Herbert Spencer

by J. Arthur Thomson

Spencer's contribution.—Spencer was led to become an evolutionist by the workings of his own mind, influenced by Laplace's Nebular Hypothesis, by the transformist theory of Lamarck, by von Baer's law of individual development, and by Malthus's recognition of the struggle for existence in mankind. On the whole, it may be said that he came to the theory of organic evolution from above, rather than from below, from his studies on the intellectual and social evolution of man rather than from acquaintance with the biological data. Not unnaturally, therefore, he was to begin with a Lamarckian, believing in the cumulative transmission of the transforming results of use and disuse and of environmental influences.

In the essay on "a theory of Population" (1852) Spencer was within sight of one of the great doctrines of Darwinism. "From the beginning," he said, "pressure of population has been the proximate cause of progress." "The effect of pressure of population, in increasing the ability to maintain life, and decreasing the ability to multiply, is not a uniform effect, but an average one.... All mankind in turn subject themselves more or less to the discipline described; they either may or may not advance under it; but, in the nature of things, only those who do advance under it eventually survive.... For as those prematurely carried off must, in the average of cases, be those in whom the power of self-preservation is the least, it unavoidably follows that those left behind to continue the race, are those in whom the power of self-preservation is the greatest—are the select of their generation."

Here Spencer recognised the eliminative and selective effect of struggle in mankind. Why was he "blind to the fact," as he afterwards said, "that here was a universally-operative factor in the development of species"? In his Autobiography he gives two reasons for his oversight, one was his Lamarckian preconception that the inheritance of functionally-produced modifications sufficed to explain the facts of evolution. The other was, that he "knew little or nothing about the phenomena of variation," that "he had failed to recognise the universal tendency to vary."

Similarly, in his essay on "Progress: its Law and Cause" (1857), he still "ascribed all modifications to direct adaptations to changing conditions; and was unconscious that in the absence of that indirect adaptation effected by the natural selection of favourable variations, the explanation left the larger part of the facts unaccounted for" (Autobiography, i. p. 502).

In his article "Transcendental Physiology" (1857), Spencer advanced a step beyond the position occupied in his essay on "Progress." He showed that with advance in the forms of life there is an increasing differentiation of them from their environments, that integration as well as differentiation is part of the developmental process, but the leading conception of the essay was "the instability of the homogeneous." This was recognised, like "the multiplication of effects," as a cause of progress, as "a principle holding not among organic phenomena only, but among inorganic and super-organic phenomena." It was in this essay also that he began to use the word "evolution" in place of the more teleological word "progress."

In the same year (1857) Spencer again approached the idea of selection as a directive factor in evolution. In an essay on "State Tamperings with Money and Banks" he gave among other reasons for reprobating grandmotherly legislation, that "such a policy interferes with that normal process which brings benefit to the sagacious and disaster to the stupid." "The ultimate result of shielding men from the effects of folly, is to fill the world with fools." "This was a tacit assertion, recalling like assertions previously made, that the survival of the fittest operates beneficially in society."

Darwin's Origin of Species appeared in 1859, and marked another step in Spencer's evolutionism. Hitherto, though he had several times approached the idea of Natural Selection, he had "held that the sole cause of organic evolution is the inheritance of functionally-produced modifications"; now it became clear to him that he was wrong, and that the larger part of the facts cannot be due to any such cause (Autobiography, ii. 50).

In 1864 Spencer definitely sought to assimilate the Darwinian idea of Natural Selection into his system. He had become convinced that the hereditary accumulation of functional modifications could not be the sole factor in organic evolution; he had recognised the importance and efficacy of Natural Selection as a directive agency thinning and "singling" the crop of variations which is always abundant; but he had not seen how to absorb "Natural Selection" into his general physical theory of evolution. It seemed "to stand apart as an unrelated process."

"The search for congruity led first of all to perception of the fact that what Mr Darwin called 'natural selection,' might more literally be called survival of the fittest. But what is survival of the fittest, considered as an outcome of physical actions?"

Spencer's answer was that the changes constituting evolution tend ever towards a state of equilibrium; on the way to this there are stages of "moving equilibrium"; some organisms have their moving equilibrium less easily overthrown than others; these are the fittest which survive; they are, in Darwin's language, the select which nature preserves; and thus "the survival and multiplication of the select becomes conceivable in purely physical terms, as an indirect outcome of a complex form of the universal redistribution of matter and motion" (Autobiography, ii. pp. 100-1). In short, natural selection is part of the universal process towards more stable equilibrium.

When formulating his views on the classification of the sciences and his reasons for dissenting from the philosophy of Comte, Spencer pointed out that all the concrete sciences under their most general aspects give accounts of the redistributions of matter and motion; and he asked the question, What is the universal trait of all such redistributions? His answer was that "increasing integration of matter necessitates a concomitant dissipation of motion, and that increasing amount of motion implies a concomitant disintegration of matter." Thus Evolution and Dissolution appeared "under their primordial aspects," and differentiations, with resulting increase of heterogeneity, were seen to be secondary not primary traits of evolution. So he arrived at his famous definition of evolution:—"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).

Having illustrated the evolution of the evolution-theory in Spencer's mind, we pass to his final statement of the factors of organic evolution.

(1) External Factors.—He begins by pointing out that living creatures are in the grip of a complex environment, which acts on them and to which they react. And whether we think of the seasons or the climate, the soil or the sea, we find that this environment is intricately variable. Every kind of plant and animal may be regarded as for ever passing into a new environment, and with increasing fullness of life there is additional complexity in the incidence of external forces. Every increase of locomotive power, for instance, increases the multiplicity and multiformity of action and reaction between organism and environment. There are chemical, mechanical, dynamic, and animate influences which modify organisms, and as the actions of these several orders of factors are compounded, there is produced a geometric progression of changes increasing with immense rapidity. All through the ages living creatures have as it were been passing over a series of anvils on which the hammers of external forces play, with tunes of ever-increasing complexity.

(2) Internal Factors.—Passing to internal factors, Spencer started from the fact that organic matter is built up of very unstable complex molecules. "But a substance which is beyond all others changeable by the actions and reactions of the forces liberated from instant to instant within its own mass, must be a substance which is beyond all others changeable by the forces acting on it from without." In any aggregate "the relations of outside and inside, and of comparative nearness to neighbouring sources of influences, imply the reception of influences that are unlike in quantity, or quality, or both; and it follows that unlike changes will be produced in the parts thus dissimilarly acted on." Thus arise differentiations of structure, a transition from a uniform to a multiform state, a passage from homogeneity to heterogeneity, and this must go on cumulatively. For "the more strongly contrasted the parts of an aggregate become, the more different must be their reactions on incident forces, and the more unlike must be the secondary effects which these initiate. This multiplication of effects conspires, with the instability of the homogeneous, to work an increasing multiformity of structure in an organism." Thus, if the head of a bison becomes much heavier, what a multiplication of effects—mechanical and physiological—must ensue on muscles and bones and blood-vessels. One modification brings another in its train; there are secondary and tertiary effects. And as the increasing assemblage of individuals arising from a common stock is thus liable to lose its original uniformity and to grow more pronounced in its multiformity, indirect effects follow from inter-crossing and from altered competitive conditions. Moreover, as times and seasons and ages pass, the environment goes on changing, and on previous complications wrought by incident forces, new complications are continually superimposed by new incident forces. Thus there is an almost continuous movement towards heterogeneity. But how is that kind of heterogeneity insured which is required to carry on life? How is the evolution directed?

(3) Direct Equilibration.—How is it that action and reaction between the organism and its environment bring about effective adaptations? Spencer's answer is that every change is towards a balance of forces, and can never cease until a balance of forces is reached. "Any unequilibrated force to which an aggregate is subject, if not of a kind to overthrow it altogether, must continue modifying its state until an equilibrium is brought about." Thus "there go on in all organisms, certain changes of function and structure that are directly consequent on changes in the incident forces—inner changes by which the outer changes are balanced, and the equilibrium restored." "That a new external action may be met by a new internal action, it is needful that it shall either continuously or frequently be borne by the individuals of the species, without killing or seriously injuring them; and shall act in such a way as to affect their functions." But as many of the environing agencies to which organisms have to be adjusted, either do not immediately affect the functions at all, or else affect them in ways that prove fatal, there must be at work some other process which equilibrates the actions of organisms with the actions they are exposed to.

(4) Indirect Equilibration.—There are many very precise adaptations, e.g. in the not-living hard parts of many animals, which no ingenuity can interpret as the directly equilibrated results of incident forces. To interpret mimicry as due to direct equilibration is hopeless. Therefore, Spencer passed to what he called "indirect equilibration."

"Besides those perturbations produced in any organism by special disturbing forces there are ever going on many others—the reverberating effects of disturbing forces previously experienced by the individual, or by ancestors; and the multiplied deviations of function so caused implied multiplied deviations of structure." A directly induced modification induces correlated secondary and tertiary perturbations, and when two differently endowed parents are mated they will bequeath to their joint offspring "compound perturbations of function and compound deviations of structure, endlessly varied in their kinds and amounts." In short, Spencer postulated variations as indirect results of the action of incident forces.

As the individuals of a species are thus necessarily made unlike in countless ways and degrees, then amongst them "some will be less liable than others to have their equilibria overthrown by a particular incident force previously unexperienced... Inevitably, some will be more stable than others when exposed to this new or altered factor. That is to say, those individuals whose functions are most out of equilibrium with the modified aggregate of external forces, will be those to die; and those will survive whose functions happen to be most nearly in equilibrium with the modified aggregate of external forces. But this survival of the fittest implies the multiplication of the fittest. Out of the fittest thus multiplied there will, as before, be an overthrowing of the moving equilibrium wherever it presents the least opposing force to the new incident force. And by the continual destruction of the individuals least capable of maintaining their equilibria in presence of this new incident force, there must eventually be reached an altered type completely in equilibrium with the altered conditions." In short, Spencer incorporated the characteristic Darwinian idea of Natural Selection operating upon a crop of variations, and thus securing by the survival of the fittest an indirect equilibration.

In an ingenious way, to which we have already alluded, Spencer assimilated the theory of Natural Selection with his own formula of evolution. Let us recapitulate his argument. All the processes by which organisms are refitted to their ever-changing environments must be equilibrations of one kind or another, for change of every order is towards equilibrium, and life itself is a moving equilibrium between inner and outer actions—a continual adjustment of internal relations to external relations. The process called Natural Selection is literally a survival of the fittest; and "that is a maintenance of the moving equilibrium of the functions in presence of outer actions; implying the possession of an equilibrium which is relatively stable in contrast with the unstable equilibria of those which do not survive." ... "The conception of Natural Selection is manifestly one not known to physical science: its terms are not of a kind physical science can take cognisance of. But here we have found in what manner it may be brought within the realm of physical science."