EVOLUTION UNIVERSAL
_The Starting-point--Inorganic Evolution--What Spencer tried to
do--Summary of his Evolutionism--Notes and Queries--The Origin of
Life--Evolution of Mind--Ascent of Man--The Scientific Position_
Every attempt to describe how our world has come to be as it is must
begin somewhere. It must postulate an initial state of Being from which
to start any particular chapter in the story of Becoming. How the
simplest conceivable raw material began--if it ever began--the
evolutionist cannot tell.
_The Starting-point._--Spencer began as far back as his scientific
imagination could take him--with "formless diffused matter." With this
to start with, he utilised the "Nebular Hypothesis" of Laplace, which
showed how the planetary system may have arisen by the diffused matter
becoming aggregated through the force of attraction into different
centres. This theory has been corroborated and improved by subsequent
researches in thermodynamics and spectroscopy, and in a modified form it
is very generally accepted. The researches of Sir Norman Lockyer on
"Inorganic Evolution" (1900) and of M. Faye (Sur l'origine du monde,
2nd. ed., Paris 1885) have strengthened and broadened the foundation of
Spencer's Evolutionism; many inquiries point to the idea that matter has
a homogeneous constitution; and the recent revolutionary discoveries
centred in "radio-activity" have given new life to the view that the
eighty odd elements of the chemist have had a long history behind them,
and have evolved from simple homogeneous units. The alchemists' dream
seems to be coming true, for we hear whispers of the transmutation of
elements. "It may be true," as Prof. R. K. Duncan says in his _New
Knowledge_ (1905) "that all bodily existence is but the manifestation of
units of negative electricity lying embosomed in an omnipresent ether of
which these units are, probably, a conditioned part."
_Inorganic Evolution._--We cannot follow this fascinating new story of
inorganic evolution, but we wish to point out that the progress of
science since Spencer wrote his _First Principles_ has tended to justify
him in beginning with formless diffused homogeneous matter. Were that
work being written to-day, it would have to be entirely recast. It would
probably begin (as Prof. Duncan sketches) with units of negative
electricity, assuming motion and carrying with them bound portions of
the ether in which they are bathed, becoming corpuscles endowed with the
primary qualities of matter superimposed upon those of electricity.
"Corpuscles congregating into groups or various configurations
constitute essentially the atoms of the chemical elements, locking up in
these configurations super-terrific energies, and leaving but "a slight
residual effect" as chemical affinity or gravitation with which we
attempt to carry on the work of the world. These atoms, congregating in
their turn as nebulae and under the slight residual force of gravitation
condense into blazing suns. The suns decay in their temperature and
become ever more and more complex in their constitution as the atoms
lock themselves into multiple forms. We then see these multiple atoms
developing up into the molecules of matter to form a world. We see the
molecules growing ever more and more complex as the world grows colder
until we attain to organic compounds. We see these organic compounds
united to form living beings and we see these living beings developing
into countless forms, and, after aeons of time, evolving into a dominant
race which is Us" (_The New Knowledge_, pp. 252-3). Of course there is
both imagination and faith in Prof. Duncan's "We see," but no one at all
aware of recent advances will doubt that the scientific cosmogony is
evolving rapidly, and that its movement is towards a fuller revelation
of the Unity of Nature.
_What Spencer tried to do._--Spencer's aim was to show that "our
harmonious Universe once existed potentially as formless diffused
matter, and has slowly grown into its present organised state." He
sought to account for its growing "in terms of Matter, Motion, and
Force." Of course he was careful to explain that "the interpretation of
all phenomena in terms of Matter, Motion, and Force, is nothing more
than the reduction of our complex symbols of thought, to the simplest
symbols; and when the equation has been brought to its lowest terms the
symbols remain symbols still." His common denominator for all phenomena
was "Matter, Motion, and Force," but he also recognised a greatest
common measure--"the unknown Cause co-extensive with all orders of
phenomena," "the unknown Reality which underlies all things," "a Power
of which the nature remains for ever inconceivable," and of which
phenomena are merely the manifestations. But while he was technically an
abstract Monist, he was practically a "mechanist," believing that it was
feasible to redescribe all evolution in terms of mechanical categories.
The scientific ideal to which he looked forward is expressed in the
sentence: "Given the Persistence of Force, and given the various
derivative laws of Force, and there has to be shown not only how the
actual existences of the inorganic world necessarily exhibit the traits
they do, but how there necessarily result the more numerous and involved
traits exhibited by organic and super-organic existences--how an
organism is evolved, what is the genesis of human intelligence, whence
social progress arises?" (_First Principles_, p. 555). He looked forward
to a unification of knowledge, to "_one science_, which has for its
object-matter the continuous transformation which the universe
undergoes." "Evolution being a universal process, one and continuous
throughout all forms of existence, there can be no break, no change from
one group of concrete phenomena to another without a bridge of
intermediate phenomena."
_Summary of Spencer's Evolutionism._--Spencer drew up the following
summary for publication in Appleton's _American Cyclopaedia_.[10]
1. Throughout the universe, in general, and in detail, there is an
unceasing redistribution of matter and motion.
2. This redistribution constitutes evolution where there is a
predominant integration of matter and dissipation of motion, and
constitutes dissolution where there is a predominant absorption of
motion and disintegration of matter.
3. Evolution is simple when the process of integration, or the
formation of a coherent aggregate, proceeds uncomplicated by other
processes.
4. Evolution is compound when, along with this primary change from
an incoherent to a coherent state, there go on secondary changes,
due to differences in the circumstances of the different parts of
the aggregate.
5. These secondary changes constitute a transformation of the
homogeneous into the heterogeneous--a transformation which, like
the first, is exhibited in the universe as a whole and in all (or
nearly all) its details--in the aggregate of stars and nebulae; in
the planetary system; in the earth as an inorganic mass; in each
organism, vegetal or animal (von Baer's law); in the aggregate of
organisms throughout geologic time; in the mind; in society; in all
products of social activity.
6. The process of integration, acting locally as well as generally,
combines with the process of differentiation to render this change,
not simply from homogeneity to heterogeneity, but from an
indefinite homogeneity to a definite heterogeneity; and this trait
of increasing definiteness, which accompanies the trait of
increasing heterogeneity, is, like it, exhibited in the totality of
things, and in all its divisions and sub-divisions down to the
minutest.
7. Along with this redistribution of the matter composing any
evolving aggregate there goes on a redistribution of the retained
motion of its components in relation to one another; this also
becomes, step by step, more definitely heterogeneous.
8. In the absence of a homogeneity that is infinite and absolute,
this redistribution, of which evolution is one phase, is
inevitable. The causes which necessitate it are:--
9. The instability of the homogeneous, which is consequent upon the
different exposures of the different parts of any limited aggregate
to incident forces. The transformations hence resulting are
complicated by--
10. The multiplication of effects: every mass and part of a mass on
which a force falls sub-divides and differentiates that force,
which thereupon proceeds to work a variety of changes; and each of
these becomes the parent of similarly multiplying changes: the
multiplication of these becoming greater in proportion as the
aggregate becomes more heterogeneous. And these two causes of
increasing differentiations are furthered by--
11. Segregation, which is a process tending ever to separate unlike
units, and to bring together like units, so serving continually to
sharpen or make definite differentiations otherwise caused.
12. Equilibration is the final result of these transformations
which an evolving aggregate undergoes. The changes go on until
there is reached an equilibrium between the forces which all parts
of the aggregate are exposed to, and the forces these parts oppose
to them. Equilibration may pass through a transition stage of
balanced motions (as in a planetary system), or of balanced
functions (as in a living body), on the way to ultimate
equilibrium; but the state of rest in inorganic bodies, or death in
organic bodies, is the necessary limit of the changes constituting
evolution.
13. Dissolution is the counterchange which sooner or later every
evolved aggregate undergoes. Remaining exposed to surrounding
forces that are unequilibrated, each aggregate is ever liable to be
dissipated by the increase, gradual or sudden, of its contained
motion; and its dissipation, quickly undergone by bodies lately
animate, and slowly undergone by inanimate masses, remains to be
undergone at an indefinitely remote period by each planetary and
stellar mass, which, since an indefinitely remote period in the
past, has been slowly evolving: the cycle of its transformations
being thus completed.
14. This rhythm of evolution and dissolution, completing itself
during short periods in small aggregates, and in the vast
aggregates distributed through space completing itself in periods
which are immeasurable by human thought, is, so far as we can see,
universal and eternal: each alternating phase of the process
predominating--now in this region of space, and now in that--as
local conditions determine.
15. All these phenomena, from their great features down to their
minutest details, are necessary results of the persistence of force
under its forms of matter and motion. Given these in their known
distributions through space, and their quantities being
unchangeable, either by increase or decrease, there inevitably
result the continuous redistributions distinguishable as evolution
and dissolution, as well as all those special traits above
enumerated.
16. That which persists, unchanging in quantity, but ever-changing
in form, under these sensible appearances which the universe
presents to us, transcends human knowledge and conception; is an
unknown and an unknowable power, which we are obliged to recognise
as without limit in space, and without beginning or end in time.
And the universal formula of Evolution stands thus: "Evolution is an
integration of matter and concomitant dissipation of motion; during
which the matter passes from an indefinite, incoherent homogeneity to a
definite, coherent heterogeneity; and during which the retained motion
undergoes a parallel transformation" (_First Principles_, p. 396).
_Notes and Queries._--(1) It should be noted that Spencer never
suggested that he had explained the origin of things. On the contrary,
"While the genesis of the Solar System, and of countless other systems
like it, is thus rendered comprehensible, the ultimate mystery remains
as great as ever. The problem of existence is not solved: it is simply
moved further back." What he offered was a genetic description, and that
is all that the scientific evolutionist ever offers.
(2) In the strict sense Spencer was no materialist. "Though the relation
of subject and object renders necessary to us these antithetical
conceptions of Spirit and Matter, the one is no less than the other to
be regarded as but a sign of the Unknown Reality which underlies both."
"Matter, Motion, and Force are but symbols of the Unknown Reality."
"Only in a doctrine which recognises the Unknown Cause as co-extensive
with all orders of phenomena, can there be a consistent Religion, or a
consistent Philosophy." "Were we compelled to choose between the
alternatives of translating mental phenomena into physical phenomena, or
of translating physical phenomena into mental phenomena, the latter
alternative would seem the more acceptable of the two."
It is one of the difficulties of Spencer's system that even when he is
using physical concepts he is thinking of these not merely as symbols by
which to formulate the routine of our sense-experience, but as symbols
of the reality behind matter and motion of which we do not know
anything. He works with the concept which he calls "the persistence of
force," and when the reader is feeling its inadequacy to meet the
situation, he is bluffed by the reminder--"By persistence of force we
really mean the persistence of some Power which transcends our knowledge
and conception": "Asserting the persistence of Force is but another mode
of asserting an Unconditioned Reality without beginning or end."
(3) When an investigator in giving an account of a process insists on
using higher categories than the sequences appear to require, he is
guilty of "_a transcendentalism_," e.g., if he says that an instinctive
action is rational, or that digestion is a psychical process. Similarly,
when an investigator in giving an account of a process insists on using
lower categories than the sequences appear to require, he is guilty of
"_a materialism_," _e.g._, if he says that a rational act is simply a
higher reflex, or that digestion is simply a chemical reaction.
Therefore, although Spencer was not a materialist, we think that he was
guilty of gross "materialisms," of attempting to give a false simplicity
to the facts, _e.g._, in his attempt to trace the evolution of mind in
terms of the evolution of the nervous system, and in his universal
evolution-formula which is wholly in terms of Matter and Motion.
(4) By keeping throughout to mechanical categories, Spencer gives a
semblance of simplicity and precision to his evolutionism, and his skill
is such that the unwary reader is led gently on from orders of facts
where mechanical categories (if not Spencer's) do certainly suffice, to
other orders of facts--in immaterial evolution--where they seem
strangely irrelevant. But if the reader, having his suspicions aroused
by sundry jolts and jars in the onward sweep of the chariot of First
Principles, begins to inquire into the reality of the apparent
mechanical precision, he is likely to be disillusioned. Thus, at an
early stage, he may discover that Spencer uses the word "force" without
special definition in at least five senses,[11] which is not reassuring.
As we have no expertness in these matters, we would submit the verdict
of a recognised authority, Prof. Karl Pearson. One of Spencer's
principles is "the redistribution of force," which he states in the
following words:--
"A decreasing quantity of motion, sensible or insensible, always
has for its concomitant an increasing aggregation of matter, and
conversely an increasing quantity of motion, sensible or
insensible, has for its concomitant a decreasing aggregation of
matter."
In regard to this Prof. Pearson remarks: "This principle has, so far as
I am aware, no real foundation in physics... it seems, so far as I can
grasp it at all, to flatly contradict the modern principle of the
conservation of energy"... the keystone of Spencer's system.
(5) What has taken place since Spencer stereotyped his _First
Principles_ seems to us to have rendered it almost useless to attempt a
detailed criticism of his scheme of evolution--wonderful and stimulating
as it was and is. He spoke of his delight in "intellectual hunting," and
a great huntsman he certainly was, but the _venue_ has changed since his
day. He did not fully nor always rightly utilise the chemistry and
physics of his time, and we have now to deal with a new chemistry and a
new physics.
Mr J. B. Crozier speaks of Spencer as "of all thinkers ancient or modern
the one whose power of analysing, decomposing, and combining the complex
web of Matter, Motion, and Force is the most incontestable and assured."
He describes Spencer's system as "No mere logical castle built of air
and definitions, and assuming in its premises, like the systems of the
metaphysicians, the very difficulties to be explained, but a great
granite pile sunk deep in the bed-rock of the world, each stone a
scientific truth, and all so compacted and dove-tailed together that it
was difficult to find anywhere a logical flaw among their seams."
This is one view, but another will be found in Prof. James Ward's
Gifford Lectures on "Naturalism and Agnosticism," in Mr Malcolm
Guthrie's three volumes of criticism, and in several luminous papers by
Principal James Iverach.
When we think of the evolution of the world and all that is therein--of
a universal process of Becoming--we recognise that at an uncertain time
the earth was framed, that living organisms appeared by and by, that by
and by some of these exhibited mental as well as bodily life, and that
finally man emerged, a rational and social person. This is a convenient
and unified retrospect, but when we go further and say that all this
evolution is expressible in one descriptive formula whose terms are
mechanical, we are going further than our present knowledge warrants.
Even Spencer did not really carry his evolution-formula throughout, for
he admitted that "the development of Mind itself cannot be explained by
a series of deductions from the Persistence of Force," though he covered
his retreat by the suggestion that Mind is the subjective concomitant of
the objective nervous system which has been evolved according to
formula. But even if this _tour de force_ seemed legitimate, we should
still be unable to accept a universal formula of Evolution in terms of
mechanism. For we are not at present able to think of the facts of
bodily life in terms of mechanical categories. Thus, in short, when we
enter the chariot of Spencer's Evolution-formula, and attempt to make an
intellectual journey--"one and continuous" from the primitive nebula to
human society, we confess to suffering serious joltings. We must admit
that on that chariot at least we have never been able to arrive. Let us
refer briefly to three of the worst jolts--at the origin of Life, at the
origin of Mind, at the origin of Man.
_Origin of Life._--It is much to be regretted that Spencer "had to omit
that part of the System of Philosophy, which deals with Inorganic
Evolution. Two volumes are missing." The closing chapter of the second
volume was to have dealt with "the evolution of organic matter--the step
preceding the evolution of living forms." It is tantalising to learn
that he habitually carried with him in thought the contents of this
unwritten chapter, for it would certainly have been interesting reading.
He did, however, give us some hint of his views.
First of all negatively, Spencer did not believe in any alleged cases of
spontaneous generation; he did not believe that any creature like an
Infusorian could arise from not-living matter; he did not believe in an
"absolute commencement of organic life," or in a "first organism." But
just as the chemist is able to build up complex organic compounds from
simple substances, so Spencer supposed that organic compounds were
evolved in nature. He supposed the evolution of some substance like
protein, which is capable of existing in many isomeric forms, and of
forming with itself and other elements, substances yet more intricate in
composition. "To the mutual influences of its metamorphic forms under
favouring conditions, we may ascribe the production of the still more
composite, still more sensitive, still more variously-changeable
portions of organic matter, which, in masses more minute and simpler
than existing Protozoa, displayed actions verging little by little into
those called vital." By a continuance of the process, the nascent life
displayed became gradually more pronounced.
No one who is aware of recent achievements in chemical synthesis, or of
the recent "vitalising" of the concept of matter, or of the apparent
simplicity of life in its humblest expressions, will seek to foreclose
the question of the possible origin of living matter from not-living
matter. The conclusion which most biologists accept is, that while there
is no known evidence of not-living matter giving origin to living
organisms, this does not exclude (_a_) the possibility that this once
took place, or (_b_) the possibility that it may be made to take place
again. It must always be remembered, however, that there is a great gap
between a drop of living matter and an integrated living organism. We
may firmly say that if living matter was once evolved from not-living
matter, it must have been the outcome of long preparatory processes,
that if it occurred, we cannot at present suggest "how" except in the
vaguest way, and that if we knew it had occurred we should still be
unable to _explain the organism_ in terms of its antecedents.
_Evolution of Mind._--Spencer speaks of the evolution-process as one and
continuous throughout, but he felt, as other thorough-going
evolutionists feel, that the emergence of psychical phenomena is a
difficulty in the way of unified formulation.
"Let it be granted that all existence distinguished as objective, may be
resolved into the existence of units of one kind. Let it be granted that
every species of objective activity may be understood as due to the
rhythmical motions of such ultimate units; and that among the objective
activities so understood, are the waves of molecular motion propagated
through nerves and nerve-centres. And let it further be granted that
all existence distinguished as subjective, is resolvable into units of
consciousness similar in nature to those which we know as nervous
shocks; each of which is the correlative of a rhythmical motion of a
material unit, or group of units. Can we then think of the subjective
and objective activities as the same? Can the oscillation of a molecule
be represented in consciousness side by side with a nervous shock, and
the two be recognised as one? No effort enables us to assimilate them.
That a unit of feeling has nothing in common with a unit of motion,
becomes more than ever manifest when we bring the two into
juxtaposition" (_Principles of Psychology_, i. p. 158).
He concluded that "there is not the remotest possibility of interpreting
Mind in terms of Matter." Since our "ideas of Matter and Motion, merely
symbolic of unknowable realities, are complex states of consciousness
built out of units of feeling," "it seems easier to translate so-called
Matter into so-called Spirit, than to translate so-called Spirit into
so-called Matter, which latter is, indeed, wholly impossible."
The obvious difficulty, of which Spencer was well aware, is "how mental
evolution is to be affiliated on Evolution at large, regarded as a
process of physical transformation?
"Specifically stated, the problem is to interpret mental evolution in
terms of the redistribution of Matter and Motion. Though under its
subjective aspect Mind is known only as an aggregate of states of
consciousness, which cannot be conceived as forms of Matter and Motion,
and do not therefore necessarily conform to the same laws of
redistribution; yet under its objective aspect, Mind is known as an
aggregate of activities manifested by an organism--is the correlative,
therefore, of certain material transformations, which must come within
the general process of material evolution, if that process is truly
universal. Though the development of Mind itself cannot be explained by
a series of deductions from the Persistence of Force, yet it remains
possible that its obverse, the development of physical changes in a
physical organ, may be so explained; and until it is so explained, the
conception of mental evolution as a part of Evolution in general,
remains incomplete" (_Principles of Psychology_, i. p. 508).
Therefore Spencer passes to discuss the genesis of nervous systems and
nervous functions, and by treating Mind as a mere aspect or
epiphenomenon, eventually gets "an adequate explanation of nervous
evolution, and the concomitant evolution of Mind," the Ultimate Reality
being always postulated as the amalgam.
"See then our predicament. We can think of Matter only in terms of Mind.
We can think of Mind only in terms of Matter, when we have pushed our
explorations of the first to the uttermost limit, we are referred to the
second for a final answer; and when we have got the final answer of the
second, we are referred back to the first for an interpretation of it.
We find the value of _x_ in terms of _y_; then we find the value of _y_
in terms of _x_; and so on we may continue for ever without coming
nearer to a solution. The antithesis of subject and object, never to be
transcended while consciousness lasts, renders impossible all knowledge
of that Ultimate Reality in which subject and object are united"
(_Principles of Psychology_, i. 627).
_Ascent of Man._--Spencer was careful to say that it is not necessary to
suppose "an absolute commencement of social life" or "a first social
organism." But an ascent has to be accounted for however gradual the
inclined plane may be, and like the origin of life, and the evolution of
mind, the ascent of man to the level of a rational and social person is
a very difficult problem, to the solution of which Spencer paid
relatively little attention.
From our frankly biological point of view there seems considerable
warrant for the suggestion that Man arose as a saltatory or transilient
variation or "sport" in a gregarious Simian stock, which was not too
hard-pressed by a struggle for subsistence either as regards food or
climate, which was not too severely menaced by ever-persecuting stronger
foes, which lived in conditions implying some measure of temporary
isolation, in-breeding, and daily "brain-stretching" education. It seems
likely that the transilient advance was in the direction of increased
cerebral complexity, associated with greater freedom of speech, and a
strengthened sense of kinship. It may be imagined that the advance
occurred in times of relative peace and in a stimulating environment,
where the seasons were well-defined, or where recurrent vicissitudes
gave an advantage to memory and capacity for prevision.
Various useful suggestions have been made as to the possible factors in
the evolution of man. (_a_) When the incipient man with his growing
brain got on to his hind-legs, and walked more or less erect upon the
earth, the new attitude, however prompted, would leave the hands more
free for manipulation, for using a stone, a tool, or a weapon, for
feeling round things and appreciating their three dimensions, it would
react on other parts of the body, such as the spinal column, the pelvis,
and perhaps even the larynx. In his address to the Anthropological
Section of the British Association in 1893, Dr Robert Munro directed
attention to three propositions: (1) the mechanical and physical
advantages of the erect position, (2) the consequent differentiation of
the limbs into hands and feet, and (3) the causal relation between this
and the development of the brain.
(_b_) Fiske and others have called attention to the prolonged helpless
infancy, so characteristic of human offspring, and illustrated in a less
marked degree among Simian races. It would tend, in conditions not too
severe, to tighten the family bond, and to evolve gentleness and a habit
of altruistic outlook. It should also be remembered that the type of
brain which characterises man is marked by its relative poverty in
inherited instinct and by its eminent educability.
(_c_) The influence of the family was probably an important factor,
fostering sympathy and mutual aid, prompting talk and division of
labour. Even in early days, children would educate their parents. It
must be remembered that many animals exhibit family life, and also
pairing for prolonged periods or for life.
(_d_) If we grant the incipient man a growing, plastic, and restless
brain, a strong feeling of kinship, some family ties, an erect attitude,
the habit of using his hands and voice, all of which the anthropoid
analogy suggests, and if we deny him sufficient physical strength to
keep his foothold by virtue of that alone, then it seems more than a
platitude to say that natural selection would favour the development of
wits, and not only of wits, but in the widest sense (partly through
sexual selection) of "love," which became a new source of strength.
(_e_) With the development of tool-using and sentence-making, with
recognition of the seasons as a fundamental illustration of the
uniformity of nature, with the gaining of a firmer foothold in the
struggle for existence, with slowly increasing altruism and sociality,
and with the occasional emergence of the genius, there might gradually
arise--in permanent products, in symbols and songs, in traditions and
customs--an external heritage, which, it appears to us, has been the
most potent factor in securing and furthering human evolution.
Ignorant as we are as to the factors in human evolution, there is a
convergence of various lines of evidence towards the conclusion that man
must have come of a social stock. It is difficult to conceive of his
survival on any other supposition. In a deeper sense, perhaps, than
Rousseau thought of, it seems true that Man did not make Society,
Society (pre-human) made Man.
By some means or other, probably along various paths--through
kinship-sympathies, through linguistic bonds, for economic or
life-and-death reasons, man became definitely social, and a new order of
things began, which Spencer has pictured with great skill. Just as it
was a new event in the history of Hymenopterous insects when ants made
an ant-hill, or bees a natural hive, so it was a new event in the
history of Man when unified societary groups came into being.
Now all this is vague, and, it may be, unconvincing; but we are not
aware that Spencer had any further light to throw on the problem--a
problem so difficult that Alfred Russel Wallace, the Nestor among living
evolutionists, has declared his conviction that the development of man's
higher qualities cannot be conceived without postulating "spiritual
influx." Our point at present is that the difficulties are greater than
Spencer publicly recognised, and that his formula of evolution is not
only too remotely abstract to be relevant, but that it is in its
mechanical phrasing quite inapplicable.
_The Scientific Position._--The idea of organic evolution suggests--that
the forms of life have had a natural history, that they have descended
from a far-distant relatively simple ancestry, that they have risen from
level to level throughout many millions of years just as individual
animals in their development rise from level to level in a few days or
months or years. It is the only scientific conception we have of the
Becoming of the world of life.
The theory of organic evolution raises this modal interpretation into a
causal interpretation by disclosing the factors--such as Variation and
Selection--in the long process. To some minds, the known factors appear
inadequate to describe the process, especially in relation to the
emergence of mental life and the ascent of man. Thus an attempt is often
made to sit on both sides of the fence, accepting scientific factors
for what they are worth, but eking them out by postulating
"ultra-scientific" causes. This procedure, however, lands in mental
confusion; it is like trying to speak two languages at once. It is also
very premature.
When we extend the concept of evolution to the inorganic world, we find
that it applies there also, that it enables us to resume the history of
the solar system as a whole, and of the earth in particular in a
convenient formula. Here again we are aware of factors of evolution,
which enable us to give a causal interpretation of how the inanimate
world came to be as it is. The factors are not the same as those
verifiable in organic evolution; they are in terms of the laws of motion
and other physical concepts.
Again the idea of evolution may be applied to the forms of mental life
and to the forms of social life, and in these realms the factors are not
the same as those used in interpreting the history of organisms
(objectively considered) or the history of inanimate systems.
In all cases the general concept of evolution is the same--the idea of
natural progressive change--but the factors are different. The reason
for this is that the organism is very different from a planet or a
crystal, that mind is quite different from metabolism, that a society is
more than the sum of its parts.
It is quite plain that the sociological evolutionist will not advance
far if he disregards the concept of the social organism, if he shuts his
eyes to the fact that a societary form, however simple, is an integrate;
not a mere congeries of persons, but a unity with a life and mind of its
own. Yet he may quite consistently try to trace the emergence of
societary forms from a simply gregarious stock, and that again from
entirely non-social organisms.
In the same way the psychological evolutionist will not advance far if
he disregards the distinctiveness of mental life, with principles of
its own quite different from those of the bodily life with which it is
inextricably associated. That is to say he must be more than a
physiologist of the nervous system.
So, the biological evolutionist must admit that he cannot trace the
evolution of organisms in terms of the concepts which suffice for
inanimate systems. In so doing he does not dogmatically say that the
activity of organisms _cannot_ be described in terms of mechanism, he
only says that it has not been done; he only says that neither physics
nor physiology is at present within sight of deducing the laws of motion
of organic corpuscles from the laws of motion of other corpuscles.
There is no reason why he should stand aloof from the theory that
inorganic and organic evolution are continuous, in other words from the
theory of the spontaneous generation of living matter at an appropriate
time in the Earth's history--a theory which is suggested by many facts.
If that is a legitimate theory it increases our respect for what we call
the inanimate, but it does not make our biological evolutionism any
easier, nor are we any nearer explaining life. The organism remains what
it is, a living creature with a behaviour which we are unable to
redescribe in terms of mechanism. And inanimate matter remains what it
is, except that we should be able to say definitely that it had once
given origin to living matter and might conceivably do so again. There
would be no gain in adding to the properties of matter a mysterious
"capacity-of-sharing-in-the-spontaneous-generation-of-life."
Let us state the position once more. When one of the higher animals, in
the course of its development, reaches a certain, or rather uncertain,
degree of differentiation, its functioning becomes behaviour; its
activities are such that we cannot interpret them without using
psychical terms, such as awareness or intelligence. This expression of
fuller life is associated with the increased development of the nervous
system, and we have no knowledge of any psychical life apart from
nervous metabolism. Yet we remain quite unable to think of any way by
which the metabolism of nerve-cells gives rise to what we know in
ourselves as sensations or perceptions, ideas or feelings. Therefore
while we see no reason to doubt the continuity of the individual
development, we recognise as fact of experience that the merely sentient
embryo becomes a thoughtful child, whose behaviour cannot be formulated
in terms of our present biological or our present mechanical categories.
And as it is with the individual development, so it is with the
evolution of organisms; when they exhibit a certain, or rather
uncertain, degree of differentiation they behave in a way which we
cannot interpret without using psychical terms. We know of very simple
forms whose whole behaviour seems to be summed up in one reflex action,
at least if there is more we cannot detect it; we know of other
unicellular animals whose behaviour is such that we are forced to say
that they seem to pursue the method of trial and error; and from that
level we know of a long inclined plane leading up to very alert
intelligence. Again we see no reason to doubt the continuity of the
process, though we recognise that at a certain level of organisation the
biological categories of metabolism and the like are no longer
sufficient to formulate the facts. How it is that the activity of the
nervous system does express itself in such a way, that we must use a new
set of terms--psychical ones--to cover the facts of behaviour, no one
has at present any conception. A living creature behaves in such a way
that we cannot interpret what it does in terms of the motions of the
organic corpuscles which compose it. We do not know how to formulate in
physical terms its growth, its development, its power of effective
response, its co-ordination of activities. Therefore we introduce a
special series of biological concepts, without denying that a greater
unity of formulation may some day be attained either by a further
simplification of the biological concepts or by some change in the
physical concepts, such as, indeed, seems coming about at present.
But again, a living creature behaves in such a way that our biological
concepts are insufficient to formulate its behaviour. We do not know how
to interpret what it does without psychological concepts of thinking,
feeling, and willing. It is possible that here, too, a greater unity of
formulation may some day be attained either by a further simplification
of the psychological concepts or by some change in the biological
concepts. But sufficient unto the day is the science thereof.
FOOTNOTES:
[10] Quoted from Prof. W. H. Hudson's _Introduction to the Philosophy of
Herbert Spencer_.
[11] See Karl Pearson. _The Grammar of Science_, p. 329.