Читать книгу The Coming of Evolution - John W. Judd - Страница 9

Table of Contents

We have seen in the preceding chapter that, with respect to the origin of plants and animals—including man himself—two very distinct lines of speculation have arisen; these two lines of thought may be expressed by the terms 'manufacture'—literally making by hand, and 'development' or 'evolution,'—a gradual unfolding from simpler to more complex forms. Now with respect to the inorganic world two parallel hypotheses of 'creation' have arisen, like those relating to organic nature; but in the former case the determining factor in the choice of ideas has been, not the avocations of the primitive peoples, but the nature of their surroundings.

The dwellers in the valleys of the Euphrates and Tigris could not but be impressed by the great and destructive floods to which those regions were subject; and the inhabitants of the shores and islands of the Aegean Sea, and of the Italian peninsula, were equally conversant with the devastations wrought by volcanic outbursts and earthquake shocks. As great districts were seen to be depopulated by these catastrophies, might not some even more violent cataclysm of the same kind actually destroy all mankind, with the animals and plants, in the comparatively small area then known as 'the world'? The great flood, of which all these nations appear to have retained traditions, was regarded as only the last of such destructive cataclysms; and, in this way, there originated the myth of successive destructions of the face of the earth, each followed by the creation of new stocks of plants and animals. This is the doctrine now known as 'Catastrophism,' which we find prevalent in the earliest traditions and writings of India, Babylonia, Syria and Greece.

But in ancient Egypt quite another class of phenomena was conspicuously presented to the early philosophers of the country. Instead of sudden floods and terrible displays of volcanic and earthquake violence, they witnessed the annual gentle rise and overflowings of their grand river, with its beneficent heritage of new soil; and they soon learned to recognise that Egypt itself—so far as the delta was concerned—was 'the gift of the Nile.'

From the contemplation of these phenomena, the Egyptian sages were gradually led to entertain the idea that all the features of the earth—as they knew it—might have been similarly produced through the slow and constant action of the causes now seen in operation around them. This idea was incorporated in a myth, which was suggested by the slow and gradual transformation of an egg into a perfect, growing organism. The birth of the world was pictured as an act of incubation, and male and female deities were invented to play the part of parents to the infant world. By Pythagoras, who resided for more than twenty years in Egypt, these ideas were introduced to the Greek philosophers, and from that time 'Catastrophism' found a rival in the new doctrine which we shall see has been designated under the names of 'Continuity,' 'Uniformitarianism' or 'Evolution.' How, from the first crude notions of evolution, successive thinkers developed more just and noble conceptions on the subject, has been admirably shown by Professor Osborn in his From the Greeks to Darwin and by Mr. Clodd in his Pioneers of Evolution.

Poets, from Empedocles and Lucretius to Goethe and Tennyson, have sought in their verses to illustrate the beauty of evolutionary ideas; and philosophers, from Aristotle and Strabo to Kant and Herbert Spencer, have recognised the principle of evolution as harmonising with, and growing out of, the highest conceptions of science. Yet it was not till the Nineteenth Century that any serious attempts were made to establish the hypothesis of evolution as a definite theory, based on sound reasoning from careful observation.

It is true that there were men, in advance of their age, who in some cases anticipated to a certain extent this work of establishing the doctrine of evolution on a firm foundation. Thus in Italy, the earliest home of so many sciences, a Carmelite friar, Generelli, reasoning on observations made by his compatriots Fracastoro and Leonardo da Vinci in the Sixteenth Century, Steno and Scilla in the Seventeenth, and Lazzaro Moro and Marsilli in the Eighteenth Century, laid the foundations of a rational system of geology in a work published in 1749 which was characterised alike by courage and eloquence. In France, the illustrious Nicolas Desmarest, from his study of the classical region of the Auvergne, was able to show, in 1777, how the river valleys of that district had been carved out by the rivers that flow in them. Nor were there wanting geologists with similar previsions in Germany and Switzerland.

But none of these early exponents of geological theory came so near to anticipating the work of the Nineteenth Century as did the illustrious James Hutton, whose 'Theory of the Earth,' a first sketch of which was published in 1785, was a splendid exposition of evolution as applied to the inorganic world. Unfortunately, Hutton's theory was linked to the extravagancies of what was known at that day as 'Vulcanism' or 'Plutonism,' in contradistinction to the 'Neptunism' of Werner. Hutton, while rejecting the Wernerian notion of "the aqueous precipitation of basalt," maintained the equally fanciful idea that the consolidation of all strata—clays, sandstones, conglomerates, limestones and even rock-salt—must be ascribed to the action of heat, and that even the formation of chalk-flints and the silicification of fossil wood were due to the injection of molten silica!

What was still more unfortunate in Hutton's case was that, in his enthusiasm, he used expressions which led to his being charged with heresy and even with being an enemy of religion. His writings were further so obscure in style as often to lead to misconception as to their true meaning, while his great work—so far as the fragment which was published goes—contained few records of original observations on which his theory was based.

Dr. Fitton has pointed out very striking coincidences between the writings of Generelli and those of Hutton, and has suggested that the latter may have derived his views from the eloquent Italian friar[10]. But for this suggestion, I think that there is no real foundation. Darwin and Wallace, as we shall see later, were quite unconscious of their having been forestalled in the theory of Natural Selection by Dr. Wells and Patrick Matthew; and Hutton, like his successor Lyell, in all probability arrived, quite independently, and by different lines of reasoning, at conclusions identical with those of Generelli and Desmarest.

Although, as we shall see, Hutton failed to greatly influence the scientific thought of his day, yet all will now agree with Lyell that 'Hutton laboured to give fixed principles to geology, as Newton had succeeded in doing to astronomy[11]'; and with Zittel that 'Hutton's Theory of the Earth is one of the masterpieces in the history of geology[12].'