Machnical Theories Criticism
In attempting to define our attitude to the mechanical theory of life, we
have first of all to make sure that we have a right to take up a definite
position at all. We should have less right, or perhaps none, if this
theory of life were really of a purely "biological" nature, built up
entirely from the expert knowledge and data which the biologist alone
possesses. But the principles, assumptions, supplementary ideas and modes
of expression along all the six lines we have discussed, the style and
method according to which the hypothesis is constructed, the multitude of
separate presuppositions with which it works, and indeed everything that
helps to build up and knit the biological details into a scientific
hypothesis, are the materials of rational synthesis in general, and as
such are subject to general as well as to biological criticism. What is
there, for instance, in Weismann's ingenious biophor-theory that can be
called specifically biological, and not borrowed from other parts of the
scientific system?
One advantage, indeed, the biologist always has in this matter, apart from
his special knowledge; that is, the technical instinct, the power of
scenting out, so to speak, and immediately feeling the importance of the
facts pertaining to his own discipline. It is this that gives every
specialist the advantage over the layman in dealing with the data of his
own subject. This power of instinctively appraising facts, which develops
in the course of all special work, can, for instance in hypotheses in the
domain of history, transform small details, which to the layman seem
trivial, into weighty arguments. Similarly it may be that the success of
the mechanical interpretation in regard to isolated processes may make its
validity for many other allied processes certain, even though there is no
precise proof of this. But we cannot regard this as a final demonstration
of the applicability of the mechanical theory, since the same technical
instinct in other experts leads them to reject the whole hypothesis.
But here we are met with something surprising. May it not be that while we
are impelled on general grounds to contend against the mechanical
interpretation of vital phenomena, we are not so impelled on religious
grounds? May it not be that the instinct of the religious consciousness is
misleading when it impels us--as probably every one will be able to certify
from his own experience--to rebel against this mechanisation of life, the
mechanical solution of its mysteries? Lotze, the energetic antagonist of
"vital force," the founder of the mechanical theory of vital processes,
was himself a theist, and was so far from recognising any contradiction
between the mechanical point of view and the Christian belief in God, that
he included the former without ceremony in his theistic philosophical
speculations. His view has become that of many theologians, and is often
expressed in a definition of the boundaries between theology and natural
science. According to the idea which was formulated by Lotze, and
developed by others along his lines, the matter is quite simple. The
interest which religion has in the processes of nature is at once and
exclusively to be found in teleology. Are there purposes, plans, and ideas
which govern and give meaning to the whole? The interest of natural
science is purely in recognising inviolable causality; every phenomenon
must have its compelling and sufficient reason in the system of causes
preceding it. All that is and happens is absolutely determined by its
causes, and nothing, no causae finales for instance, can co-operate with
these causes in determining the result. But, as Lotze says, and as we have
repeatedly pointed out, causal explanation does not exclude a
consideration from the point of view of purpose, and the mechanical
interpretation does not do so either. For this is nothing more than the
causal explanation itself, only carried to complete consistency and
definiteness. Purposes and ideas are not efficient causes but results.
Where, for instance, there is a controlled purposive occurrence, the
"purpose" nowhere appears as a factor co-operating with the series of
causes, for these follow according to strict law, and the "purpose"
reveals itself at the close of the series, as the result of a closed
causal nexus, complete in itself, always provided that the initial links
in the chain have been accurately estimated. The same is true of the
processes of life. They are the ultimate result, strictly necessary and
sufficiently accounted for in terms of mechanical sequence, of a long
chain of causes whose initial links imply a definite constitution which
could not be further reduced. Whether this ultimate result is merely a
result or whether it is also a "purpose" is a question which, as we have
seen twice already, it is wholly beyond the power of the causal mode of
interpretation to answer. Given that an infinite intelligence in the world
wished to realise purposes without instituting them as directly
accomplished, but by letting them express themselves through a gradual
"becoming," the method would be exactly what is shown in the mechanical
theory of life, that is, the primitive data and starting-points would have
inherent in them a peculiar constitution and a rigidly inexorable
orderliness of causal sequence. And Lotze emphasises that it would also be
worthier of God to achieve the greatest by means of the simplest, and to
work out the realisation of His eternal purposes according to the strict
inevitableness of mechanism, than to attain His ends through the
complicated means, the adventitious aids, and all the irregularities
implied in the incommensurable activities of a "vital force." ("God needs
no minor gods.")
To Lotze himself these original data and starting points are the primitive
forms of life, which, according to his view, are directly "given," and
cannot be referred back to anything else (except to "creation"). But it is
obvious that his view can be enlarged and extended so as to refer the
derivation of the whole animate world to the original raw materials of the
cosmos (energy, matter, or whatsoever they may be), and to the orderly
process by which these materials were combined in various configurations
to form the chemical elements, the chemical compounds, living proteids,
the first cell, and the whole series of higher forms. If this nexus has
taken place, it is nothing else than the transformation of the "potential"
into the "actual" through strict causality. And if this actuality proves
itself to have claims, because of its own intrinsic worth, to be
considered as intelligent "purpose," the whole system of means, including
the starting-point, can be recognised as the means to an end, and the
original wisdom and the intelligence which ordained the purpose is only
glorified the more through the great simplicity, the rational
comprehensibility, and the inexorable necessity of the system, which
excludes all chance, and therewith all possibility of error.
This extension of Lotze's reconciliation of the mechanical causal with the
teleological point of view is impressive and, as far as it goes, also
quite convincing. It will never be given up, even if the point of view
should change somewhat. And we have already seen that it is quite
sufficient as long as we are dealing only with the question of teleology.
But we must ask whether religion will be satisfied with "teleology" alone,
or whether this is even the first requirement that it makes in regard to
natural phenomena. We have already asked the question and attempted to
clear the ground for an answer. Let us try to make it more definite.
Many people will have a certain uneasiness in regard to the Lotzian ideas;
they will be unable to rid themselves of a feeling that this way of
looking at things is only a pis aller for the religious point of view,
and that the fundamental requirements of religious feeling receive very
inadequate satisfaction on this method. The world of life which has arisen
thus is altogether too rational and transparent. It is calculable and
mathematical. It satisfies well enough the need for teleology, and with
that the need for a supreme, universally powerful and free intelligence;
but it gives neither support nor nourishment to the essential element in
religious feeling, through which alone faith becomes in the strict sense
religious. Religion, even Christian religion, is, so to speak, a
stratified structure, a graduated pyramid, expressing itself, at its
second (and undoubtedly higher) level, in our recognition of purpose, the
rationality of the world, our own spiritual and personal being and worth,
but implying at its basis an inward sense of the mysterious, a joy in that
which is incommensurable and unspeakable, which fills us with awe and
devotion. And religion at the second stage must not sweep away the essence
of the stage below, but must include it, at the same time informing it
with new significance. Whoever does not possess his religion in this way
will agree with, and will be quite satisfied with the Lotzian standpoint.
But to any one who has experience of the most characteristic element in
religion, it will be obvious that there must be a vague but deep-rooted
antipathy between religion and the mathematical-mechanical conception of
things. Evidence of the truth of this is to be found in the instinctive
perceptions and valuations which mark even the naive expressions of the
religious consciousness.(75) For it is in full sympathy with a world which
is riddled with what is inconceivable and incommensurable, in full
sympathy with every evidence of the existence of such an element in the
world of nature and mind, and therefore with every proof that the merely
mechanical theory has its limits, that it does not suffice, and that its
very insufficiency is a proof that the world is and remains in its depths
mysterious. Now we have already said that the true sphere for such feeling
is not the outer court of nature, but within the realm of the emotional
life and of history, and, on the other hand, that even if the attempt to
trace life back to the simpler forces of nature were successful, we should
still be confronted with the riddle of the sphinx. But any one who would
say frankly what he felt would at once be obliged to admit that the
religious sense is very strongly stirred by the mystery of vital
phenomena, and that in losing this he would lose a domain very dear to
him. These sympathies and antipathies are in themselves sufficient to give
an interest to the question of the insufficiency of the mechanical view of
things.
For it is by no means the case that the mechanical theory, with its
premisses and principles, is the interpretation that best fits the facts,
and that most naturally arises out of a calm consideration of the animate
world. It is an artificial scheme, and astonishing energy has been
expended on the attempt to fit it to the actual world, that it may make
this orderly and translucent. It certainly yields this service so far, but
not without often becoming a kind of strait-jacket, and revealing itself
as an artificiality. In so far as the special problems of biology are
concerned, we shall afterwards follow our previous method of taking our
orientation from those specialists in the subject who, in reaction from
the one-sidedness of the mechanical doctrine, have founded the
"neo-vitalism" of to-day. Here we are only concerned with the generalities
and presuppositions of the theory.
We must dispute even the main justification of the theory, which is sought
for in the old maxim of parsimony in the use of principles of explanation
(entia, and also principia, praeter necessitatem non esse
multiplicanda), and in Kant's "regulative principle," that science must
proceed as if everything could ultimately be explained in terms of
mechanism. For surely our task is to try to explain things, not at any
cost with the fewest possible principles, but rather with the aid of those
principles which appear most correct. If nature is not fundamentally
simple, then it is not scientific but unscientific to simplify it
theoretically. And the proposition bracketed above has its obvious
converse side, that while entities and principles must not be multiplied
except when it is necessary, on the other hand their number must not be
arbitrarily lessened. To proceed according to the fundamental maxims of
the mechanistic view can only be wholesome for a time and, so to speak,
for paedagogical reasons. To apply them seriously and permanently would be
highly injurious, for, by prejudging what is discoverable in nature, it
would tend to prevent the calm, objective study of things which asks for
nothing more than to see them as they are. It would thus destroy the
fineness of our appreciation of what there really is in nature. This is
true alike of forcible attempts to reduce the processes of life to
mechanical processes, and of the Darwinian doctrine of the universal
dominance of utility. Both bear unmistakably the stamp of foregone
conclusions, and betray a desire for the simplest, rather than for the
most correct principles of interpretation.
There is one point which presses itself on the notice even of outsiders,
and is probably realised even more keenly by specialists. The confidence
of the supporters of the mechanical theories of earlier days, from
Descartes onward, that animals and the bodies of men were machines,
mechanical automata, down to the mechanical theories of Lamettrie and
Holbach, of l'homme machine, and of the systeme de la nature, was at
least as great as, probably greater than, that of the supporters of the
modern theories. Yet how naive and presumptuous seem the crude and wooden
theories upon which the mechanical system was formerly built up, and how
falsely interpreted seem the physiological and other facts which lent them
support, when seen in the light of our modern physiological knowledge.
Vaucanson's or Drozsch's duck-automaton or clockwork-man, with which the
mechanical theorists of bygone days amused themselves, would not go far to
encourage the physiologist of to-day to pursue his mechanical studies, but
would rather throw a vivid light on the impossibility of comparing the
living "machine" with machines in the usual sense. For things emphatically
do not happen within the living organism in the same way as in the
automatic duck, and the more exact the resemblance to the functions of a
"real" duck became, the more did the system of means by which the end was
attained become unlike vital processes. It is difficult to resist the
impression that in another hundred years,--perhaps again from the
standpoint of new and definitely accepted mechanical explanations,--people
will regard our developmental mechanics, cellular mechanics, and other
vital mechanics much in the same way as we now look on Vaucanson's duck.
Associated or even identical with this is the fact that in proportion as
mechanical interpretation advances, the difficulties it has to surmount
continually crop up anew. Processes which seem of the simplest kind and
the most likely to be capable of purely mechanical explanation, processes
such as those of assimilation, digestion, respiration, for which it was
believed that exact parallels existed in the purely mechanical domain, as,
for instance, in the osmotic processes of porous membranes, are seen when
closely scrutinised as they occur in the living body to be extremely
complex; in fact they have to be transferred "provisionally" from the
mechanical to the vital rubric. To this category belong the whole modern
development of the cell-theory, which replaces the previously single
mechanism in the living body by millions of them, every one of which
raises as many problems as the one had done in the days of cruder
interpretation. Every individual cell, as it appears to our understanding
to-day, is at least as complicated a riddle as the whole organism formerly
appeared.
But further: the modern development of biology has emphasised a special
problem, which was first formulated by Leibnitz (though it is in
antithesis to his fundamental Monad-theory), and which appears incapable
of solution on mechanical lines. Leibnitz declared living beings to be
"machines," but machines of a peculiar kind. Even the most complicated
machine, in the ordinary sense, consists of a combination of smaller
"machines," that is to say, of wheels, systems of levers, &c., of a
simpler kind. And these sub-machines may in their turn consist of still
simpler ones, and so on. But ultimately a stage is reached when the
component parts are homogeneous, and cannot be analysed into simpler
machines. It is otherwise with the organism. According to Leibnitz it
consists of machines made up of other machines, and so on, into the
infinitely little. However far we can proceed in our analysis of the
parts, we shall still find that they are syntheses, made up of most
ingeniously complex component parts, and this as far as our powers of
seeing and distinguishing will carry us. That is to say: organisation is
continued on into the infinitely little.
Leibnitz's illustration of the fish-pond is well known. He could have no
better corroboration of his theory than the results of modern
investigation afford. His doctrine of the continuation of organisation
downwards into ever smaller expression is confirmed to a certain extent
even by anatomy. By analysing structural organisation down to cells a
definite point seemed to have been reached. But it now appears that at
that point the problem is only beginning. One organisation is made up of
other organisations--cells, protoplasm, nucleus, nucleolus, centrosomes,
and so on, according to the power of the microscope; and these structures,
instead of explaining the vital functions of growth, development,
multiplication by division, and the rest, simply repeat them on a smaller
scale, and are thus in their turn living units, the aggregation of which
is illustrated better by the analogy of a social organism than by that of
a mechanical structure.
In order to follow the mechanical explanation along the six lines we have
previously indicated, we shall, as we have already said, entrust ourselves
to the specialists who are on the opposite side. The difficulties and
objections which the mechanical theory has to face have forced themselves
insistently upon us even in the course of a short sketch such as has just
been given, but they will be clearly realised if we approach them from the
other side. But, first of all, a word as to the fundamental and, it is
alleged, unassailable doctrine on which the theory as a whole is based,
the "law of the conservation of energy." The appeal to this, at any rate
in the way in which it is usually made, is apt to be so distorted that the
case must first be clearly stated before we can get further with the
discussion.