of this kind to regard
the whole system of causes and effects, which, according to the
Darwin-Weismann doctrine, have gradually brought forth the whole diversity
of the world of life, with man at its head, in a purely causal way without
teleological intervention, as an immense system of means marvellous in its
intricacy, in the inevitable necessity of its inter-relations, and in the
exactness of its work, the ultimate result of which must have come
about, but perhaps at the same time was intended to come about. Whether
I regard this ultimate result as the mere consequence of blind happenings,
or as an intended purpose, does not depend, as we have seen, upon the
knowledge gained by natural science, but depends above all on whether this
ultimate result seems to me of sufficient value to be thought of as the
purpose of a world-governing intelligence, and thus depends upon my
personal attitude to human nature, reason, mind, and the spiritual,
religious, and moral life. If I venture to attribute worth, and absolute
worth, to these things, nothing, not even the fact of the "struggle for
existence" in its thousand forms, in its gradually transforming effects,
in the almost endless nexus of its causes and results, germinal selection
included, can take away my right (and eventually my duty) to regard the
ultimate result as an end, and the nexus of causes as a system of means.
To enable me to do this, it is only requisite that internal necessity
should govern the system, and that the result should not be a chance one,
so that it might even have been suppressed, have failed, or have turned
out quite differently. Necessity and predetermination are characteristic
of the relation between means and purpose. But this requisite is precisely
that which natural science does afford us,--namely, the proof that all
phenomena are strictly governed by law, and are absolutely predetermined
by their antecedents. At this point the religious and the scientific
consideration coincide exactly. The hairs of our head, and the hairs in
the fur of a polar bear, which is varying towards white, and is therefore
selected in the struggle for existence,(36) even the fluctuating
variations of a determinant in the germ, are "numbered" according to both
conceptions. Every variation that cropped up, every factor that "selected"
the fit, and eliminated the unfit, was strictly predestined, and must of
necessity have appeared as, and when, and where it did appear.(37)
The whole nexus of conditions and results, the inclined plane of evolution
and the power of Being to move up it, has its sufficient reason in the
nature and original state of the cosmos, in the constitution of its
"matter," its "energy," its laws, its sequences and the grouping of its
phenomena. Only from beginnings so constituted could our present world
have come to be as it is, and that necessarily. Only because the primary
possibility and fitness for life--vegetable, animal and human--was in it
from the beginning, could all these have come to be. This primary
possibility did not "come into being," it was a priori immanent in it.
Whence came this? There is no logical, comprehensible, or any other
necessity why there should be a world at all, or why it should be such
that life and evolution must become part of it. Where then lies the reason
why it is, rather than is not, and why it is as it is?
To this must be added what Weismann himself readily admits and expressly
emphasises. The whole theory treats, and must treat plant, animal, and man
as only ingenious machines, mere systems of physical processes. This is
the ideal aimed at--to interpret all the phenomena of life, growth, and
reproduction thus. Even instincts and mental endowments are so
interpreted, since there must be corresponding morphological variations of
the fine structure of the nervous organ, and instinctive actions are then
"explained" as the functions of these. But how "mechanical happening"
comes to have this marvellous inwardness, which we call sensation,
feeling, perception, thought and will, which is neither mechanical nor
derivable from anything mechanical; and, further, how physical and
psychical can condition one another without doing violence to the law of
the conservation of the sum of energy, is an absolute riddle. But this
whole psychical world exists, with graduated stages perhaps as close to
each other as in the physical world, but even less capable than these of
being explained as having arisen out of their antecedent lower stages. And
this psychical world, which is, indeed, related to and dependent upon the
corporeal life, as also conversely, has its own quite peculiar laws:
thought does not follow natural laws, but those of logic, which is
entirely indifferent to exciting stimuli, for instance of the brain, which
conform to natural laws. But this world, its riddles and mysteries, its
great content and its history, beyond the reach of mechanical theories, is
so absolutely the main thing (especially in regard to the question of the
possibility of religion), that the question of bodily structure and
evolution becomes beside it a mere accessory problem, and even the last is
only a relatively unimportant roundabout way of coming at the gist of the
business. How completely the evolution of the higher mental faculties
transcends such narrow and meagre formulae as the struggle for existence
and the like, Weismann himself indicates in connection with man's musical
sense, and its relation to the "musical" instinct in animals. The same and
much more might be alleged in regard to the whole world of mind, of the
aesthetic, ethical and religious, of the kingdom of thought, of science,
and of poetry.