First Principles · Herbert Spencer
CHAPTER III. THE LAW OF EVOLUTION, CONTINUED.
And so we find that while Evolution is a transformation of the homogeneous into the heterogeneous, and of the indefinite into the definite, it is also a transformation of the incoherent into the coherent. Along with the differentiation shown in increasing contrasts of parts with each other, there goes on an integration, by which the parts are rendered distinct units, as well as closely united components of one whole. These clauses here added to the definition, are essential ones; not only as being needful to distinguish Evolution from that which is not Evolution, but likewise as being needful to express all which the idea of Evolution includes. Progressive integration with the growing definiteness necessarily resulting from it, is of co-ordinate importance with the progressive differentiation before dwelt upon—nay, from one point of view, may be held of greater importance. For organization, in which what we call Evolution is most clearly and variously displayed, consists even more in the union of many parts into one whole, than in the formation of many parts. The Evolution which we see throughout inorganic nature, is lower than that which organic nature exhibits to us, for the especial reason that the mutual dependence of parts is extremely indefinite, even when traceable at all.
In an amorphous mass of matter, you may act mechanically or chemically upon one part without appreciably affecting the other parts. Though their electrical or thermal states may be for the moment altered, their original states are soon resumed. Even in the highest inorganic aggregation—a crystal—the apex may be broken off and leave the rest intact: the only clear evidence of mutual dependence of parts, being, the ability of the crystal to regenerate its apex if replaced in the solution from which it was formed. But the constituent parts of organic bodies can severally maintain their existing states, only while remaining in connexion. Even in the lowest living forms, mutilation cannot be carried beyond a certain point without decomposition ensuing. As we advance through the higher up to the highest forms, we see a gradual narrowing of the limits within which the mutilation does not cause destruction: a progressive increase of mutual dependence or integration which is, at the same time, the condition to greater functional perfection. In societies this truth is equally manifest. That the component units slowly segregate into groups of different ranks and occupations, is a fact scarcely more conspicuous than is the fact that these groups are necessary to each other’s existence.
And we cannot contemplate the still-progressing division of labour, without seeing that the interdependence becomes ever greater as the evolution becomes higher. It remains only to point out definitely, what has been already implied, that these several forms of change which have been successively described as making up the process of Evolution, are not in reality separate forms of change, but different aspects of the same change. Intrinsically the transformation is one and indivisible. The establishment of differences that become gradually more decided, is evidently but the beginning of an action which cannot be pushed to its extreme without producing definite divisions between the parts, and reducing each part to a separate mass. But with our limited faculties, it is not possible to take in the entire process at one view; nor have we any single terms by which the process can be described. Hence we are obliged to contemplate each of its aspects separately, and to find a separate expression for its characteristic. Having done this, we are now in a position to frame a true idea of Evolution. Combining these partial definitions we get a complete definition, which may be most conveniently expressed thus—_Evolution is a change from an indefinite, incoherent homogeneity, to a definite, coherent heterogeneity; through continuous differentiations and integrations._ It may perhaps be remarked that the last of these clauses is superfluous; since the differentiation and integration are implied in the first clause. This is true: the transition which the first clause specifies, is impossible save through the process specified in the second. Nevertheless, a mere statement of the two extreme stages with which Evolution begins and ends, omitting all reference to changes connecting them, leaves the mind with but an incomplete idea. The idea becomes much more concrete when these changes are described. Hence, though not logically necessary, the second clause of the definition is practically desirable.
Before closing the chapter, a few words must be added respecting certain other modes of describing Evolution. Organic bodies, from the changes of which the idea of Evolution has arisen, and to the changes of which alone it is usually applied, are often said to progress from simplicity to complexity. The transformation of the simple into the complex, and of the homogeneous into the heterogeneous, are used as equivalent phrases; or, if any difference is recognized between them, it is to the advantage of the first, which is held to be the more specific. After what has been said, however, it must be obvious that Evolution cannot be thus adequately formulated. No hint is given of that increased definiteness which we have found to be a concomitant of development. Nor is there anything implying the greater mutual dependence of parts. Nevertheless, the brevity of the expression gives it a value for ordinary purposes; and I shall probably hereafter frequently use it, both in those cases where more precise language is not demanded, and in those cases where it indicates the particular aspect of Evolution referred to. Another description frequently given of Evolution, is, that it is a change from the general to the special.
The more or less spherical germ from which every organism, animal and vegetal, proceeds, is comparatively general: alike in the sense that in appearance and chemical nature it is very similar to all other germs; and also in the sense that its form is less markedly distinguished from the average forms of objects at large, than is that of the mature organism—a contrast which equally holds of internal structure. But this progress from the more general to the more special, is rather a derivative than an original characteristic. An increase of speciality being really an increase in the number of attributes—an addition of traits not possessed by bodies that are in other respects similar—is a necessary result of multiplying differentiations. In other words, general and special are subjective or ideal distinctions involved in our conceptions of classes, rather than objective or real distinctions presented in the bodies classified. Nevertheless, this abstract formula is not without its use. It expresses a fact of much significance; and one which we shall have constantly to refer to when dealing with the relations between organic bodies and their surrounding conditions.
The law of Evolution however, be it expressed in full as above, or in these shorter but less specific phrases, is essentially that which has been exhibited in detail throughout the foregoing pages. So far as we can ascertain, this law is universal. It is illustrated with endless repetition, and in countless ways, wherever the facts are abundant; and where the facts do not suffice for induction, deduction goes far to supply its place. Among all orders of phenomena that lie within the sphere of observation, we see ever going on the process of change above defined; and many significant indications warrant us in believing, that the same process of change went on throughout that remote past which lies beyond the sphere of observation. If we must form any conclusion respecting the general course of things, past, present, and future, the one which the evidence as far as it goes justifies, and the only one for which there is any justification, is, that the change from an indeterminate uniformity to a determinate multiformity which we everywhere see going on, has been going on from the first, and will continue to go on. ----- Footnote 10: Carpenter’s Prin. of Comp. Phys., p. 617.
Ideas discussed in this chapter
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