We can only know, in the scientific sense, the physical and chemical
phenomena of life; its essence, its origin, we can only know as
philosophy and idealism know them. We have to turn philosophers when we
ask any ultimate question. The feeling we have that the scientific
conception of life is inadequate springs from the philosophical habit of
mind. Yet this habit is quite as legitimate as the scientific habit, and
is bound to supplement the latter all through life.
The great men of science, like Darwin and Huxley, are philosophers in
their theories and conclusions, and men of science in their observations
and experiments. The limitations of science in dealing with such a
problem are seen in the fact that science can take no step till it has
life to begin with. When it has got the living body, it can analyze its
phenomena and reduce them to their chemical and physical equivalents,
and thus persuade itself that the secret of life may yet be hit upon in
the laboratory. Professor Czapek, of the University of Prague, in his
work on "The Chemical Phenomena of Life" speaks for science when he
says, "What we call life is nothing else but a complex of innumerable
chemical reactions in the living substance which we call protoplasm."
The "living substance" is assumed to begin with, and then we are told
that the secret of its living lies in its chemical and physical
processes. This is in one sense true. No doubt at all that if these
processes were arrested, life would speedily end, but do they alone
account for its origin? Is it not like accounting for a baby in terms of
its breathing and eating? It was a baby before it did either, and it
would seem as if life must in some way ante-date the physical and
chemical processes that attend it, or at least be bound up in them in a
way that no scientific analysis can reveal.
If life is merely a mode of motion in matter, it is fundamentally unlike
any and all other modes of motion, because, while we can institute all
the others at will, we are powerless to institute this. The mode of
motion we call heat is going on in varying degrees of velocity all about
us at all times and seasons, but the vital motion of matter is limited
to a comparatively narrow circle. We can end it, but we cannot start it.
The rigidly scientific type of mind sees no greater mystery in the
difference in contour of different animal bodies than a mere difference
in the density of the germ cells: "one density results in a sequence of
cell-densities to form a horse; another a dog; another a cat"; and avers
that if we "repeat the same complex conditions, the same results are as
inevitable as the sequences of forces that result in the formation of
hydrogen monoxide from hydrogen and oxygen."
Different degrees of density may throw light on the different behavior
of gases and fluids and solids, but can it throw any light on the
question of why a horse is a horse, and a dog a dog? or why one is an
herbivorous feeder, and the other a carnivorous?
The scientific explanation of life phenomena is analogous to reducing a
living body to its ashes and pointing to them--the lime, the iron, the
phosphorus, the hydrogen, the oxygen, the carbon, the nitrogen--as the
whole secret.
Professor Czapek is not entirely consistent. He says that it is his
conviction that there is something in physiology that transcends the
chemistry and the physics of inorganic nature. At the same time he
affirms, "It becomes more and more improbable that Life develops forces
which are unknown in inanimate Nature." But psychic forces are a product
of life, and they certainly are not found in inanimate nature. But
without laying stress upon this fact, may we not say that if no new
force is developed by, or is characteristic of, life, certainly new
effects, new processes, new compounds of matter are produced by life?
Matter undergoes some change that chemical analysis does not reveal. The
mystery of isomeric substances appears, a vast number of new compounds
of carbon appear, the face of the earth changes. The appearance of life
in inert matter is a change analogous to the appearance of the mind of
man in animate nature. The old elements and forces are turned to new and
higher uses. Man does not add to the list of forces or elements in the
earth, but he develops them, and turns them to new purposes; they now
obey and serve him, just as the old chemistry and physics obey and
serve life. Czapek tells us of the vast number of what are called
enzymes, or ferments, that appear in living bodies--"never found in
inorganic Nature and not to be gained by chemical synthesis." Orders and
suborders of enzymes, they play a part in respiration, in digestion, in
assimilation. Some act on the fats, some on the carbohydrates, some
produce inversion, others dissolution and precipitation. These enzymes
are at once the products and the agents of life. They must exert force,
chemical force, or, shall we say, they transform chemical force into
life force, or, to use Professor Moore's term, into "biotic energy"?