CHAPTER XVII.
SUMMARY AND CONCLUSION.
§ 138. In the chapter on “Laws in general,” after delineating the progress of mankind in recognizing uniformities of relation among surrounding phenomena—after showing how the actual succession in the establishment of different orders of co-existences and sequences, corresponds with the succession deducible à priori from the conditions to human knowledge—after showing how, by the ever-multiplying experiences of constant connections among phenomena, there has been gradually generated the conception of universal conformity to law; it was suggested that this conception will become still clearer, when it is perceived that there are laws of wider generality than any of those at present accepted.
The existence of such more general laws, is, indeed, almost implied by the ensemble of the facts set forth in the above-named chapter; since they make it apparent, that the process hitherto carried on, of bringing phenomena under fewer and wider laws, has not ceased, but is advancing with increasing rapidity. Apart, however, from evidence of this kind, the man of science, hourly impressed with new proof of uniformity in the relations of things, until the conception of uniformity has become with him a necessity of thought, tacitly entertains the conclusion that the minor uniformities which Science has thus far established, will eventually be merged in uniformities that are universal. Taught as he is by every observation and experiment, to regard phenomena as manifestations of Force; and learning as he does to contemplate Force as unchangeable in amount; there tends to grow up in him a belief in unchangeable laws common to Force under all its manifestations. Though he may not have formulated it to himself, he is prepared to recognize the truth, that, being fixed in quantity, fixed in its two ultimate modes of presentation (Matter and Motion), and fixed in the conditions under which it is presented (Time and Space); Force must have certain equally fixed laws of action, common to all the changes it produces.
Hence to the classes who alone are likely to read these pages, the hypothesis of a fundamental unity, extending from the simplest inorganic actions up to the most complex associations of thought and the most involved social processes, will have an à priori probability. All things being recognized as having one source, will be expected to exhibit one method. Even in the absence of a clue to uniformities co-extensive with all modes of Force, as the mathematical uniformities are co-extensive with Space and Time, it will be inferred that such uniformities exist. And thus a certain presumption will result in favour of any formula, of a generality great enough to include concrete phenomena of every order.
§ 139. In the chapters on the “Law of Evolution,” there was set forth a principle, which, so far as accessible evidence enables us to judge, possesses this universality. The order of material changes, first perceived to have certain constant characteristics in cases where it could be readily traced from beginning to end, we found to have these same characteristics in cases where it could be less readily traced; and we saw numerous indications that these same characteristics were displayed during past changes of which we have no direct knowledge. The transformation of the homogeneous into the heterogeneous, first observed by naturalists to be exhibited during the development of every plant and animal, proved to be also exhibited during the development of every society; both in its political and industrial organization, and in all the products of social life,—language, science, art, and literature. From the disclosures of geology, we drew adequate support for the conclusion, that in the structure of the Earth there has similarly been a progress from uniformity, through ever-increasing degrees of multiformity, to the complex state which we now see. And on the assumption of that nebular origin to which so many facts point, we inferred that a like transition from unity to variety of distribution, must have been undergone by our Solar System; as well as by that vast assemblage of such systems constituting the visible Universe. This definition of the metamorphosis, first asserted by physiologists of organic aggregates only, but which we thus found reason to think, holds of all other aggregates, proved on further inquiry to be too wide. Its undue width was shown to arise from the omission of certain other characteristics, that are, not less than the foregoing one, displayed throughout all kinds of Evolution. We saw that simultaneously with the change from homogeneity to heterogeneity, there takes place a change from indefiniteness of arrangement to definiteness of arrangement—a change everywhere equally traceable with that which it accompanies. Further consideration made it apparent, that the increasing definiteness thus manifested along with increasing heterogeneity, necessarily results from increasing integration of the parts severally rendered unlike. And thus we finally reached the conclusion, that there has been going on throughout an immeasurable past, is still going on, and will continue to go on, an advance from a diffused, indeterminate, and uniform distribution of Matter, to a concentrated, determinate, and multiform distribution of it.
At a subsequent stage of our inquiry, we discovered that this progressive change in the arrangement of Matter, is accompanied by a parallel change in the arrangement of Motion—that every increase in the structural complexity of things, involves a corresponding increase in their functional complexity. It was shown that along with the integration of molecules into masses, there arises an integration of molecular motion into the motion of masses; and that as fast as there results variety in the sizes and forms of aggregates and their relations to incident forces, there also results variety in their movements. Whence it became manifest, that the general process of things is from a confused simplicity to an orderly complexity, in the distribution of both Matter and Motion.
It was pointed out, however, that though this species of transformation is universal, in the sense of holding throughout all classes of phenomena, it is not universal in the sense of being continued without limit in all classes of phenomena. Those aggregates which exhibit the entire change from uniformity to multiformity of structure and function, in comparatively short periods, eventually show us a reverse set of changes: Evolution is followed by Dissolution. The differentiations and integrations of Matter and Motion, finally reach a degree which the conditions do not allow them to pass; and there then sets in a process of disintegration and assimilation, of both the parts and the movements that were before growing more united and more distinct.
But under one or the other of these processes, all observable modifications in the arrangement of things may be classed. Every change comes under the head of integration or disintegration, material or dynamical; or under the head of differentiation or assimilation, material or dynamical; or under both. Each inorganic mass is either undergoing increase by the combination with it of surrounding elements for which its parts have affinity; or undergoing decrease by the solvent and abraiding action of surrounding elements; or both one and the other in varied succession and combination. By perpetual additions and losses of heat, it is having its parts temporarily differentiated from each other, or temporarily assimilated to each other, in molecular state. And through the actions of divers agents, it is also undergoing certain permanent molecular re-arrangements; rendering it either more uniform or more multiform in structure. These opposite kinds of change, thus vaguely typified in every surrounding fragment of matter, are displayed in all aggregates with increasing distinctness in proportion as the conditions essential to re-arrangement of parts are fulfilled. So that universally, the process of things is either in the one direction or the other. There is in all cases going on that ever-complicating distribution of Matter and Motion which we call Evolution; save in those cases where it has been brought to a close and reversed by what we call Dissolution.