The Online Library of Liberty

A project of Liberty Fund, Inc.

• Part I.: The Unknowable.
• Chapter I.: Religion and Science.
• Chapter II.: Ultimate Religious Ideas.
• Chapter III.: Ultimate Scientific Ideas.
• Chapter IV.: The Relativity of All Knowledge.
• Chapter V.: The Reconciliation.
• Part II.: The Knowable.
• Chapter I.: Philosophy Defined.
• Chapter II.: The Data of Philosophy.
• Chapter III.: Space, Time, Matter, Motion, and Force.
• Chapter IV.: The Indestructibility of Matter.
• Chapter V.: The Continuity of Motion.
• Chapter VI.: The Persistence of Force. ∗
• Chapter VII.: The Persistence of Relations Among Forces.
• Chapter VIII.: The Transformation and Equivalence of Forces.
• Chapter IX.: The Direction of Motion.
• Chapter X.: The Rhythm of Motion.
• Chapter XI.: Recapitulation, Criticism, and Recommencement.
• Chapter XII.: Evolution and Dissolution.
• Chapter XIII.: Simple and Compound Evolution.
• Chapter XIV.: The Law of Evolution.
• Chapter XV.: The Law of Evolution Continued.
• Chapter XVI.: The Law of Evolution Continued.
• Chapter XVII.: The Law of Evolution Concluded.
• Chapter XVIII.: The Interpretation of Evolution.
• Chapter XIX.: The Instability of the Homogeneous. ∗
• Chapter XX.: The Multiplication of Effects.
• Chapter XXI.: Segregation.
• Chapter XXII.: Equilibration.
• Chapter XXIII.: Dissolution.
• Chapter XXIV.: Summary and Conclusion.

CHAPTER XXIII.

DISSOLUTION.

§ 177. When, in Chapter XII., we glanced at the cycle of changes through which every existence passes, in its progress from the imperceptible to the perceptible and again from the perceptible to the imperceptible—when these opposite re-distributions of matter and motion were severally distinguished as Evolution and Dissolution; the natures of the two, and the conditions under which they respectively occur, were specified in general terms. Since then, we have contemplated the phenomena of Evolution in detail; and have followed them out to those states of equilibrium in which they all end. To complete the argument we must now contemplate, somewhat more in detail than before, the complementary phenomena of Dissolution. Not, indeed, that we need dwell long on Dissolution, which has none of those various and interesting aspects which Evolution presents; but something more must be said than has yet been said.

It was shown that neither of these two antagonist processes ever goes on absolutely unqualified by the other; and that a change towards either is a differential result of the conflict between them. An evolving aggregate, while on the average losing motion and integrating, is always, in one way or other, receiving some motion and to that extent disintegrating; and after the integrative changes have ceased to predominate, the reception of motion, though perpetually checked by its dissipation, constantly tends to produce a reverse transformation, and eventually does produce it. When Evolution has run its course—when the aggregate has at length parted with its excess of motion, and habitually receives as much from its environment as it habitually loses—when it has reached that equilibrium in which its changes end; it thereafter remains subject to all actions in its environment which may increase the quantity of motion it contains, and which in the lapse of time are sure, either slowly or suddenly, to give its parts such excess of motion as will cause disintegration. According as its equilibrium is a very unstable or a very stable one, its dissolution may come quickly or may be indefinitely delayed—may occur in a few days or may be postponed for millions of years. But exposed as it is to the contingencies not simply of its immediate neighbourhood but of a Universe everywhere in motion, the period must at last come when, either alone or in company with surrounding aggregates, it has its parts dispersed.

The process of dissolution so caused, we have here to look at as it takes place in aggregates of different orders. The course of change being the reverse of that hitherto traced, we may properly take the illustrations of it in the reverse order—beginning with the most complex and ending with the most simple.

§ 178. Regarding the evolution of a society as at once an increase in the number of individuals integrated into a corporate body, an increase in the masses and varieties of the parts into which this corporate body divides as well as of the actions called their functions, and an increase in the degree of combination among these masses and their functions; we shall see that social dissolution conforms to the general law in being, materially considered, a disintegration, and, dynamically considered, a decrease in the movements of wholes and an increase in the movements of parts; while it further conforms to the general law in being caused by an excess of motion in some way or other received from without.

It is obvious that the social dissolution which follows the aggression of another nation, and which, as history shows us, is apt to occur when social evolution has ended and decay has begun, is, under its broadest aspect, the incidence of a new external motion; and when, as sometimes happens, the conquered society is dispersed, its dissolution is literally a cessation of those corporate movements which the society, both in its army and in its industrial bodies, presented, and a lapse into individual or uncombined movements—the motion of units replaces the motion of masses.

It cannot be questioned, either, that when plague or famine at home, or a revolution abroad, gives to any society an unusual shock that causes disorder, or incipient dissolution, there results a decrease of integrated movements and an increase of disintegrated movements. As the disorder progresses, the political actions previously combined under one government become uncombined: there arise the antagonistic actions of riot or revolt. Simultaneously, the industrial and commercial processes that were co-ordinated throughout the whole body politic, are broken up; and only the local, or small, trading transactions continue. And each further disorganizing change diminishes the joint operations by which men satisfy their wants, and leaves them to satisfy their wants, so far as they can, by separate operations. Of the way in which such disintegrations are liable to be set up in a society that has evolved to the limit of its type, and reached a state of moving equilibrium, a good illustration is furnished by Japan. The finished fabric into which its people had organized themselves, maintained an almost constant state so long as it was preserved from fresh external forces. But as soon as it received an impact from European civilization, partly by armed aggression, partly by commercial impulse, partly by the influence of ideas, this fabric began to fall to pieces. There is now in progress a political dissolution. Probably a political re-organization will follow; but, be this as it may, the change thus far produced by an outer action is a change towards dissolution—a change from integrated motions to disintegrated motions.

Even where a society that has developed into the highest form permitted by the characters of its units, begins thereafter to dwindle and decay, the progressive dissolution is still essentially of the same nature. Decline of numbers is, in such case, brought about partly by emigration; for a society having the fixed structure in which evolution ends, is necessarily one that will not yield and modify under pressure of population: so long as its structure will yield and modify, it is still evolving. Hence the surplus population continually produced, not held together by an organization that adapts itself to an augmenting number, is continually dispersed: the influences brought to bear on the citizens by other societies, cause their detachment, and there is an increase in the uncombined motions of units instead of an increase of combined motions. Gradually as rigidity becomes greater, and the society becomes still less capable of being re-moulded into the form required for successful competition with growing and more plastic societies, the number of citizens who can live within its unyielding framework becomes positively smaller. Hence it dwindles both through continued emigration and through the diminished multiplication that follows innutrition. And this further dwindling or dissolution, caused by the number of those who die becoming greater than the number of those who survive long enough to rear offspring, is similarly a decrease in the total quantity of combined motion and an increase in the quantity of uncombined motion—as we shall presently see when we come to deal with individual dissolution.

Considering, then, that social aggregates differ so much from aggregates of other kinds, formed as they are of units held together loosely and indirectly, in such variable ways by such complex forces, the process of dissolution among them conforms to the general law quite as clearly as could be expected.

§ 179. When from these super-organic aggregates we descend to organic aggregates, the truth that Dissolution is a disintegration of matter, caused by the reception of additional motion from without, becomes easily demonstrable. We will look first at the transformation and afterwards at its cause.

Death, or that final equilibration which precedes dissolution, is the bringing to a close of all those conspicuous integrated motions that arose during evolution. The impulsions of the body from place to place first cease; presently the limbs cannot be stirred; later still the respiratory actions stop; finally the heart becomes stationary, and, with it, the circulating fluids. That is, the transformation of molecular motion into the motion of masses, comes to an end; and each of these motions of masses, as it ends, disappears into molecular motions. What next takes place? We cannot say that there is any further transformation of sensible movements into insensible movements; for sensible movements no longer exist. Nevertheless, the process of decay involves an increase of insensible movements; since these are far greater in the gases generated by decomposition, than they are in the fluid-solid matters out of which the gases arise. Each of the complex chemical units composing an organic body, possesses a rhythmic motion in which its many component units jointly partake. When decomposition breaks up these complex molecules, and their constituents assume gaseous forms, there is, besides that increase of motion implied by the diffusion, a resolution of such motions as the aggregate molecules possessed, into motions of their constituent molecules. So that in organic dissolution we have, first, an end put to that transformation of the motion of units into the motion of aggregates, which constitutes evolution, dynamically considered; and we have also, though in a subtler sense, a transformation of the motion of aggregates into the motion of units. Still it is not thus shown that organic dissolution fully answers to the general definition of dissolution—the absorption of motion and concomitant disintegration of matter. The disintegration of matter is, indeed, conspicuous enough; but the absorption of motion is not conspicuous. True, the fact that motion has been absorbed may be inferred from the fact that the particles previously integrated into a solid mass, occupying a small space, have most of them moved away from one another and now occupy a great space; for the motion implied by this transposition must have been obtained from somewhere. But its source is not obvious. A little search, however, will bring us to its derivation.

At a temperature below the freezing point of water, decomposition of organic matter does not take place—the integrated motions of the highly integrated molecules are not resolved into the disintegrated motions of their component molecules. Dead bodies kept at this temperature for an indefinitely long period, are prevented from decomposing for an indefinitely long period: witness the frozen carcases of Mammoths—Elephants of a species long ago extinct—that are found imbedded in the ice at the mouths of Siberian rivers; and which, though they have been there for many thousands of years, have flesh so fresh that when at length exposed, it is devoured by wolves. What now is the meaning of such exceptional preservations? A body kept below freezing point, is a body which receives very little heat by radiation or conduction; and the reception of but little heat is the reception of but little molecular motion. That is to say, in an environment which does not furnish it with molecular motion passing a certain amount, an organic body does not undergo dissolution. Confirmatory evidence is yielded by the variations in rate of dissolution which accompany variations of temperature. All know that in cool weather the organic substances used in our house-holds keep longer, as we say, than in hot weather. Equally certain, if less familiar, is the fact that in tropical climates decay proceeds much more rapidly than in temperate climates. Thus, in proportion as the molecular motion of surrounding matter is great, the dead organism receives an abundant supply of motion to replace the motion continually taken up by the dispersing molecules of the gases into which it is being disintegrated. The still quicker decompositions produced by exposure to artificially-raised temperatures, afford further proofs; as instance those which occur in cooking. The charred surfaces of parts that have been much heated, show us that the molecular motion absorbed has served to dissipate in gaseous forms all the elements but the carbon.

The nature and cause of Dissolution are thus clearly displayed by the aggregates which so clearly display the nature and cause of Evolution. One of these aggregates being composed of that peculiar matter to which a large quantity of constitutional motion gives great plasticity, and the ability to evolve into a highly compound form (§ 103); we see that after evolution has ceased, a very moderate amount of molecular motion, added to that already locked up in its peculiar matter, suffices to cause dissolution. Though at death there is reached a stable equilibrium among the sensible masses, or organs, which make up the body; yet, as the insensible units or molecules of which these organs consist are in unstable equilibrium, small incident forces suffice to overthrow them, and hence disintegration proceeds rapidly.

§ 180. Most inorganic aggregates, having arrived at dense forms in which comparatively little motion is retained, remain long without marked changes. Each has lost so much motion in passing from the disintegrated to the integrated state, that much motion must be given to it to cause resumption of the disintegrated state; and an immense time may elapse before there occur in the environment, changes great enough to communicate to it the requisite quantity of motion. We will look first at those exceptional inorganic aggregates which retain much motion, and therefore readily undergo dissolution.

Among these are the liquids and volatile solids which dissipate under ordinary conditions—water that evaporates, carbonate of ammonia that wastes away by the dispersion of its molecules. In all such cases motion is absorbed; and always the dissolution is rapid in proportion as the quantity of heat or motion which the aggregated mass receives from its environment is great. Next come the cases in which the molecules of a highly integrated or solid aggregate, are dispersed among the molecules of a less integrated or liquid aggregate; as in aqueous solutions. One evidence that this disintegration of matter has for its concomitant the absorption of motion, is that soluble substances dissolve the more quickly the hotter the water: supposing always that no elective affinity comes into play. Another and still more conclusive evidence is, that when crystals of a given temperature are placed in water of the same temperature, the process of solution is accompanied by a fall of temperature—often a very great one. Omitting instances in which some chemical action takes place between the salt and the water, it is a uniform law that the motion which disperses the molecules of the salt through the water, is at the expense of the molecular motion possessed by the water.

Masses of sediment accumulated into strata, afterwards compressed by many thousands of feet of superincumbent strata, and reduced in course of time to a solid state, may remain for millions of years unchanged; but in subsequent millions of years they are inevitably exposed to disintegrating actions. Raised along with other such masses into a continent, denuded and exposed to rain, frost, and the grinding actions of glaciers, they have their particles gradually separated, carried away, and widely dispersed. Or when, as otherwise happens, the encroaching sea reaches them, the undermined cliffs which they form fall from time to time, breaking into fragments of all sizes; the waves, rolling about the small pieces, and in storms turning over and knocking together the larger blocks, reduce them to boulders and pebbles, and at last to sand and mud. Even if portions of the disintegrated strata accumulate into shingle banks, which afterwards become solidified, the process of dissolution, arrested though it may be for some enormous geologic period, is finally resumed. As many a shore shows us, the conglomerate itself is sooner or later subject to the like processes; and its cemented masses of heterogeneous components, lying on the beach, are broken up and worn away by impact and attrition—that is, by communicated mechanical motion.

When not thus effected, the disintegration is effected by communicated molecular motion. The consolidated stratum, located in some area of subsidence, and brought down nearer and nearer to the regions occupied by molten matter, comes eventually to have its particles brought to a plastic state by heat, or finally melted down into liquid. Whatever may be its subsequent transformations, the transformation then exhibited by it is an absorption of motion and disintegration of matter.

Be it simple or compound, small or large, a crystal or a mountain chain, every inorganic aggregate on the Earth, thus, at some time or other, undergoes a reversal of those changes undergone during its evolution. Not that it usually passes back completely from the perceptible into the imperceptible; as organic aggregates do in great part, if not wholly. But still its disintegration and dispersion carry it some distance on the way towards the imperceptible; and there are reasons for thinking that its arrival there is but delayed. At a period immeasurably remote, every such inorganic aggregate, along with all undissipated remnants of organic aggregates, must be reduced to a state gaseous diffusion, and so complete the cycle of its of changes.

§ 181. For the Earth as a whole, when it has gone through the entire series of its ascending transformations, must remain, like all smaller aggregates, exposed to the contingencies of its environment; and in the course of those ceaseless changes in progress throughout a Universe of which all parts are in motion, must, at some period beyond the utmost stretch of imagination, be subject to forces sufficient to cause its complete disintegration. Let us glance at the forces competent to disintegrate it.

In his essay on “The Inter-action of Natural Forces,” Prof. Helmholtz states the thermal equivalent of the Earth’s movement through space, as calculated on the now received datum of Mr. Joule. “If our Earth,” he says, “were by a sudden shock brought to rest in her orbit,—which is not to be feared in the existing arrangement of our system—by such a shock a quantity of heat would be generated equal to that produced by the combustion of fourteen such Earths of solid coal. Making the most unfavourable assumption as to its capacity for heat, that is, placing it equal to that of water, the mass of the Earth would thereby be heated 11,200 degrees; it would therefore be quite fused, and for the most part reduced to vapour. If then the Earth, after having been thus brought to rest, should fall into the Sun, which of course would be the case, the quantity of heat developed by the shock would be 400 times greater.” Now though this calculation seems to be nothing to the purpose, since the Earth is not likely to be suddenly arrested in its orbit and not likely therefore suddenly to fall into the Sun; yet, as before pointed out (§ 171), there is a force at work which it is held must at last bring the Earth into the Sun. This force is the resistance of the ethereal medium. From ethereal resistance is inferred a retardation of all moving bodies in the Solar System—a retardation which certain astronomers contend even now shows its effects in the relative nearness to one another of the orbits of the older planets. If, then, retardation is going on, there must come a time, no matter how remote, when the slowly diminishing orbit of the Earth will end in the Sun; and though the quantity of molar motion to be then transformed into molecular motion, will not be so great as that which the calculation of Helmholtz supposes, it will be great enough to reduce the substance of the Earth to a gaseous state.

This dissolution of the Earth, and, at intervals, of every other planet, is not, however, a dissolution of the Solar System. Viewed in their ensemble, all the changes exhibited throughout the Solar System, are incidents accompanying the integration of the entire matter composing it: the local integration of which each planet is the scene, completing itself long before the general integration is complete. But each secondary mass having gone through its evolution and reached a state of equilibrium among its parts, thereafter continues in its extinct state, until by the still progressing general integration it is brought into the central mass. And though each such union of a secondary mass with the central mass, implying transformation of molar motion into molecular motion, causes partial diffusion of the total mass formed, and adds to the quantity of motion that has to be dispersed in the shape of light and heat; yet it does but postpone the period at which the total mass must become completely integrated, and its excess of contained motion radiated into space.

∗ § 182. Here we come to the question raised at the close of the last chapter—does Evolution as a whole, like Evolution in detail, advance towards complete quiescence? Is that motionless state called death, which ends Evolution in organic bodies, typical of the universal death in which Evolution at large must end? And have we thus to contemplate as the outcome of things, a boundless space holding here and there extinct suns, fated to remain for ever without further change.

To so speculative an inquiry, none but a speculative answer is to be expected. Such answer as may be ventured, must be taken less as a positive answer than as a demurrer to the conclusion that the proximate result must be the ultimate result. If, pushing to its extreme the argument that Evolution must come to a close in complete equilibrium or rest, the reader suggests that for aught which appears to the contrary, the Universal Death thus implied will continue indefinitely, it is legitimate to point out how, on carrying the argument still further, we are led to infer a subsequent Universal Life. Let us see what may be assigned as grounds for inferring this.

It has been already shown that all equilibration, so far as we can trace it, is relative. The dissipation of a body’s motion by communication of it to surrounding matter, solid, liquid, gaseous, and ethereal, brings the body to a fixed position in relation to the matter that abstracts its motion. But all its other motions continue. Further, this motion, the disappearance of which causes relative equilibration, is not lost but simply transferred. Whether it is directly transformed into insensible motion, as happens in the case of the Sun; or, whether, as in the sensible motions going on around us, it is directly transformed into smaller sensible motions, and these into still smaller, until they become insensible, matters not. In every instance the ultimate result is, that whatever motion of masses is lost, reappears as molecular motion pervading space. Thus the questions we have to consider, are—Whether after the completion of all the relative equilibrations which bring Evolution to a close, there remain any further equilibrations to be effected?—Whether there are any other motions of masses that must eventually be transformed into molecular motion?—And if there are such other motions, what must be the consequence when the molecular motion generated by their transformation, is added to that which already exists?

To the first of these questions the answer is, that there do remain motions which are undiminished by all the relative equilibrations we have considered; namely, the motions of translation possessed by those vast masses of matter called stars—remote suns that are probably, like our own, surrounded by circling groups of planets. The belief that the stars are fixed, has long since been abandoned: observation has proved many of them to have sensible proper motions. Moreover, it has been ascertained by measurement that in relation to the stars nearest to us, our own star travels at the rate of about half a million miles per day; and if, as is admitted to be not improbable, our own star is moving in the same direction with adjacent stars, its absolute velocity may be, and most likely is, immensely greater than this. Now no such changes as those taking place within the Solar System, even when carried to the extent of integrating the whole of its matter into one mass, and diffusing all its relative motions in an insensible form through space, can affect these sidereal motions. Hence, there appears no alternative but to infer that they must remain to be equilibrated by some subsequent process.

The next question that arises is—To what law do sidereal motions conform? And to this question Astronomy replies—the law of gravitation. The movements of binary stars have proved this. The periodic times of sundry binary stars have been calculated on the assumption that their revolutions are determined by a force like that which regulates the revolutions of planets and satellites; and the subsequent performances of their revolutions in the predicted periods, have verified the assumption. If, then, these remote bodies are centres of gravitation—if we infer that all other stars are centres of gravitation, as we may fairly do—and if we draw the unavoidable corollary, that the gravitative force which so conspicuously affects stars that are near one another, also affects remote stars; we must conclude that all the members of our Sidereal System gravitate, individually and collectively.

But if these widely-dispersed moving masses mutually gravitate, what must happen? There appears but one tenable answer. They cannot preserve their present arrangement: the irregular distribution of our Sidereal System being such as to render even a temporary moving equilibrium impossible. If the stars are centres of an attractive force that varies inversely as the square of the distance, there is no escape from the inference that the structure of our galaxy is undergoing change, and must continue to undergo change.

Thus, in the absence of tenable alternatives, we are brought to the positions:—1, that the stars are in motion;—2, that they move in conformity with the law of gravitation;—3, that, distributed as they are, they cannot move in conformity with the law of gravitation, without undergoing re-arrangement. If now we ask the nature of this re-arrangement, we find ourselves obliged to infer a progressive concentration. Stars at present dispersed, must become locally aggregated; existing aggregations (excepting, perhaps, the globular clusters) must grow more dense;and aggregations must coalesce with one another. That integration has been progressing throughout past eras, we found to be indicated by the structure of the heavens, in general and in detail; and of the extent to which it has in some places already gone, remarkable instances are furnished by the Magellanic clouds—two closely-packed agglomerations, not, indeed, of single stars only, but of single stars, of clusters regular and irregular, of nebulæ, and of diffused nebulosity. That these have been formed by mutual gravitation of parts once widely scattered, there is evidence in the barrenness of the surrounding celestial spaces: the nubecula minor, especially, being seated, as Humboldt says, in “a kind of starless desert.”

What must be the limit of such concentrations? The mutual attraction of two stars, when it so far predominates over other attractions as to cause approximation, almost certainly ends in the formation of a binary star; since the motions generated by other attractions prevent the two stars from moving in straight lines to their common centre of gravity. Between small clusters, too, having also certain proper motions as clusters, mutual attraction may lead, not to complete union, but to the formation of binary clusters. As the process continues, however, and the clusters become larger, they must move more directly towards each other: thus forming clusters of increasing density. While, therefore, during the earlier stages of concentration, the probabilities are immense against the actual contact of these mutually-gravitating masses; it is tolerably manifest that, as the concentration increases, collision must become probable, and ultimately certain. This is an inference not lacking the support of high authority. Sir John Herschel, treating of those numerous and variously-aggregated clusters of stars revealed by the telescope, and citing with apparent approval his father’s opinion, that the more diffused and irregular of these, are “globular clusters in a less advanced state of condensation;” subsequently remarks, that “among a crowd of solid bodies of whatever size, animated by independent and partially opposing impulses, motions opposite to each other must produce collision, destruction of velocity, and subsidence or near approach towards the centre of preponderant attraction; while those which conspire, or which remain outstanding after such conflicts, must ultimately give rise to circulation of a permanent character.” Now what is here alleged of these minor clusters, cannot be denied of larger clusters; and thus the above-inferred process of concentration, appears certain to bring about an increasingly-frequent integration of masses.

We have next to consider the consequences of the accompanying loss of velocity. The sensible motion which disappears cannot be destroyed, but must be transformed into insensible motion. What will be the effect of this insensible motion? Already we have seen that were the Earth arrested, dissipation of its substance would result. And if so relatively small a momentum as that acquired by the Earth in falling to the Sun, would be equivalent to a molecular motion sufficient to reduce the Earth to gases of extreme rarity; what must be the molecular motion generated by the mutually-arrested momenta of two stars, that have moved to their common centre of gravity through spaces immeasurably greater? There seems no alternative but to conclude, that it would be great enough to reduce the matter of the stars to an almost inconceivable tenuity—a tenuity like that which we ascribe to nebular matter. Such being the immediate effect, what would be the ulterior effect? Sir John Herschel, in the passage above quoted, describing the collisions that must arise in a concentrating group of stars, adds that those stars “which remain outstanding after such conflicts must ultimately give rise to circulation of a permanent character.” The problem, however, is here dealt with purely as a mechanical one: the assumption being that the mutually-arrested masses will continue as masses—an assumption to which no objection appeared at the time when Sir John Herschel wrote this passage; since the correlation of forces was not then recognized. But obliged as we now are to conclude, that stars moving at the high velocities acquired during concentration, will, by mutual arrest, be dissipated into gases, the problem becomes different; and a different inference seems unavoidable. For the diffused matter produced by such conflicts must form a resisting medium, occupying that central region of the cluster through which its members from time to time pass in describing their orbits—a resisting medium which they cannot move through without having their velocities diminished. Every additional collision, by augmenting this resisting medium, and making the losses of velocity greater, must aid in preventing the establishment of that equilibrium which would else arise; and so must conspire to produce more frequent collisions. And the nebulous matter thus formed, presently enveloping the whole cluster, must, by continuing to shorten the gyrations of the moving masses, entail an increasingly active integration and reactive disintegration of them; until they are all dissipated. Whether this process completes itself independently in different parts of our Sidereal System; or whether it completes itself only by aggregating the whole matter of our Sidereal System; or whether, as seems not unlikely, local integrations and disintegrations run their courses while the general integration is going on; are questions that need not be discussed. In any case the conclusion to be drawn is, that the integration must continue until the conditions which bring about disintegration are reached; and that there must then ensure a diffusion that undoes the preceding concentration. This, indeed, is the conclusion which presents itself as a deduction from the persistence of force. If stars concentrating to a common centre of gravity, eventually reach it, then the quantities of motion they have acquired must suffice to carry them away again to those remote regions whence they started. And since, by the conditions of the case, they cannot return to these remote regions in the shape of concrete masses, they must return in the shape of diffused masses. Action and reaction being equal and opposite, the momentum producing dispersion, must be as great as the momentum acquired by aggregation; and being spread over the same quantity of matter, must cause an equivalent distribution through space, whatever be the form of the matter. One condition, however, essential to the literal fulfilment of this result, must be specified; namely, that the quantity of molecular motion radiated into space by each star in the course of its formation from diffused matter, shall either not escape from our Sidereal System or shall be compensated by an equal quantity of molecular motion radiated from other parts of space into our Sidereal System. In other words, if we set out with that amount of molecular motion implied by the existence of the matter of our Sidereal System in a nebulous form; then it follows from the persistence of force, that if this matter undergoes the re-distribution constituting Evolution, the quantity of molecular motion given out during the integration of each mass, plus the quantity of molecular motion given out during the integration of all the masses, must suffice again to reduce it to the same nebulous form.

Here, indeed, we arrive at a barrier to our reasonings; since we cannot know whether this condition is or is not fulfilled. If the ether which fills the interspaces of our Sidereal System has a limit somewhere beyond the outermost stars, then it is inferrable that motion is not lost by radiation beyond this limit; and if so, the original degree of diffusion may be resumed. Or supposing the ethereal medium to have no such limit, yet, on the hypothesis of an unlimited space, containing, at certain intervals, Sidereal Systems like our own, it may be that the quantity of molecular motion radiated into the region occupied by our Sidereal Systems, is equal to that which our Sidereal Systems radiates; in which case the quantity of motion possessed by it, remaining undiminished, it may continue during unlimited time its alternate concentrations and diffusions. But if, on the other hand, throughout boundless space filled with ether, there exist no other Sidereal Systems subject to like changes, or if such other Sidereal Systems exist at more than a certain average distance from one another; then it seems an unavoidable conclusion that the quantity of motion possessed, must diminish by radiation; and that so, on each successive resumption of the nebulous form, the matter of our Sidereal Systems will occupy a less space; until it reaches either a state in which its concentrations and diffusions are relatively small, or a state of complete aggregation and rest. Since, however, we have no evidence showing the existence or non-existence of Sidereal Systems throughout remote space; and since, even had we such evidence, a legitimate conclusion could not be drawn from premises of which one element (unlimited space) is inconceivable; we must be for ever without answer to this transcendent question.

But confining ourselves to the proximate and not necessarily insoluble question, we find reason for thinking that after the completion of those various equilibrations which bring to a close all the forms of Evolution we have contemplated, there must continue an equilibration of a far wider kind. When that integration everywhere in progress throughout our Solar System has reached its climax, there will remain to be effected the immeasureably greater integration of our Solar System, with other such systems. There must then re-appear in molecular motion what is lost in the motion of masses; and the inevitable transformation of this motion of masses into molecular motion, cannot take place without reducing the masses to a nebulous form.

§ 183. Thus we are led to the conclusion that the entire process of things, as displayed in the aggregate of the visible Universe, is analogous to the entire process of things as displayed in the smallest aggregates.

Motion as well as Matter being fixed in quantity, it would seem that the change in the distribution of Matter which Motion effects, coming to a limit in whichever direction it is carried, the indestructible Motion thereupon necessitates a reverse distribution. Apparently, the universally-co-existent forces of attraction and repulsion, which, as we have seen, necessitate rhythm in all minor changes throughout the Universe, also necessitate rhythm in the totality of its changes—produce now an immeasureable period during which the attractive forces predominating, cause universal concentration, and then an immeasureable period during which the repulsive forces predominating, cause universal diffusion—alternate eras of Evolution and Dissolution. And thus there is suggested the conception of a past during which there have been successive Evolutions analogous to that which is now going on; and a future during which successive other such Evolutions may go on—ever the same in principle but never the same in concrete result.

[∗]Though this chapter is new, this section, and the one following it, are not new. In the first edition they were included in the final section of the foregoing chapter. While substantially the same as before, the argument has been in some places abbreviated and in other places enforced by additional matter.