CHAPTER IX.

SCIENCE: MAN AND HIS DWELLING-PLACE.

FROM the dawn of intelligence three great problems have pressed upon man-his own origin, his relation to the Universe, and to the Absolute. Around these three problems inexhaustible curiosity has ever played, and has given birth to theology, philosophy, science, and, in fact, to all forms of literature. In previous chapters we indicated the attempts made by philosophy to solve these problems. In the absence of science, the outcome of speculation was far from satisfactory. What philosophy can do unaided was seen in the speculations of the greatest of the Greeks. Plato's cosmological speculations are puerile in the extreme, and the history of theology in the pre-scientific era is strewn with deplorable errors. The real value of science in this

connection is seen when we contrast the conceptions of the Universe and Man with the conceptions which prevailed in the days when philosophy and theology, especially when under the influence of Aristotle, were in the ascendant. Then the earth was viewed as the centre of the Universe. Round it revolved the sun and the heavenly bodies. As has been said: "To the Hebrew people the world was flat, and the heavens was a curtain stretched over like the roof of a vast tent, supported by mountain pillars round the borders of the earth. From time to time windows were opened in that roof, through which came the fertilising rains and snows. The celestial luminaries were the adornments of that great curtain which formed the roof of this earthly tabernacle." This conception of the earth passed over from Judaism to Christianity. Along with this conception was another, which extended to comparatively modern times. The earth was supposed to be created within six days. The various species of plants and animals were thought of as special creations, followed by man, whose position was thought of as unique;

between him and the animal a great gulf was fixed.

These views were overthrown by three great scientific conceptions, the Copernican theory, Conservation of Energy, and Evolution. The Copernican theory, by taking the earth from its lofty position as the centre of the Universe, further supplemented by Newton's law and the marvels of celestial evolution, created one of the greatest revolutions in thought in the history of man. Astronomy, in addition to its mind-bewildering revelations, has, by means of the spectroscope, brought to light a fact about the Universe of the greatest possible philosophic as well as scientific significance. The Uni

verse, it is now seen, is characterised by unity of substance. By means of the spectroscope the elements found in the celestial bodies are found to be identical with those upon the earth. Another equally significant fact is that the forces of Nature are not what they were thought to be, distinct entities, but modifications or transformations of one force. The world of Nature is not what it seems, an assemblage of independent things composed

of substances with their respective properties. The multiform energies of Nature are reducible to one form of energy, protean in its manifestations, and to whose conservation and transformation under appropriate conditions all phenomena are due. Thus to the unity of substance of which the Universe is composed has to be added unity of force. Still another unity has to be added, unity of process.

To Herbert Spencer belongs the honour of the discovery of this unity. Under the name of evolution, he has shown that the Universe and all that it contains has reached its present stage through a process of evolution from the simple to the complex, through successive differentiations and integrations. According to the Spencerian view, the Universe is a complex complex unity which, when reduced to its ultimate analysis, is seen to be one fact-the redistribution of Matter and Motion, all phenomena being complex aspects of that one fact. In studying the Earth, man's dwelling-place, science is really engaged in tracing through all phenomena unity of substance, unity of force, and unity of

process.

Unless the reader comes to science with these conceptions, he will fail entirely to understand the development of the Earth from its primitive nebula stage through the geologic and biologic stages, till we reach the era of humanity, with its marvellous activities and results.

The law of evolution holds good from star to soul. The primitive or nebulous stage of the earth can be admirably studied in Spencer's First Principles,' where also the reader will find a concise account of the agencies which went to the making of the earth geologically. Those who wish to go deeper into the subject, and who desire to get knowledge of the nature of the forces, as well as of the processes of terrestrial evolution, will find it necessary to go to the works of Joule, Mayer, Grove, Helmholtz, Kelvin, and Tyndall, and others, where the constitution of matter is fully discussed from various points of view, mechanical and chemical-works which prepare the student for recent speculations on Radium. One of the most extraordinary features of modern science has been the application of evolution,