University of Virginia Library

Chapter 14
The Law of Evolution

§107. Deduction has now to be verified by induction. Thus far the argument has been that all sensible existences must, in some way or other and at some time or other, reach their concrete shapes through processes of concentration; and the facts named have been named merely to clarify the perception of this necessity. But we have not arrived at that unified knowledge constituting Philosophy, until we have seen how existences of all orders do exhibit a progressive integration of Matter and accompanying loss of Motion. Tracing, so far as we may by observation and inference, the objects dealt with by the Astronomer and the Geologist, as well as those which Biology, Psychology, and Sociology treat of, we have to consider what direct proof there is that the Cosmos, in general and in detail, conforms to this law.

Throughout the classes of facts successively contemplated, attention will be directed not so much to the truth that every aggregate has undergone, or is undergoing, integration, as to the further truth that in every more or less separate part of every aggregate, integration has been, or is, in progress. Instead of simple wholes and wholes of which the complexity has been ignored, we have now to deal with wholes as they actually exist — mostly made up of many members combined in many ways. And in them we shall have to trace the transformation under several forms — a passage of the total mass from a more diffused to a more consolidated state; a concurrent similar passage in every portion of it that comes to have a distinguishable individuality; and a simultaneous increase of combination among such individualized portions.

§108. Our Sidereal System by its general form, by its clusters of stars of various degrees of closeness, and by its nebulae in all stages of condensation, gives grounds for suspecting that, generally and locally, concentration is going on. Assume that its matter has been, and still is being, drawn together by gravitation, and we have an explanation of its leading traits of structure — from its solidified masses up to its collections of attenuated flocculi barely discernible by the most powerful telescopes, from its double stars up to such complex aggregates as the nubeculae. Without dwelling on this evidence, however, let us pass to the case of the Solar System.

The belief, so variously supported, that this has had a nebular genesis, is the belief that it has arisen by the integration of matter and concomitant loss of motion. Evolution, under its primary aspect, is illustrated most simply and clearly by this passage of the Solar System from a diffused incoherent state to a consolidated coherent state. While, according to the nebular hypothesis, there has been going on a gradual concentration of the Solar System as an aggregate, there has been a simultaneous concentration of each partially-independent member. The changes of every planet in passing through its stages of nebulous ring, gaseous spheroid, liquid spheroid, and spheroid externally solidified, have in essentials — dissipation of motion and aggregation of matter — paralleled the changes gone through by the general mass; and those of every satellite have done the like. Moreover, at the same time that the matter of the whole, as well as the matter of each partially-independent part, has been thus integrating, there has been the further integration implied by increasing combination among the parts. The satellites of each planet are linked with their primary into a balanced cluster, while the planets and their satellites form with the Sun, a compound group of which the members are more strongly bound together than were the far-spread portions of the nebulous medium out of which they arose.

Even apart from the nebular hypothesis, the Solar System furnishes facts having a like general meaning. Not to make much of the meteoric matter perpetually added to the Earth, and probably to the other planets, as well as, in larger quantities, to the Sun, it will suffice to name two generally-admitted instances. The one is the retardation of comets by the ethereal medium, and the inferred retardation of planets — a process which must in time, as Lord Kelvin argues, bring comets, and eventually planets, into the Sun. The other is the Sun's still-continued loss of motion in the shape of radiated heat; accompanying the still-continued integration of his mass.

§109. To astronomic evolution we pass without break to the evolution which, for convenience, we separate as geologic. The history of the Earth, as traced out from the structure of its crust, carries us back to that molten state which the nebular hypothesis implies; and, as before pointed out (§69), the changes called igneous are accompaniments of the advancing consolidation of the Earth's substance and loss of its contained motion. The general effects and the local effects must be briefly exemplified.

Leaving behind the time when the more volatile elements now existing as solids were kept by the high temperature in a gaseous form, we may begin with the fact that until the Earth's surface had cooled far below red heat, the mass of water at present covering three-fifths of it, must have existed as vapour. This enormous volume of unintegrated liquid became integrated as fast as dissipation of the Earth's contained motion allowed; leaving, at length, a comparatively small portion uncondensed, which would condense but for the unceasing absorption of molecular motion from the Sun. In the formation of the Earth's crust we have a similar change similarly caused. The passage from a thin solid film, everywhere fissured and movable on the subjacent molten matter, to a crust so thick and strong as to be but now and then very slightly dislocated by disturbing forces, illustrates the process. And while, in this superficial solidification, we see under one form how concentration accompanies loss of contained motion, we see it under another form in that diminution of the Earth's bulk implied by superficial corrugation.

Local or secondary integrations have advanced along with this general integration. A molten spheroid merely skinned over with solid matter, could have presented nothing beyond small patches of land and water. Differences of elevation great enough to form islands of considerable size, imply a crust of some rigidity; and only as the crust grew thick could the land be united into continents divided by oceans. So, too, with the more striking elevations. The collapse of a thin layer round its cooling and contracting contents, would throw it into low ridges. The crust must have acquired a relatively great depth and strength before extensive mountain systems of Vast elevation became possible: continued integration of it made possible great local integrations. In sedimentary changes a like progress is inferable. Denudation acting on the small surfaces exposed during early stages, would produce but small local deposits. The collection of detritus into strata of great extent, and the union of such strata into extensive "systems," imply wide surfaces of land and water, as well as subsidences great in both area and depth; so that integrations of this order must have grown more pronounced as the Earth's crust thickened.

§110. Already we have recognized the fact that the evolution of an organism is primarily the formation of an aggregate, by the continued incorporation of matter previously spread through a wider space. Every plant grows by taking into itself elements that were before diffused, and every animal grows by re-concentrating these elements previously dispersed in surrounding plants or other animals. Here it will be proper to complete the conception by pointing out that the early history of a plant or animal, still more clearly than its later history, shows us this fundamental process. For the microscopic germ of each organism undergoes, for a long time, no other change than that implied by absorption of nutriment. Cells embedded in the stroma of an ovarium, become ova by little else than continued growth at the expense of adjacent materials. And when, after fertilization, a more active evolution commences, its most conspicuous trait is the drawing-in, to a germinal centre, of the substance which the ovum contains.

Now, however, our attention must be directed mainly to the secondary integrations which accompany the primary integration. We have to observe how, along with the formation of a larger mass of matter, there goes on a gathering together and consolidation of this matter into parts, as well as a closer combination of the parts. In the mammalian embryo the heart, at first a long pulsating blood-vessel, by-and-by twists upon itself and integrates. The bile-cells constituting the rudimentary liver, do not simply become different from the wall of the intestine in which they at first lie, but, while accumulating, they diverge from it and consolidate into an organ. The anterior portion of the cerebrospinal axis, at first continuous with. the rest, and not markedly distinguished from it, undergoes a union of its rapidly-growing parts; and at the same time the resulting head folds into a mass marked off from the spine. The like process, variously exhibited in other organs, is meanwhile exhibited by the body as a whole; which becomes integrated somewhat in the same way that an outspread handkerchief and its contents become integrated when its edges are drawn in and fastened to make a bundle. Kindred changes go on after birth, and continue even up to old age. In man, that solidification of the bony framework which, during childhood, is seen in the coalescence of portions of the same bone ossified from different centres, is afterwards seen in the coalescence of bones that were originally distinct. The appendages of the vertebrae join with the vertebral centres to which they belong: a change not completed until towards thirty. At the same time the epiphyses, formed separately from the main bodies of their respective bones, have their cartilaginous connexions turned into osseous ones — are fused to the masses beneath them. The component vertebra of the sacrum, which remain separate till about the sixteenth year, then begin to unite; and in ten or a dozen years more their union is complete. Still later occurs the junction of the coccygeal vertebra; and there are some other bony unions which remain unfinished unless advanced age is reached. To which add that the increase of density, going on throughout the tissues at large during life, is the formation of a more fully integrated substance.

The species of change thus illustrated, may be traced in all animals. That mode of it which consists in the union of similar parts originally separate, has been described by Milne-Edwards and others, as exhibited in various Invertebrata; though it does not seem to have been included by them as an essential trait of organic development. We shall, however, see that local integration is an all-important part of this process, when we find it not only in the successive stages passed through by every embryo, but also in ascending from the lower creatures to the higher. As manifested in either way, it goes on both longitudinally and transversely; under which different forms we may conveniently consider it. Of longitudinal integration, the sub-kingdom Annulosa supplies abundant examples. Its lower members, such as worms and next to them myriapods, are mostly characterized by the great numbers of their segments; reaching in some cases to several hundreds. But in the higher divisions — crustaceans, insects, and arachnids — this number is reduced to twenty-two, thirteen, or even fewer; while, accompanying the reduction, there is a shortening or integration of the whole body, reaching its extreme in the crab and the spider. The significance of these contrasts, as bearing on the doctrine of Evolution, will be clear when it is observed that they are parallel to those which arise during the development of individual annulose animals. The head and thorax of a lobster form one compact box, made by the union of a number of segments which in the embryo were separable. Similarly, the butterfly shows us segments so much more closely united than they were in the caterpillar, as to be, some of them, no longer distinguishable from one another. The Vertebrata again, throughout their successively higher classes, furnish like instances of longitudinal union. In most fishes, and in limbless reptiles, none of the vertebra coalesce. In most mammals and in birds, a variable number of vertebra become fused to form the sacrum; and in the higher apes and in man, the caudal vertebra also lose their separate individualities in a single os coccygis. That which we may distinguish as transverse integration, is well illustrated among the Annulosa in the development of the nervous system. Leaving out those most degraded forms which do not present distinct ganglia, we find that the lower annulose animals, in common with the larva of the higher, are severally characterized by a double chain of ganglia running from end to end of the body; while in the more perfectly-formed annulose animals, the two chains unite into a single chain. Mr. Newport has described the course of this concentration in insects, and by Rathke it has been traced in crustaceans. During the early stages of the common cray-fish, there is a pair of ganglia to each ring. Of the fourteen pairs belonging to the head and thorax, the three pairs in advance of the mouth consolidate to form the cephalic ganglion or brain. Meanwhile, of the remainder, the first six pairs severally unite in the median line, while the rest remain more or less separate. Of these six double ganglia thus formed, the anterior four coalesce into one mass; the remaining two coalesce into another mass, and then these two masses coalesce. Here longitudinal and transverse integration go on simultaneously and in the highest crustaceans they are both carried still further. The Vertebrata exhibit transverse integration in the development of the generative system. The lowest mammals — the Monotremata — in common with birds, to which they are in many respects allied, have oviducts which towards their lower extremities are dilated into cavities, each imperfectly performing the function of a uterus. "In the Marsupialia there is a closer approximation of the two lateral sets of organs on the median line: for the oviducts converge towards one another and meet (without coalescing) on the median line; so that their uterine dilatations are in contact with each other, forming a true 'double uterus.'... As we ascend the series of 'placental' mammals, we find the lateral coalescence becoming more and complete.... In many of the Rodentia the uterus still remains completely divided into two lateral halves; whilst in others these coalesce at their lower portions, forming a rudiment of the true 'body' of the uterus in the human subject. This part increases at the expense of the lateral 'cornua' in the higher herbivora and carnivora; but even in the lower quadrumana the uterus is somewhat cleft at its summit."

Under the head of organic integrations, there remain to be noted another class of illustrations. Whether the Annulosa referred to above are or are not originally compound animals, it is unquestionable that there are compound animals among other classes of invertebrates: integration is displayed not within the limits of an individual only but by the union of many individuals. The Salpidae are composite creatures having the shape of chains joined more or less permanently; and Pyrosoma shows us a large number united into a cylinder. Moreover in the Botryllidae the merging of the individualities goes so far that instead of having separate skins they are enclosed within a common skin. Among the Cœlenterata integration produces half-fused colonies of types unlike these. There are the branched Hydrozoa in which many individuals form an aggregate in such a way as to have a common system of nutrition, while some of them undertake special functions; and much the same may be said of those compound Actinozoa which are imbedded in the calcareous frameworks we know as corals. And then in certain pelagic types, grouped as Siphonophora, the united individuals, in some cases alike, are in other cases severally transformed in adaptation to various functions; so that the component individuals, assuming the characters of different organs, become practically combined into a single organism.

From this kind of integration we pass to a kind in which the individuals are not physically united but simply associated — are integrated only by their mutual dependence. We may set down two kinds — those which occur within the same species, and those which occur between members of different species. More or less of the gregarious tendency is common among animals; and when it is marked, there is, in addition to simple aggregation, some degree of combination. Creatures that hunt in packs, or that have sentinels, or that are governed by leaders, form bodies partially united by co-operation. Among polygamous mammals and birds this mutual dependence is closer; and the social insects show us still more consolidated assemblages: some of them having their members so united that they cannot live independently How organisms in their totality are mutually dependent, and in that sense integrated, we shall see on remembering — first, that while all animals live directly or indirectly on plants, plants utilize the carbon dioxide excreted by animals; second, that among animals the flesh-eaters cannot exist without the plant-eaters; third, that a large proportion of plants can continue their respective races only by the help of insects. Without detailing the more complex connexions, which Mr. Darwin has so beautifully illustrated, it will suffice to say that the Flora and Fauna in each habitat, constitute an aggregate so far integrated that many of its species die out if placed amid the plants and animals of another habitat. And this integration, too, increases as organic evolution advances.

§111. The phenomena set down in the foregoing paragraph introduce us to others of a higher order, with which they ought, in strictness, to be grouped-phenomena which we may term super-organic. Inorganic bodies present us with certain facts. Additional facts, mostly of a more involved kind, are presented by organic bodies. There remain yet further facts, not presented by any organic body taken singly, but which result from the actions of aggregated organic bodes. Though phenomena of this order are, as we see, foreshadowed among inferior organisms, they become so conspicuous in mankind as socially united, that practically we may consider them to commence here.

In the social organism integrative changes are abundantly exemplified. Uncivilized societies display them when wandering families, such as those of Bushmen, join into tribes of considerable size. A further progress in mass results from the subjugation of weak tribes by strong ones; and in the subordination of their respective chiefs to the conquering chief. Such combinations which, among aboriginal races, are continually being formed and continually broken up, become, among superior races, relatively permanent. If we trace the stages through which our own society, or any adjacent one, has passed, we see this unification from time to time repeated on a larger scale and gaining in stability The consequent establishment of groups of vassals bound to their respective lords; the subsequent subjection of groups of inferior nobles to dukes or earls; and the still later growth of the kingly power over dukes and earls; are so many instances of increasing consolidation. This process slowly completes itself by destroying the original lines of demarcation. And of the European nations it may be further remarked, that in the tendency to form alliances, in the restraining influences exercised by governments over one another, in the system of settling international arrangements by congresses, as well as in the weakening of commercial barriers and the increasing facilities of communication, we see the beginnings of a European federation — a still larger integration that any now established.

But it is not only in these external unions of groups with groups, and of the compound groups with one another, that the general law is exemplified. It is exemplified also in unions which take place internally, as the groups become better organized. There are two orders of these, broadly distinguishable as regulative and operative. A civilized society is made unlike a savage tribe by the establishment of regulative classes-governmental, administrative, military, ecclesiastical, legal, etc., which, while they severally have their bonds of union, constituting them sub-classes, are also held together as a general class by a certain community of privileges, of blood, of education, of intercourse. In some societies, fully developed after their particular types, this consolidation into castes, and this union among the upper castes by separation from the lower eventually grow very decided: to be afterwards rendered less decided, only in cases of social metamorphosis caused by the industrial régime. The integrations seen throughout the operative or industrial organization, later in origin, are not merely of this indirect kind, but they are also direct — they show us physical approach. We have integrations consequent on the growths of adjacent parts performing like functions; as, for instance, the junction of Manchester with its calico-weaving suburbs. We have other integrations which arise when, out of several places producing a particular commodity, one gaining more and more of the business, draws to it masters and workers, and leaves the other places to dwindle; as witness the growth of the Yorkshire cloth-districts at the expense of those in the West of England; or the absorption by Staffordshire of the pottery-manufacture, and the consequent decay of establishments at Derby and elsewhere. We have those more special integrations that arise within the same city; whence result the concentration of corn-merchants about Mark Lane, of civil engineers in Great George Street, of bankers in the centre of the city. Industrial integrations which consist, not in the approximation or fusion of parts, but in the establishment of centres of connexion, are shown in the Bankers' clearing-house and the Railway clearing-house. While of yet another species are those unions which bring into relation dispersed citizens who are occupied in like ways; as traders are brought by the Exchange, and as are professional men by institutes like those of Civil Engineers, Architects, etc.

These seem to be the last of our instances. Having followed up the general law to social aggregates, there apparently remain no other aggregates to which it can apply. This, however, is not true. Among what were above distinguished as super-organic phenomena, there are sundry further groups of remarkable illustrations. Though evolutions of the various products of social activities cannot be said directly to exemplify the integration of matter and dissipation of motion, yet they exemplify it indirectly. For the progress of Language, of Science, and of the Arts, industrial and aesthetic, is an objective register of subjective changes. Alterations of structure in human beings, and concomitant alterations of structure in aggregates of human beings, jointly produce corresponding alterations of structure in all those things which humanity creates. As in the changed impress on the wax, we read a change in the seal; so in the integrations of advancing Language, Science, and Art, we see reflected certain integrations of advancing human structure, individual and social. A section must be devoted to each group.

§112. Among uncivilized races, the many-syllabled names of not uncommon objects, as well as the descriptive character of proper names, show that the words used for the less-familiar things are formed by uniting the words used for the more-familiar things. This process of composition is sometimes found in its incipient stage — a stage in which the component words are temporarily joined to signify some unnamed object, and, from lack of frequent use, do not permanently cohere. But in most inferior languages, the process of "agglutination" has gone far enough to produce some stability in the compound words: there is a manifest integration. How small is this integration, however, in comparison with that reached in well-developed languages, is shown both by the great length of the compound words used for common things and acts, and by the separableness of their elements. Certain North-American tongues illustrate this very well. In a Ricaree vocabulary extending to fifty names of common objects, which in English are nearly all expressed by single syllables, there is not one monosyllabic word. Things so familiar to these hunting tribes as dog and bow, are, in the Pawnee language, ashakish and teeragish; the hand and the eyes are respectively iksheeree and keereekoo. for day the term is shakoorooeeshairet, and for devil it is tsaheekshkakooraiwah. while the numerals are composed of from two syllables up to five, and in Ricaree up to seven. That the great length of these familiar words implies low development, and that in the formation of higher languages out of lower there is a gradual integration, which reduces the polysyllables to dissyllables and monosyllables, is an inference confirmed by the history of our own language. Anglo-Saxon steorra has been in course of time consolidated into English star, mona into moon, and nama into name. The transition through semi-Saxon is clearly traceable. Sunu became in semi-Saxon sune, and in English son; the final e of sune being an evanescent form of the original u. The change from the Anglo-Saxon plural, formed by the distinct syllable as, to our plural formed by the appended consonant s, shows the same thing: smithas in becoming smiths, and endas in becoming ends, illustrate progressive coalescence. So, too does the disappearance of the terminal an in the infinitive mood of verbs; as shown in the transition from the Anglo-Saxon cuman to the semi-Saxon cumme, and to the English come. Moreover the process has been slowly going on, even since what we distinguish as English was formed. In Elizabeth's time, verbs were still frequently pluralized by the addition of en — we tell was we tellen; and in some places this form of speech may even now be heard. In like manner the terminal ed of the past tense, has united with the word it modifies. Burn-ed has in pronunciation become burnt; and even in writing, the terminal t has in some cases taken the place of the ed. Only where antique forms in general are adhered to, as in the church-service, is the distinctness of this inflection still maintained. Further, we see that the compound vowels have been in many cases fused into single vowels. That in bread the e and a were originally both sounded, is proved by the fact that they are still so sounded in parts where old habits linger. We, however have contracted the pronunciation into bred; and we have made like changes in many other common words. Lastly, let it be noted that where the repetition is greatest, the process is carried furthest; as instance the contraction of lord (originally hlaford) into lud in the mouths of barristers; and, still better, the coalescence of God be with you into Good bye.

Besides thus exhibiting the integrative process, Language equally exhibits it throughout all grammatical development. The lowest kinds of human speech, having merely nouns and verbs without inflections, permit no such close union of the elements of a proposition as results when their relations are marked either by inflections or by connective words. Such speech is what we significantly call "incoherent." To a considerable extent, incoherence is seen in the Chinese language. "If, instead of saying I go to London, figs come from Turkey, the sun shinesthrough the air, we said, I goend London, figs comeorigin Turkey, the sun shines passage air, we should discourse after the manner of the Chinese." From this "aptotic" form, there is a transition, by coalescence, to a form in which the connexions of words are expressed by joining with them certain inflectional words. "In Languages like the Chinese," remarks Dr. Latham, "the separate words most in use to express relation may become adjuncts or annexes." To this he adds the fact that "the numerous inflexional languages fall into two classes. In one, the inflexions have no appearance of having been separate words. In the other, their origin as separate words is demonstrable." From which the inference drawn is, that the "aptotic" languages, by the more and more constant use of adjuncts, gave rise to the "agglutinate" languages, or those in which the original separateness of the inflexional parts can be traced; and that out of these, by further use, arose the "amalgamate" languages, or those in which the original separateness of the inflexional parts can no longer be traced. Strongly corroborative of this inference is the fact that, by such a process, there have grown out of the amalgamate languages, the "anaptotic" languages, of which our own is the best example — languages in which, by further consolidation, inflexions have almost disappeared, while, to express the verbal relations, new kinds of words have been developed. When we see the Anglo-Saxon inflexions gradually lost by contraction during the development of English, and, though to a less degree, the Latin inflexions dwindling away during the development of French, we cannot deny that grammatical structure is modified by integration; and seeing how clearly the earlier stages of grammatical structure are explained by it, we must conclude that it has been going on from the first.

In proportion to the degree of this integration, is the extent to which integration of another order is carried. Aptotic languages are, as already pointed out, necessarily incoherent — the elements of a proposition cannot be completely tied into a whole. But as fast as coalescence produces inflected words, it becomes possible to unite them into sentences of which the parts are so mutually dependent that no considerable change can be made without destroying the meaning. Yet a further stage in this process may be noted. After the development of those grammatical forms which make definite statements possible, we do not at first find them used to express anything beyond statements of a simple kind. A single subject with a single predicate, accompanied by but few qualifying terms, are usually all. If we compare, for instance, the Hebrew scriptures with writings of modern times, a marked difference of aggregation among the groups of words, is visible. In the number of subordinate propositions which accompany the principal one; in the various complements to subjects and predicates; and in the numerous qualifying clauses — all of them united into one complex whole — many sentences in modern compositions exhibit a degree of integration not to be found in ancient ones.

§113. The history of Science presents facts of the same meaning at every step. Indeed the integration of groups of like entities and like relations, constitutes the most conspicuous part of scientific progress. A glance at the classificatory sciences, shows that the confused incoherent aggregations which the vulgar make of natural objects, are gradually rendered complete and compact, and bound up into groups within groups. While, instead of considering all marine creatures as fish, shell-fish, and jellyfish, Zoology establishes among them subdivisions under the heads Vertebrata, Annulosa, Mollusca, Coelenterata, etc.; and while, in place of the wide and vague assemblage popularly described as "creeping things," it makes the specific classes Annelida, Myiiapoda, Insecta, Arachnida; it simultaneously gives to these an increasing consolidation. The several species, genera, and orders of which each consists, are arranged according to their affinities and tied together under common definitions; at the same time that, by extended observation and rigorous criticism, the previously unknown and undetermined forms are integrated with their respective congeners. Nor is the process less clearly displayed in those sciences which have for their subject-matter, not classified objects but classified relations. Under one of its chief aspects, scientific advance is the advance of generalization; and generalizing is uniting into groups all like co-existences and sequences among phenomena. The colligation of many concrete relations into a generalization of the lowest order, exemplifies this process in its simplest form; and it is again exemplified in a more complex form by the colligation of these lowest generalizations into higher ones, and these into still higher ones. Year by year connexions are established among orders of phenomena that appear unallied; and these connexions, multiplying and strengthening, gradually bring the seemingly unallied orders under a common bond. When, for example, Humboldt quotes the observation of the Swiss — "it is going to rain because we hear the murmur of the torrents nearer," — when he recognizes the kinship between this and an observation of his own, that the cataracts of the Orinoco are heard at a greater distance by night than by day — when he notes the analogy between these facts and the fact that the unusual visibility of remote objects is also an indication of coming rain — and when he points out that the common cause of these variations is the smaller hindrance offered to the passage of both light and sound, by media which are comparatively homogeneous, either in temperature or hygrometric state; he helps in bringing under one generalization certain traits of light and certain traits of sound. Experiments having shown that light and sound conform to like laws of reflection and refraction, the conclusion that they are both produced by undulations —though undulations of unlike kinds — gains probability: there is an incipient integration of two classes of facts between which no connexion was suspected in times past. A still more decided integration has been of late taking place between the once independent sub-sciences of Electricity, Magnetism, and Light.

The process will manifestly be carried much further. Such propositions as those set forth in preceding chapters, on "The Persistence of Force," "The Transformation and Equivalence of Forces," "The Direction of Motion," and "The Rhythm of Motion," unite within single bonds phenomena belonging to all orders of existences. And if there is such a thing as that which we here understand by Philosophy, there must eventually be reached a universal integration.

§114. Nor do the industrial and aesthetic Arts fail to supply us with equally conclusive evidence. The progress from small and simple tools, to complex and large machines, is a progress in integration. Among what are classed as the mechanical powers, the advance from the lever to the wheel-and-axle is an advance from a simple agent to an agent made up of several simple ones. On comparing the wheel-and-axle, or any of the mechanical appliances used in early times with those used now, we see that in each of our machines several of the primitive machines are united. A modern apparatus for spinning or weaving, for making stockings or lace, contains not simply a lever, an inclined plane, a screw, a wheel-and-axle, joined together, but several of each — all made into a whole. Again, in early ages, when horsepower and man-power were alone employed, the motive agent was not bound up with the tool moved; but the two have now become in many cases joined together. The firebox and boiler of a locomotive are combined with the machinery which the steam works. A much more extensive integration is seen in every factory. Here numerous complicated machines are all connected by driving shafts with the same steam-engine — all united with it into one vast apparatus.

Contrast the mural decorations of the Egyptians and Assyrians with modern historical paintings, and there is manifest an advance in unity of composition — in the subordination of the parts to the whole. One of these ancient frescoes is made up of figures which vary but little in conspicuousness: there are no gradations of light and shade. The same trait may be noted in the tapestries of medieval days. Representing perhaps a hunting scene, one of these contains men, horses, dogs, beasts, birds, trees, and flowers, miscellaneously dispersed: the living objects being variously occupied, and mostly with no apparent consciousness of one another's proximity. But in paintings since produced, faulty as many of them are in this respect, there is always some co-ordination — an arrangement of attitudes, expressions, lights, and colours, such as to combine the parts into a single scene; and the success with which unity of effect is educed from variety of components, is a chief test of merit.

In music, progressive integration is displayed in more numerous ways. The simple cadence embracing but a few notes, which in the chants of savages is monotonously repeated, becomes, among civilized races, a long series of different musical phrases combined into one whole; and so complete is the integration that the melody cannot be broken off in the middle, nor shorn of its final note, without giving us a painful sense of incompleteness. When to the air, a bass, a tenor, and an alto are added; and when to the different voice-parts there is joined an accompaniment; we see integrations of another order which grow gradually more elaborate. And the process is carried a stage higher when these complex solos, concerted pieces, choruses, and orchestral effects, are combined into the vast ensemble of an oratorio or a musical drama.

Once more the Arts of literary delineation, narrative and dramatic, furnish us with illustrations. The tales of primitive times, like those with which the storytellers of the East still amuse their listeners, are made up of successive occurrences, mostly unnatural, that have no natural connexions: they are but so many separate adventures put together without necessary sequence. But in a good modern work of imagination, the events are the proper products of the characters living under given conditions; and cannot at will be changed in their order or kind, without injuring or destroying the general effect. Further, the characters themselves, which in early fictions play their respective parts without showing how their minds are modified by one another or by the events, are now presented to us as held together by complex moral relations, and as acting and reacting on one another's natures.

§115. Evolution, then, under its primary aspect, is a change from a less coherent form to a more coherent form, consequent on the dissipation of motion and integration of matter. This is the universal process through which sensible existences, individually and as a whole, pass during the ascending halves of their histories. This proves to be a character displayed in those earliest changes which the visible Universe is supposed to have undergone, and in those latest changes which we trace in societies and the products of social life. And, throughout, the unification proceeds in several ways simultaneously.

Alike during the evolution of the Solar System, of a planet, of an organism, of a nation, there is progressive aggregation. This may be shown by the increasing density of the matter already contained in it; or by the drawing into it of matter that was before separate: or by both. But in any case it implies a loss of relative motion. At the same time, the parts into which the mass has divided, severally consolidate in like manner. We see this in that formation of planets and satellites which has gone on along with the progressive concentration of the nebula that originated the Solar System; we see it in that growth of separate organs which advances,pari passu, with the growth of each organism; we see it in that rise of special industrial centres and special masses of population, which is associated with the development of each society. Always more or less of local integration accompanies the general integration. And then, beyond the increased closeness of juxtaposition among the components of the whole, and among the components of each part, there is increase of combination, producing mutual dependence of them. Dimly foreshadowed as this mutual dependence is among inorganic existences, both celestial and terrestrial, it becomes distinct among organic and super-organic existences. From the lowest living forms upwards, the degree of development is marked by the degree in which the several parts constitute a co-operative assemblage — are integrated into a group of organs that live for and by one another. The like contrast between undeveloped and developed societies is conspicuous: there is an ever-increasing coordination of parts. And the same thing holds true of social products, as, for instance, of Science; which has become highly integrated not only in the sense that each division is made up of dependent propositions, but in the sense that the several divisions cannot carry on their respective investigations without aid from one another.

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