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"Eternal process moving
on."
Tennyson
THE shorter the word the more inevitable it is that it will be used in many significations; as can be proved by looking out almost
any monosyllable in a large dictionary. The tendency of a simple word to have many glancing meanings-like shot silk, as Tennyson
put it - is a character of high literary value; though it may be occasionally inconvenient for scientific purposes. It is unlikely
that we can escape an ambiguity due to this tendency, but I wish to use the term 'life' to signify the vivifying principle which
animates matter.
That the behaviour of animated matter differs from what is
often called dead matter is familiar, and is illustrated by the description sometimes given of an uncanny piece of
mechanism - that "it behaves as if it were alive." In the case of a jumping bean,
for instance, its spasmodic and capricious behaviour can be explained with apparent simplicity, though with a suspicious trend
towards superstition, by the information that a live and active maggot inhabits a cavity inside. It is thereby removed from the
bare category of physics only, though still perfectly obedient to physical laws: it jumps in accordance with mechanics, but neither
the times nor the direction of its jumps can be predicted.(1)
(1) See
explanatory note A at end of chapter.
We must admit that the term 'dead matter' is often misapplied.
It is used sometimes to denote merely the constituents of the general inorganic world. But it is inconvenient to speak of utterly
inanimate things, like stones, as 'dead,' when no idea of life was ever associated with them, and when 'inorganic' is all that is
meant. The term 'dead' applied to a piece of matter signifies the absence of a vivifying principle, no doubt, but it is most
properly applied to a collocation of organic matter which has been animated.
Again, when animation has ceased, the thing we properly call
dead is not the complete organism, but that material portion which is left behind; we do not or should not intend to make any
assertion concerning the vivifying principle which has left it,- beyond the bare fact of its departure. We know too little about
that principle to be able to make safe general assertions. The life that is transmitted by an acorn or other seed fruit is always
beyond our ken. We can but study its effects, and note its presence or its absence by results.
Life must be considered sui generis; it is not a form of energy,
nor can it be expressed in terms of something else. Electricity is in the same predicament; it too cannot be explained in terms of
something else. This is true of all fundamental forms of being. Magnetism may be called a concomitant of moving electricity;
ordinary matter can perhaps be resolved into electric charges: but an electric charge can certainly not be expressed in terms of either
matter or energy. No more can life. To show that the living principle in a seed is not one of the forms of energy, it is sufficient
to remember that that seed can give rise to innumerable descendants, through countless generations, without limit. There
is nothing like a constant quantity of something to be shared, as there is in all examples of energy: there is no conservation about it:
the seed embodies a stimulating and organising principle which appears to well from a limitless source.
But although life is not energy, any more than it is matter, yet it directs energy and thereby controls arrangements of matter.
Through the agency of life specific structures are composed which would not otherwise exist, from a sea-shell to a cathedral,
from a blade of grass to an oak; and specific distributions of energy are caused, from the luminosity of a firefly to an electric
arc, from the song of a cricket to an oratorio.
Life makes use of any automatic activities, or transferences
and declensions of energy, which are either potentially or actually occurring. In especial it makes use of the torrent of ether tremors
which reach the earth from the sun. Every plant is doing it constantly. Admittedly life
exerts no force, it does no work, but it makes effective the energy available for an organism which it controls and vivifies; it
determines in what direction and when work shall be done. It is plain matter of fact that it does this, whether we understand the
method or not,- and thus indirectly life interacts with and influences the material world. The energy of coal is indirectly
wholly solar, but without human interference it might remain buried in the earth, and certainly would never propel a ship across the
Atlantic. One way of putting the matter is to say that life times, and directs. If it runs a railway train, it runs the train not like a
locomotive but like a General Manager. It enters into battle with a walking-stick, but guns are fired to its orders. It may be said to aim
and fire: one of its functions is to discriminate between the wholesome and the deleterious, between friend and foe. That is a
function outside the scope of physics.
Energy controlled by life is not random energy: the kind of self-composition or personal structure built by it depends on the kind
of life-unit which is operating, not on the pabulum which is supplied. The same food will serve to
build a pig, a chicken, or a man. Food which is assimilable at all takes a shape determined by
the nature of the operative organism, and indeed by the portion of the organism actually reached by it. Unconscious constructive
ability is as active in each cell of the body as in a honeycomb; only in a beehive we can see the operators at work. The
construction of an eye or an ear is still more astonishing. In the inorganic world such structures would be meaningless, for there
would be nothing to respond to their stimulus; they can only serve elementary mind and consciousness. The brain and nerve
system is an instrument of transmutation or translation from the physical to the mental, and vice versa.
Stages
of Evolution
Steps in the progress of evolution-great stages which have
been likened by Sir James Crichton Browne to exceptional Mendelian Mutations-may be rather imaginatively
rehearsed somewhat thus:
Starting with
-
The uniform Ether of Space, we can first suppose
-
The specialisation or organisation of specks of ether into
Electrons; followed by
-
Associated systems of electrons, constituting atoms of
Matter; and so
-
The whole inorganic Universe.
Then, as a new and astonishing departure,
comes-
-
The cell, or protoplasmic complex which Life can
construct and utilise for manifestation and development."
-
And after that
A brain cell, which can become the physical organ for the rudiments of Mind. Followed by
-
Further mental development until Consciousness becomes
possible. With subsequent
-
Sublimation of consciousness into Ethics, Philosophy,
and Religion.
We need not insist on these or any other stages for our
present purpose; yet something of the kind would seem to have occurred, in the mysterious course of time.(1)
(1) See
explanatory note B.
Three
Explanatory Notes
Note
A - Mechanics of Jumping Bean
The biological explanation of a jumping bean is sometimes felt to be
puzzling, inasmuch as the creature is wholly enclosed; and a man in a boat knows that he cannot propel it by movement inside, without touching the
water or something external. But the reaction of a table can be made use of through the envelope, and a live thing can momentarily vary its own
weight - pressure and even reverse its sign. This fact has a bearing on some psycho-physical
experiments, and hence is worthy of a moment's attention.
To weigh an animal that jumps and will not keep still is always
troublesome. It cannot alter its average weight, truly, but it can redistribute it in time; at moments its apparent weight may be excessive, and at other
moments zero or even negative, as during the middle of an energetic leap. Parenthetically we may here interpolate a remark and say that what is called
interference of light (two lights producing darkness, in popular language) is a redistribution of luminous energy in space. No light, nor any kind of wave
motion, is destroyed by interference when two sets of waves overlap, but the energy rises to a
maximum in some places, and in other places sinks to zero.
No wave energy is consumed by interference-only rearranged. This fact is
often misstated. And probably the other statement, about the varying apparent
weight - ie. pressure on the ground-of a live animal, may be misstated too: though there is no question of energy about that, but only of
force. The force or true weight, in the sense of the earth's attraction, is there
all the time, and is constant; but the pressure on the ground, or the force needed to counteract the weight, is not constant. After momentary
violence, as in throwing, no support need be supplied for several seconds; and, like the maggot inside a hollow bean, a live thing turning itself into a
projectile may even carry something else up too. It is instructive also to consider a flying bird, and a dirigible balloon, and to ask where the still
existing weight of these things can be found.
Note
B - Differences Between a Goring Organism and a Growing Crystal
The properties which differentiate living matter from any kind of
inorganic imitation may be instinctively felt, but can hardly be formulated without expert knowledge. The differences between a growing organism and
a growing crystal are many and various, but it must suffice here to specify the simplest and most familiar sort of difference; and as it is convenient to
take a possibly controversial statement of this kind from the writings of a physiologist, I quote here a passage from an article by Professor Fraser
Harris, of Halifax, Nova Scotia, in the current number of the quarterly magazine called Science Progress edited by Sir Ronald Ross
"Living animal bioplasm has the power of growing, that is of
assimilating matter in most cases chemically quite unlike that of its own constitution. Now this is a remarkable power, not in the least degree shared
by non-living matter. Its very familiarity has blinded us to its uniqueness as a
chemical phenomenon. The mere fact that a man eating beef, bird, fish, lobster, sugar, fat, and innumerable other things can transform these into
human bioplasm, something chemically very different even from that of them which most
resembles human tissue, is one of the most extraordinary facts in animal physiology. A crystal growing in a solution is not only not
analogous to this process, it is in the sharpest possible contrast with it. The
crystal grows only in the sense that it increases in bulk by accretions to its
exterior, and only does that by being immersed in a solution of the same material as its own substance. It takes up to itself only material which is
already similar to itself; this is not assimilation, it is merely incorporation.
"The term 'growth', strictly speaking, can. be applied. only to
metabolism in the immature or convalescent organism. The healthy adult is not 'growing' in this sense; when of constant weight he is adding neither to
his stature nor his girth, and yet he is assimilating as truly as ever he did. Put
more technically: in the adult of stationary weight, anabolism is quantitatively equal to katabolism, whereas in the truly growing organism
anabolism is prevailing over katabolism; and reversely in the wasting of an organism or in senile decay, katabolism is prevailing over anabolism. The
crystal in its solution offers no analogies with the adult or the senile states-
but these are of the very essence of the life of an organism. . . .
"The fact, of course familiar to every beginner in biology, is that the
crystal is only incorporating and not excreting anything, whereas the living matter is always excreting as well as assimilating. This one-sided
metabolism - if it can be dignified with that term--is indeed characteristic of the crystal,
but it is at no time characteristic of the living organism. The organism, whether truly growing or only in metabolic equilibrium, is constantly taking
up material to replace effete material, is replenishing because it has previously displenished itself or cast off material. The resemblance between
a so-called 'growing' crystal and a growing organism is verily of the most superficial kind."
And Professor Fraser Harris concludes his article thus:
"Between the living and the non-living there is a great gulf fixed, and
no efforts of ours, however heroic, have as yet bridged it over."
Note
C - Cold Age
We know that as vitality diminishes the bodily deterioration called old
age sets in, and that a certain amount of deterioration results in death; but it turns out, on systematic inquiry, that old age and
death are not essential to living organisms. They represent the deterioration and wearing out of working parts, so that the vivifying principle is hampered
in its manifestation and cannot achieve results which with a younger and healthier machine were possible; but the parts which wear out are not the
essential bearers of the vivifying principle; they are accreted or supplementary portions appropriate to developed individual earth life, and it
does not appear improbable that the progress of discovery may at least postpone the deterioration that we call old age, for a much longer time than
at present. Emphasis on this distinction between germ cell and body cell, usually associated with Weismann, seems to have been formulated before
him by Herdman of Liverpool.
Biologists teach us that the phenomenon of old age is not evident in
the case of the unicellular organisms which reproduce by fission. The cell can be killed, but it need neither grow old nor die. Death appears to be a
prerogative of the higher organisms. But even among these Professor Weismann adopts and defends the view that "death is not a primary
necessity, but that it has been secondarily acquired by adaptation." The cell is not inherently limited in its number of cell-generations. The low
unicellular organism is potentially immortal; the higher multicellular form, with well-differentiated organs, contains the germ of death within its soma.
Death seems to supervene by reason of its utility to the species: continued life of an individual after a certain stage being comparatively useless. From
the point of view of the race the soma or main body is "a secondary appendage of the real bearer of life-the reproductive cells." The somatic
cells probably lost their immortal qualities on this immortality becoming useless to the species. Their mortality may have
been a mere consequence of their differentiation. "Natural death was not introduced from absolute
intrinsic necessity, inherent in the nature of living matter," says Weismann, "but on grounds of utility; that is from necessities which sprang up, not from
the general conditions of life, but from those special conditions which dominate the life of multicellular
organisms.
It is not the germ cell itself, but the bodily accretion or appendage,
which is abandoned by life, and which accordingly dies and decays.
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