The Riddle of the Universe at the close of the nineteenth century

by Ernst Haeckel

IV. This universal movement of substance in space takes the form of an eternal cycle or of a periodical process of evolution.

V. The phases of this evolution consist in a periodic change of consistency, of which the first outcome is the primary division into mass and ether—the ergonomy of ponderable and imponderable matter.

VI. This division is effected by a progressive condensation of matter as the formation of countless infinitesimal “centres of condensation,” in which the inherent primitive properties of substance—feeling and inclination—are the active causes.

VII. While minute and then larger bodies are being formed by this pyknotic process in one part of space, and the intermediate ether increases its strain, the opposite process—the destruction of cosmic bodies by collision—is taking place in another quarter.

VIII. The immense quantity of heat which is generated in this mechanical process of the collision of swiftly moving bodies represents the new kinetic energy which effects the movement of the resultant nebulæ and the construction of new rotating bodies. The eternal drama begins afresh. Even our mother earth, which was formed of part of the gyrating solar system millions of ages ago, will grow cold and lifeless after the lapse of further millions, and, gradually narrowing its orbit, will fall eventually into the sun.

It seems to me that these modern discoveries as to the periodic decay and re-birth of cosmic bodies, which we owe to the most recent advance of physics and astronomy, associated with the law of substance, are especially important in giving us a clear insight into the universal cosmic process of evolution. In their light our earth shrinks into the slender proportions of a “mote in the sunbeam,” of which unnumbered millions chase each other through the vast depths of space. Our own “human nature,” which exalted itself into an image of God in its anthropistic illusion, sinks to the level of a placental mammal, which has no more value for the universe at large than the ant, the fly of a summer’s day, the microscopic infusorium, or the smallest bacillus. Humanity is but a transitory phase of the evolution of an eternal substance, a particular phenomenal form of matter and energy, the true proportion of which we soon perceive when we set it on the background of infinite space and eternal time.

Since Kant explained space and time to be merely “forms of perception”—space the form of external, time of internal, sensitivity—there has been a keen controversy, which still continues, over this important problem. A large section of modern metaphysicians have persuaded themselves that this “critical fact” possesses a great importance as the starting-point of “a purely idealist theory of knowledge,” and that, consequently, the natural opinion of the ordinary healthy mind as to the reality of time and space is swept aside. This narrow and ultra-idealist conception of time and space has become a prolific source of error. It overlooks the fact that Kant only touched one side of the problem, the subjective side, in that theory, and recognized the equal validity of its objective side. “Time and space,” he said, “have empirical reality, but transcendental ideality.” Our modern monism is quite compatible with this thesis of Kant’s, but not with the one-sided exaggeration of the subjective aspect of the problem; the latter leads logically to the absurd idealism that culminates in Berkeley’s thesis, “Bodies are but ideas; their essence is in their perception.” The thesis should be read thus: “Bodies are only ideas for my personal consciousness; their existence is just as real as that of my organs of thought, the ganglionic cells in the gray bed of my brain, which receive the impress of bodies on my sense-organs and form those ideas by association of the impressions.” It is just as easy to doubt or to deny the reality of my own consciousness as to doubt that of time and space. In the delirium of fever, in hallucinations, in dreams, and in double-consciousness, I take ideas to be true which are merely fancies. I mistake my own personality for another (vide [p. 185]); Descartes’ famous Cogito ergo sum applies no longer. On the other hand, the reality of time and space is now fully established by that expansion of our philosophy which we owe to the law of substance and to our monistic cosmogony. When we have happily got rid of the untenable idea of “empty space,” there remains as the infinite “space-filling”-medium matter, in its two forms of ether and mass. So also we find a “time-filling” event in the eternal movement, or genetic energy, which reveals itself in the uninterrupted evolution of substance, in the perpetuum mobile of the universe.

As a body which has been set in motion continues to move as long as no external agency interferes with it, the idea was conceived long ago of constructing an apparatus which should illustrate perpetual motion. The fact was overlooked that every movement meets with external impediments and gradually ceases, unless a new impetus is given to it from without and a new force is introduced to counteract the impediments. Thus, for instance, a pendulum would swing backward and forward for an eternity at the same speed if the resistance of the atmosphere and the friction at the point it hangs from did not gradually deprive it of the mechanical kinetic energy of its motion and convert it into heat. We have to furnish it with fresh mechanical energy by a spring (or, as in the pendulum-clock, by the drag of a weight). Hence it is impossible to construct a machine that would produce, without external aid, a surplus of energy by which it could keep itself going. Every attempt to make such a perpetuum mobile must necessarily fail; the discovery of the law of substance showed, in addition, the theoretical impossibility of it.

The case is different, however, when we turn to the world at large, the boundless universe that is in eternal movement. The infinite matter, which fills it objectively, is what we call space in our subjective impression of it; time is our subjective conception of its eternal movement, which is, objectively, a periodic, cyclic evolution. These two “forms of perception” teach us the infinity and eternity of the universe. That is, moreover, equal to saying that the universe itself is a perpetuum mobile. This infinite and eternal “machine of the universe” sustains itself in eternal and uninterrupted movement, because every impediment is compensated by an “equivalence of energy,” and the unlimited sum of kinetic and potential energy remains always the same. The law of the persistence of force proves also that the idea of a perpetuum mobile is just as applicable to, and as significant for, the cosmos as a whole as it is impossible for the isolated action of any part of it. Hence the theory of entropy is likewise untenable.

The able founder of the mechanical theory of heat (1850), Clausius, embodied the momentous contents of this important theory in two theses. The first runs: “The energy of the universe is constant”—that is one-half of our law of substance, the principle of energy (vide [p. 230]). The second thesis is: “The energy of the universe tends towards a maximum.” In my opinion this second assertion is just as erroneous as the first is true. In the theory of Clausius the entire energy of the universe is of two kinds, one of which (heat of the higher degree, mechanical, electrical, chemical energy, etc.) is partly convertible into work, but the other is not; the latter energy, already converted into heat and distributed in the cooler masses, is irrevocably lost as far as any further work is concerned. Clausius calls this unconsumed energy, which is no longer available for mechanical work, entropy (that is, force that is directed inward); it is continually increasing at the cost of the other half. As, therefore, the mechanical energy of the universe is daily being transformed into heat, and this cannot be reconverted into mechanical force, the sum of heat and energy in the universe must continually tend to be reduced and dissipated. All difference of temperature must ultimately disappear, and the completely latent heat must be equally distributed through one inert mass of motionless matter. All organic life and movement must cease when this maximum of entropy has been reached. That would be a real “end of the world.”