Pioneers of Evolution from Thales to Huxley / With an Intermediate Chapter on the Causes of Arrest of the Movement

by Edward Clodd

2. Herbert Spencer.

Contact with many “sorts and conditions of men” brings home the need of ceaselessly dinning into their ears the fact that Darwin’s theory deals only with the evolution of plants and animals from a common ancestry. It is not concerned with the origin of life itself, nor with those conditions preceding life which are covered by the general term, Inorganic Evolution. Therefore, it forms but a very small part of the general theory of the origin of the earth and other bodies, “as the sand by the seashore innumerable,” that fill the infinite spaces.

We have seen that speculation about the universe had its rise in Ionia. After centuries of discouragement, prohibition, and, sometimes, actual persecution, it was revived, to advance, without further serious arrest, some three hundred years ago. A survey of the history of philosophies of the origin of the cosmos from the time of the renascence of inquiry, shows that the great Immanuel Kant has not had his due. As remarked already, he appears to have been the first to put into shape what is known as the nebular theory. In his General Natural History and Theory of the Celestial Bodies; or an Attempt to Account for the Constitution and the Mechanical Origin of the Universe upon Newtonian Principles, published in 1775, he “pictures to himself the universe as once an infinite expansion of formless and diffused matter. At one point of this he supposes a single centre of attraction set up, and shows how this must result in the development of a prodigious central body, surrounded by systems of solar and planetary worlds in all stages of development. In vivid language he depicts the great world-maelstrom, widening the margins of its prodigious eddy in the slow progress of millions of ages, gradually reclaiming more and more of the molecular waste, and converting chaos into cosmos. But what is gained at the margin is lost in the centre; the attractions of the central systems bring their constituents together, which then, by the heat evolved, are converted once more into molecular chaos. Thus the worlds that are lie between the ruins of the worlds that have been and the chaotic materials of the worlds that shall be; and in spite of all waste and destruction, Cosmos is extending his borders at the expense of Chaos.”

Kant’s speculations were confirmed by the celebrated mathematician, Laplace. He showed that the “rings” rotate in the same direction as the central body from which they were cast off; sun, planets, and moons (those of Uranus excepted) moving in a common direction, and almost in the same plane. The probability that these harmonious movements are the effects of like causes he calculated as 200,000 billions to one.

The observations of the famous astronomer, Sir William Herschel, which resulted in the discovery of binary or double stars, of star-clusters, and cloud-like nebulæ (as that term implies) were further confirmations of Kant’s theory. And such modifications in this as have been made by subsequent advance in knowledge, notably by the doctrine of the Conservation of Energy (the hypothesis of Kant and Laplace being based on gravitation alone), affect not the general theory of the origin of the heavenly bodies from seemingly formless, unstable, and highly-diffused matter. The assumption of primitive unstableness and unlikeness squares with the unequal distribution of matter; with the movements of its masses in different directions, and at different rates; and with the ceaseless redistribution of matter and motion. For all changes of states are due to the rearrangement of the atoms of which matter is made up, resulting in the evolution of the seeming like into the actual unlike; of the simple into the more and more complex, till—speaking of the only planet of whose life-history we can have knowledge—with the cooling of the earth to a temperature permitting of the evolution of living matter, the highest complexity is reached in the infinitely diverse forms of plants and animals. Therefore, as our knowledge of matter is limited to the changes of which we assume it to be the vehicle, it would seem that science reduces the Universe to the intelligible concept of Motion.

Since the great discovery by Kirchoff, in 1859, of the meaning of the dark lines that cross the refracted sun-rays, the spectroscope has come as powerful evidence in support of the nebular theory, while the photographic plate is a scarcely less important witness. The one has demonstrated that many nebulæ, once thought to be star-clusters, are masses of glowing hydrogen and nitrogen gases; that, to quote the striking communication made by the highest authority on the subject, Dr. Huggins, in his Presidential Address to the British Association, 1891, “in the part of the heavens within our ken, the stars still in the early and middle stages of evolution exceed greatly in number those which appear to be in an advanced condition of condensation.” The other, recording infallible vibrations on a sensitive plate, and securing accurate registration of the impressions, reveals, as in Dr. Roberts’s grand photograph of the nebula in Andromeda, a central mass round which are distinct rings of luminous matter, these being separated from the main body by dark rifts or spaces. To quote Dr. Huggins once more, “We seem to have presented to us some stage of cosmical Evolution on a gigantic scale.”

The great fact that lies at the back of all these confirmations of the nebular theory is the fundamental identity of the stuff of which the universe is made; a fact which entered into the prevision of the Ionian cosmologists. Dr. Huggins says that “if the whole earth were heated to the temperature of the sun, its spectrum would resemble very closely the solar spectrum.”

In referring to this, there may be carrying of “owls to Athens,” but that re-statements may sometimes be needful has illustration in Lord Salisbury’s Presidential Address to the British Association, 1894, wherein the assumed absence of oxygen and nitrogen in the sun’s spectrum is adduced as an argument against the theory of the common origin of the bodies of the solar system. Speaking of the predominant proportion of oxygen in the solid and liquid substances of the earth, and of the predominance of nitrogen in our atmosphere, his lordship asked, “if the earth be a detached bit whisked off the mass of the sun, as cosmogonists love to tell us, how comes it that, in leaving the sun, we cleaned him out so completely of his nitrogen and oxygen that not a trace of these gases remains behind to be discovered even by the searching vision of the spectroscope?” If Lord Salisbury had consulted Dr. Huggins, or some foreign astronomer of equal rank, as Dunér or Scheiner, he would not have put a question exposing his ignorance, and unmasking his prejudice. These authorities would have told him that when a mixture of the incandescent vapours of the metals and metalloids (or non-metallic elementary substances, to which class both oxygen and nitrogen belong), or their compounds, is examined with the spectroscope, the spectra of the metalloids always yield before that of the metals. Hence the absence of the lines of oxygen and other metalloids, carbon and silicon excepted, among the vast crowd of lines in the solar spectrum. Then, too, in extreme states of rarefaction of the sun’s absorbing layer, the absorption of the oxygen is too small to be sensible to us.

“While the genesis of the Solar System, and of countless other systems like it, is thus rendered comprehensible, the ultimate mystery continues as great as ever. The problem of existence is not solved: it is simply removed further back. The Nebular Hypothesis throws no light on the origin of diffused matter; and diffused matter as much needs accounting for as concrete matter. The genesis of an atom is not easier to conceive than the genesis of a planet. Nay, indeed, so far from making the universe a less mystery than before, it makes it a greater mystery. Creation by manufacture is a much lower thing than creation by evolution. A man can put together a machine; but he cannot make a machine develop itself. The ingenious artisan, able as some have been so far to imitate vitality as to produce a mechanical pianoforte player, may in some sort conceive how, by greater skill, a complete man might be artificially produced; but he is unable to conceive how such a complex organism gradually arises out of a minute structureless germ. That our harmonious universe once existed potentially as formless diffuse matter, and has slowly grown into its present organized state, is a far more astonishing fact than would have been its formation after the artificial method vulgarly supposed. Those who hold it legitimate to argue from phenomena to noumena, may rightly contend that the Nebular Hypothesis implies a First Cause as much transcending ‘the mechanical God of Paley’ as does the fetish of the savage.”