In seeking to define our position in regard to the theory of descent it is
most important that we should recognise that, when it is looked into
closely, the true problem at issue is not a special zoological one, but is
quite general, and also that it is not a new growth which has sprung up
suddenly and found us unprepared, but that it is very ancient and has long
existed in our midst. In the whole theory the question of “descent” is
after all a mere accessory. Even if it fell through and were seen to be
scientifically undemonstrable, “evolution in the realm of life” would
remain an indisputable fact, and with it there would arise precisely the
same difficulties for the religious interpretation of the world which are
usually attributed to the Theory of Descent.
Evolution or development has been a prominent idea in the history of
thought since the time of Aristotle, but descent is, so to speak, a modern
upstart. According to long-established modes of thought, to _evolve_ means
to pass from δυνάμει to ἰνεργεία εἴναι, from _potentia_ to _actus_, from
the existence of the rudiment as in the seed to full realisation as in the
tree. In the course of its development the organism passes through many
successive phases, which are related to one another like steps, each
rising directly from the one beneath, and preparing for the one above.
Thus all nature, and especially the realm of life, implies a ladder of
“evolution.” What is “potentially” inherent in the lowest form of life has
in the highest, as in man, become actual or “realised” through a
continuous sequence of phases, successively more and more evolved. This
view in its earlier forms was very far from implying that each higher step
was literally “descended” from the one below it, through the physical and
mental transformation of some of its representatives. As the world, in
Aristotle’s view for instance, had existed from all eternity, so also had
the stages and forms of life, each giving rise again to its like. Indeed,
the essential idea was that each higher step is simply a development, a
fuller unfolding of the lower stage, and finally that man was the complete
realisation of what was potentially inherent in the lowest of all.
This doctrine of evolution was in modern times the fundamental idea of
Leibnitz and Kant, of Goethe, Schelling and Hegel. It brought unity and
connectedness into the system of nature, united everything by steps,
denied the existence of gaping chasms, and proclaimed the solidarity of
all the forms of life. But to all this the idea of actual descent was
unnecessary. An actual material variation and transition from one stage to
another seemed to it a wooden and gross expression of the evolution idea,
an “all too childish and nebulous hypothesis” (Hegel).
All the important results of comparative morphology and physiology, which
the modern supporters of the doctrine of descent so confidently utilise as
arguments in its favour, would have been welcomed by those who held the
original and general evolution idea, as a corroboration of their own
standpoint. And as a matter of fact they all afford conclusive proofs of
_evolution_; but not one of them, including even the fundamental
biogenetic law and the inoculated chimpanzee, is decisive in regard to
_descent_. This contention is sufficiently important to claim our
attention for a little. Let us take the last example. Transfusion of blood
between two species is possible, not necessarily because they are
descended from one another or from a common root, but solely because of
their systematic (ideal) relationship, that is to say because they are
sufficiently near to one another and like one another in their
physiological qualities and functions. If, assuming descent, this homology
were disturbed, and the systematic relationship done away with, for
instance through saltatory evolution, the mere fact of descent would not
bring the two species any nearer one another. Thus the case proves only
systematic relationship, and only evolution. But as to the meaning of this
systematic relationship, whether it can be “explained” by descent, whether
it has existed from all eternity, or how it has arisen, the experiment
does not inform us.
The same idea may be illustrated in regard to Weismann’s “predicting.”
This, too, is a proof of evolution, but not of descent. Exactly as
Weismann predicted the striping of the hawk-moth caterpillars and the
human _os centrale_, Goethe predicted the formation of the skull from
modified vertebræ, and the premaxillary bone in man. In precisely the same
way he “derived” the cavities in the human skull from those of the animal
skull. This was quite in keeping with the manner and style of his Goddess
Nature and her creative transformations, raising the type of her creations
from stage to stage, developing and expanding each new type from an
earlier one, yet keeping the later analogous to and recapitulative of the
earlier, recording the earlier by means of vestigial and gradually
dwindling parts.
But what has all this to do with descent? Even the “biogenetic law”
itself, especially if it were correct, would fit admirably into the frame
of the pure evolution idea. For it is quite consistent with that idea to
say that the higher type in the course of its development, especially in
its embryonic stages, passes through stages representative of the forms of
life which are below it and precede it in the (ideal) genealogical tree.
Indeed, the older doctrine of evolution took account of this long ago.
“The same step-ladder which is exhibited by the whole animal kingdom, the
steps of which are the different races and classes, with at the one
extreme the lowliest animals and at the other the highest, is exhibited
also by every higher animal in its development, since from the moment of
its origin until it has reached its full development it passes
through—both as regards internal and external organisation—the essentials
of all the forms which become permanent for a lifetime in the animals
lower than itself. The more perfect the animal is, the longer is the
series of forms it passes through.”
So J. Fr. Meckel wrote in 1812 in his “Handbook of Pathological Anatomy,”
_with no thought of descent_. And the facts which led to the construction
of the biogenetic law were discovered in no small measure by Agassiz, who
was an opponent of the doctrine of descent.(31)
But the advance from the doctrine of evolution to that of descent was
imperatively prompted by a recognition of the fact that the earth is not
from everlasting, and that the forms of life upon it are likewise not from
everlasting, that, in fact, their several grades appear in an orderly
ascending series. It is therefore simpler and more plausible to suppose
that each higher step has arisen from the one before it, than to suppose
that each has, so to speak, begun an evolution on its own account. A
series of corroborative arguments might be adduced, and there is no doubt,
as we have said before, that the transition from the general idea of
evolution to that of descent will be fully accomplished. But it is plain
that the special idea of descent contributes nothing essentially new on
the subject.
It is an oft-repeated and self-evident statement, that it is in reality a
matter of entire indifference whether man arose from the dust of the earth
or from living matter already formed, or, let us say, from one of the
higher vertebrates. The question still would be, how much or how little of
any of them does he still retain, and how far does he differ from all?
Even if there be really descent, the difference may quite as well be so
great—for instance, through saltatory development—that man, in spite of
physical relationship, might belong to quite a new category far
transcending all his ancestors in his intellectual characteristics, in his
emotional and moral qualities. There is nothing against the assumption,
and there is much to be said in its favour, that the last step from animal
to man was such an immense one that it brought with it a freedom and
richness of psychical life incomparable with anything that had gone
before—as if life here realised itself for the first time in very truth,
and made everything that previously had been a mere preliminary play.
On the other hand, even were there no descent but separate individual
creation, man might, in virtue of his ideal relationship and evolution,
appear nothing more than a stage relatively separate from those beneath
him in evolution. It was not the doctrine of descent, it was the doctrine
of evolution that first ranked man in a series with the rest of creation,
and regarded him as the development of what is beneath him and leads up to
him through a gradual sequence of stages. And his nearness, analogy, or
relationship to what is beneath him is in no way increased by descent, or
rendered a whit more intimate or more disturbing.
The Problema Continui.
The problem of descent thus shows itself to be one which has neither
isolated character nor special value. It is an accessory accompaniment of
all the questions and problems which have been raised by, or are
associated with, the doctrine of evolution, which would have been in our
midst without Darwin, which are made neither easier nor more difficult by
zoological knowledge, and the difficulties of which, if solved, would
solve at the same time any difficulties presented by descent. The
following considerations will serve to make this clear. The most
oppressive corollary of the doctrine of descent is undoubtedly that
through it the human race seems to become lost in the infra-human, from
which it cannot be separated by any hard and fast boundaries, or absolute
lines of demarcation. But it is easy to see that this problem is in fact
only a part of a larger problem, and that it can really be solved only
through the larger one. Even if it were possible to do away with this
unpleasing inference as regards the whole human race, so that it could be
in some way separated off securely from the animal kingdom, the same
fatality would remain in regard to each individual human being. For we
have here to face the problem of individual development by easy
transitions, the ascent from the animal to the human state, and the
question: When is there really soul and spirit, when man and ego, when
freedom and responsibility? But this is the same problem again, only
written with smaller letters, the general _problema continui_ in the
domain of life and mind. And the problem is very far-reaching. In all
questions concerning mental health and disease, abnormalities or cases of
arrest at an early stage of mental development, concerning the greater or
less degree of endowment for intellectual, moral, and religious life, down
to utter absence of capacity, and this in relation to individuals as well
as races and peoples, and times; and again, concerning the gradual
development of the ethical and religious consciousness in the long course
of history, in its continuity and gradual transition from lower to higher
forms: everywhere we meet this same _problema continui_. And our
oppressive difficulty is bound up with this problem, and can be dispelled
only by its solution, for the gist of the difficulty is nothing else than
the _gradualness of human becoming_.
This is not the place for a thoroughgoing discussion of this _problema
continui_. We can only call to mind here that the “evolution idea” has
been the doctrine of the great philosophical systems from Aristotle to
Leibnitz, and of the great German idealist philosophers, in whose school
the religious interpretation of the world is at home. We may briefly
emphasise the most important considerations to be kept in mind in forming
a judgment as to gradual development.
1. To recognise anything as in course of evolving does not mean that we
understand its “becoming.” The true inwardness of “becoming” is hidden in
the mystery of the transcendental.
2. The gradual origin of the highest and most perfect from the primitive
in no way affects the specific character, the uniqueness and newness of
the highest stage, when compared with its antecedents. For, close as each
step is to the one below, and directly as it seems to arise out of it,
each higher step has a minimum and differentia of newness (or at least an
individual grouping of the elements of the old), which the preceding stage
does not explain, or for which it is not a sufficient reason, but which
emerges as new from the very heart of things.
3. Evolution does not diminish the absolute value of the perfect stage,
which is incomparably greater than the value of the intermediate stages,
it rather accentuates it. The stages from the half-developed acorn-shoot
are not equivalent in value to the perfect tree; they are to it as means
to an end, and are of minimal value compared with it.
4. All “descent” and “evolution,” which, even in regard to the gradual
development of physical organisation and its secrets, offer not so much an
explanation as a clue, are still less sufficient in regard to the origin
and growth of psychical capacity in general, and in relation to the
awakening and autonomy of the mind in man, because the psychical and
spiritual cannot be explained in terms of physiological processes, from
either the quantity or the quality of nervous structure.
This problem, and the relation of the human spirit to the animal mind,
will fall to be dealt with in Chapter XI. It is neither the right nor the
duty of the religious conception of the world to inquire into and choose
between the different forms of the idea of descent which we have met with.
If it has made itself master of the general evolution idea, then descent,
even in its most gradual, continuous, monophyletic form, affects it not at
all. It can then look on, perhaps not with joy, but certainly without
anxiety, at Dubois’ monkey-man and Friedenthal’s chimpanzee. On the other
hand, it is obvious that a secret bond of sympathy will always unite it
with the right wing of the theory of descent, with the champions of
“halmatogenesis,”(32) heterogenesis,(33) kaleidoscopic readjustment, &c.,
because in all these the depth and wealth and the mystery of phenomena are
more obviously recognisable. For the same reasons the religious outlook
must always be interested in all protests against over-hastiness, against
too great confidence in hypotheses, and against too rapid simplification
and formulation. And it is not going beyond our province to place some
reliance on the fact that there are increasing signs of revolt from the
too great confidence hitherto shown in relation to the Theory of Descent.
The general frame of the theory will certainly never be broken, but the
enclosed picture of natural evolution will be less plain and plausible,
more complex and subtle, more full of points of interrogation and
recognitions of the limits of our knowledge and the depths of things.