CHAPTER VII
THEORIES OF LIFE

We find that the theories of the nature of life divide
themselves into two varieties: the mechanistic and the
vitalistic. The former kind of theory states that all
living phenomena are to be explained solely by the
ordinary physical laws, and that life differs from other
phenomena only on account of its complexity, or in some
other incidental manner. On the other hand, the vital-
istic theories are to the effect that living phenomena are
characterized by some mysterious sort of "vital force"
which would seem to have the power to suspend or alter
the operation of the physical laws that govern the rest
of the universe. In the course of the history of science,
much has been said both for the vitalistic and the
mechanistic theories, and, as yet, no agreement has
actually been reached on that subject.
In the attempt to solve our paradox of the second law
of thermodynamics, we have incidentally reached a
suggestion of the nature of life. According to the
conclusions we have reached, there are in the universe
what we have called positive tendencies, neutral tendencies,
and negative tendencies, all of which are possible results
of the reversible physical laws governing the motion of
particles of matter. The neutral tendency being an
extremely improbable result, very few cases of it are
likely to take place; but, in any given case, unless further
special circumstances alter the probabilities, the posi-
tive or the negative tendency has a 50% probability,
and will therefore result from the reversible laws in
about half of the cases occurring in the universe. In
our section of the universe the positive tendency, how-
ever, preponderates, though, inasmuch as it would be
extremely improbable that any section of the universe
is entirely without instances of the negative tendency,
it follows that there must be phenomena of the negative
tendency within our observation. The phenomena of
the negative tendency are the living phenomena; while
the phenomena of the positive tendency sre the non-
living phenomena.
This theory of life is strictly mechanisitic in so far
as life is assumed to operate solely under the physical
laws applying to the motion of particles, which laws
are sufficient to determine a complete chain of causa-
tion. On the contrary, physicists, confining their ob-
servation entirely to inanimate matter, have reached the
conclusion that there is further physical law, the
so-called second law of thermodynamics, which is sus-
pended by living phenomena. There is according to our
theory, this essential difference between living and non-
living phenomena; and this difference would supply the
basis for the idea of "vital force." Thus the two theories
of life can be reconciled.
On the matter of the difference between living and
non-living bodies, there is still less agreement. For in-
stance, it is stated that lifeless substances, in so far as
they form definite shapes, form only geometrical shapes,
while living substances form irregular shapes. Out-
side of the fact that this does not distinguish living
bodies from bodies which were once alive but which
have lost the property of life, and outside of the fact
that not all inorganic substances but only certain solid
substances form geometrically shaped crystals, we may
refute the statement that living bodies always have
irregular shapes by simply adducing the example of
the egg. This distinction is therefore on all sides un-
tenable.
Again, it has been said that the difference between
living and lifeless substances is the question of the
presence of organs. But will that alone distinguish the
average organism from a machine? The same objec-
tion can be urged against the proposed distinction on
the ground that living bodies have a complex organiza-
tion. However, either of these proposed distinctions
may mean that a living body is so organized that every-
thing has its teleological function; and this leads us
to a proposed distinction between living and non-living
bodies, namely, that living phenomena are essentially
teleological. In the can of a machine we have the or-
ganiztion, but the teology must be sought for in
the living being that assembled the machine. Appar-
ently, teology is a characteristic of life; but yet every-
thing is explicable on a physico-chemical basis; there-
fore we have in life the property of apparent teleology
as a distingushing characteristic. Only in this form
can the proposed diiferentiation on the basis of "or-
ganiztion" be tenable. But, as we have seen, apparent
teleology is one of the characteristics by which a re-
versal of the second law of thermodynamics can be
recognized. It therefore follows that, in all probability,
our distinction on the basis of the second law of ther-
modynamics is really the fundamental of dif-
ference between living and non-living bodies.
Another suggested method of differentiation is in the
capability of reproduction. But, when we come down to
the ultimate living units, the cells, this reproduction
consists merely of contriction and division; in which
it is hardly to be differentiated from the breaking up
into smaller drops of a drop of oil in water or a drop
of mercury on a glass surface under slight shock.
As we have seen, while under ordinary circumstances a
shock is necessary to accomplish this division in these
cases, yet, under the reversal of the second law of
thermodynamics, this form of division is a normal
phenomenon.
A further suggestion as to a method of differentia-
tion is that life always derived from other life, while
inanimate matter may be derived from either living
or non-living bodies. This distinction is a general one,
simply stating a fact, but cannot server as a definition or
as a means of differentiation, because it would not show
whether any individual case was one of living or life-
less substance. Should we try to apply the test, we
should have to ask whether it could only have been de-
rived from other living matter. What it could have
been derived from we cannot experimentally find out;
the actual causes might be discovered, and then we are
reduced to the question whether life is to be found
amoung those causes, and we are now no better off than
at first. It is like trying in an unknown region to find
the east by the directions in Schedrin's story: Face the
north, and the east is on your right. Such directions
obviously are useless where the north is as unknown
as the east. The basis of fact behind this proposed
distinction between living and lifeless bodies, however,
we will examine more in detail later on.
The suggestion that organic bodies grow by absorb-
ing particles, while growth, where it is found among in-
organic bodies, is always by accertion of matter on the
outside, turns out, when analysed, to be rather a dis-
tinction between solids and liquids than one between liv-
ing and lifeless substance. The absorption of particles
can be duplicated in the laboratory under circumstances
by liquids enclosed in membranes, and a living cell
consists of a membrane containing liquids.
Finally, we come to the dynamical distinctions. The
most obvious of these is, to say that life is distinguished
by movement. This is obvioulsy an incorrect distinction,
since all objects are in motion. But there is obviously
something peculiar about living movement that seems
to make it seem more mobile than other movement. It
is thus, for instance, alleged, that living movement comes
from internal causes, or else that living bodies work of
themselves, while other objects need to be supplied with
energy. Ecen that is not descriptive, for there are al-
ways "external" causes for all movements, and life does
not create energy; if it uses up energy, it must obtain
that energy from somewhere. Similarly with the dis-
tinction between static equilibrium of life, often more
accuratley defined as the metabolic process; such a dyn-
amic equilibrium exists (as molar energy) in the case of
almost all machines, and chemically in the case of any
catalytic agent, which is also being constantly decom-
posed and recomposed.
But there are more accurate definitions of this
mobility which is so peculiarly characteristic of life. We
may notice, for instance, the theory advanced by the late
Prof. William James, the theory of the existence of a
"reserve energy" in the case of biological, and especially
in the psychological, activities, which is absent in the case
of lifeless activities. According to this, while the living
organism can normally use a certain amount of its en-
ergy; yet in some mysterious way it can, under special
circumstances, draw on an immense surplus fund of
"reserve energy." This property being absent in phy-
sical bodies, we may draw a distinction on that basis
between living and lifeless bodies, and this would seem
to be an absolute distinction. Now, it has long been
known that physical bodies contain an immense amount
of energy which is unavailable for conversion into any-
thing else; and the physical law that limits the amount
of energy which it is possible for a physical body to
utilize is precisely this second law of thermodynamics
taht has given us so much trouble. We must therefore
come to the conclusion that, since life does not create
energy, and this "reserve energy" is evidently real
physical energy, that the peculiarity of life is its ability to
draw on more energy than the second law of thermodyn-
amics would allow; that is, its ability, in some circumstances
at least, to reserve that second law. And again, we have
seen that reversals of the second law are characterized
by ability to use a fund of reserve energy that physical
bodies cannot use. Let us say that the mechanical
efficency of a set of bodies is 85%; the reciprocal, or
118%, is that of the same set in the reverse universe.
But as, under some circumstances, producing special
results in the way of heat, etc., not quite 85% of the
energy will be used, but, let us say, only 50%, then
under those special cases in the reverse universe re-
quiring more energy, the mechanical efficiency will be
not 188%, but 200%, thus using over five times the
amount of reserve energy normally used. This
excess constitutes James's "reserve energy."
Another definition of the mobility of life is what is
called "irritability," that is to say, the ability to make
a large response to small stimuli. This, it is alleged,
is possessed only by life, so that life may be defined by
irritability. Against this Verworn objects that such
inanimate substances as nitroglycerine also possess this
property, that substance producing a powerful explosin
under the influence of a slight shock. But in the case
of nitroglycerine, we have an unstable equilibrium, and
a slight shock simply lets loose the difference of level
necessary to reduce to a stable equilibrium; while in the
case of life, irritability is part of the so-called "dynamic
equilibrium" and does not disturb that equilibrium. Irri-
tability, as it is found in biological phenomena, is the
ability to produce normally a large effect from a small
stimulus without an irreparable leveling down of
energy; in other words, the irritability that distinguishes
life consists of the ability to build up higher differences
of energy-level from lower ones, in exactly the inverse
order to that required by the second law of thermody-
namics. In other words, irritability is identical with the
"negative tendency" or, in other words, with the reversal of
the second law of thermodynamics. Thus we are again
reduced to our form of distinction between living and
non-living bodies, namely, that between the negative
and the positive tendency.
Verworn proposed the distinction on the basis of
chemical constituency namely, that living bodies con-
sist of complicated carbon compounds, such as albumen,
protein, etc., which cannot be produced outside of life.
But in what way would this definition distinguish a
living body from, let us say, a corpse? Or, according
to the definiton by chemical composition, every wooden
object is alive. It is obvious, therefore, that this dis-
tinction is untenable.
On the contrary, we have the extreme mechanisitic
view, represented by Dr. Jacques Loeb, that such a
distinction cannot be drawn. The actual existence of a
hard and fast distinction of this sort is, indeed difficult
to prove, but there is certainly a difference in appear-
ance, which must be based on something, however flimsy
that something might be. Dr. Loeb calls a living body
"a chemical machine," and states as the only base of
differentiation " the power of automatic development,
self-preservation, and reproduction." It is not quite
clear whether or not all three properties are essential;
and not all living bodies possess at all time all these
three properties; while, on the contrary, these properties
separately are possessed under certain circumstances by
certain non-living bodies; so that, to say the least, this
attempted distinction must be cleared up somewhat
before it can be of any service at all.
Thus, of all the distinguishing characteristics that may
be used to define life, we have left simply these three:
apparent teleology, reserve energy, and irritability. The
latter property (irritability) is, as we have seen, a con-
densed statement of the reverse of the second law of
thermodynamics; while we have seen before that the
other two properties, apparent teleology and reserve
energy, are the outstanding characteristics by which
a reversal of the second law of thermodynamics can
be recognized. It follows, therefore, that the funda-
mental definition behind all these is: Life is a reversal of
the second law of thermodynamics. Or, to put it in
other terms, since we have seen that mechanical effi-
ciency under positive tendency is less than 100%,
under neutral tendency just 100%, and under the
negative tendency more than 100%, we may define:
Life consists of bodies with a mechanical efficiency of
over 100%.