The chief aim of higher education up to the present time, in most countries, has been a preparation for the subsequent profession, and the acquisition of a certain amount of information and direction for civic duties. The school of the twentieth century will have for its main object the formation of independent thought, the clear understanding of the knowledge acquired, and an insight into the natural connection of phenomena. If the modern state gives every citizen a vote, it should also give him the means of developing his reason by a proper education, in order to make a rational use of his vote for the commonweal.
[CHAPTER XX]
SOLUTION OF THE WORLD-PROBLEMS
A Glance at the Progress of the Nineteenth Century in Solving Cosmic Problems—I. Progress of Astronomy and Cosmology—Physical and Chemical Unity of the Universe—Cosmic Metamorphoses—Evolution of the Planetary System—Analogy of the Phylogenetic Processes on the Earth and on Other Planets—Organic Inhabitants of Other Heavenly Bodies—Periodic Variation in the Making of Worlds—II. Progress of Geology and Palæontology—Neptunism and Vulcanism—Theory of Continuity—III. Progress of Physics and Chemistry—IV. Progress of Biology—Cellular Theory and Theory of Descent—V. Anthropology—Origin of Man—General Conclusion
At the close of our philosophic study of the riddles of the universe we turn with confidence to the answer to the momentous question, How nearly have we approached to a solution of them? What is the value of the immense progress which the passing nineteenth century has made in the knowledge of nature? And what prospect does it open out to us for the future, for the further development of our system in the twentieth century, at the threshold of which we pause? Every unprejudiced thinker who impartially considers the solid progress of our empirical science, and the unity and clearness of our philosophic interpretation of it, will share our view: the nineteenth century has made greater progress in knowledge of the world and in grasp of its nature than all its predecessors; it has solved many great problems that seemed insoluble a hundred years ago; it has opened out to us new provinces of learning, the very existence of which was unsuspected at the beginning of the century. Above all, it has put clearly before our eyes the lofty aim of monistic cosmology, and has pointed out the path which alone will lead us towards it—the way of the exact empirical investigation of facts, and of the critical genetic study of their causes. The great abstract law of mechanical causality, of which our cosmological law—the law of substance—is but another and a concrete expression, now rules the entire universe, as it does the mind of man; it is the steady, immovable pole-star, whose clear light falls on our path through the dark labyrinth of the countless separate phenomena. To see the truth of this more clearly, let us cast a brief glance at the astonishing progress which the chief branches of science have made in this remarkable period.
I.—PROGRESS OF ASTRONOMY
The study of the heavens is the oldest, the study of man the youngest, of the sciences. With regard to himself and the character of his being man only obtained a clear knowledge in the second half of the present century; with regard to the starry heavens, the motions of the planets, and so on, he had acquired astonishing information forty-five hundred years ago. The ancient Chinese, Hindoos, Egyptians, and Chaldæans in the distant East knew more of the science of the spheres than the majority of educated Christians did in the West four thousand years after them. An eclipse of the sun was astronomically observed in China in the year 2697 B.C., and the plane of the ecliptic was determined by means of a gnome eleven hundred years B.C., while Christ himself had no knowledge whatever of astronomy—indeed, he looked out upon heaven and earth, nature and man, from the very narrowest geocentric and anthropocentric point of view. The greatest advance of astronomy is generally, and rightly, said to be the founding of the heliocentric system of Copernicus, whose famous work, De Revolutionibus Orbium Celestium, of itself caused a profound revolution in the minds of thoughtful men. In overthrowing the Ptolemaic system, he destroyed the foundation of the Christian theory, which regarded the earth as the centre of the universe and man as the godlike ruler of the earth. It was natural, therefore, that the Christian clergy, with the pope at its head, should enter upon a fierce struggle with the invaluable discovery of Copernicus. Yet it soon cleared a path for itself, when Kepler and Galileo grounded on it their true “mechanics of the heavens,” and Newton gave it a solid foundation by his theory of gravitation (1686).
A further great advance, comprehending the entire universe, was the application of the idea of evolution to astronomy. It was done by the youthful Kant in 1755; in his famous general natural history and theory of the heavens he undertook the discussion, not only of the “constitution,” but also of the “mechanical origin” of the whole world-structure on Newtonian principles. The splendid Système du Monde of Laplace, who had independently come to the same conclusions as Kant on the world-problem, gave so firm a basis to this new Mécanique Céleste in 1796 that it looked as if nothing entirely new of equal importance was left to be discovered in the nineteenth century. Yet here again it had the honor of opening out entirely new paths and infinitely enlarging our outlook on the universe. The invention of photography and photometry, and especially of spectral analysis (in 1860 by Bunsen and Kirchoff), introduced physics and chemistry into astronomy and led to cosmological conclusions of the utmost importance. It was now made perfectly clear that matter is the same throughout the universe, and that its physical and chemical properties in the most distant stars do not differ from those of the earth under our feet.
The monistic conviction, which we thus arrived at, of the physical and chemical unity of the entire cosmos is certainly one of the most valuable general truths which we owe to astrophysics, the new branch of astronomy which is honorably associated with the name of Friedrich Zöllner. Not less important is the clear knowledge we have obtained that the same laws of mechanical development that we have on the earth rule throughout the infinite universe. A vast, all-embracing metamorphosis goes on continuously in all parts of the universe, just as it is found in the geological history of the earth; it can be traced in the evolution of its living inhabitants as surely as in the history of peoples or in the life of each human individual. In one part of space we perceive, with the aid of our best telescopes, vast nebulæ of glowing, infinitely attenuated gas; we see in them the embryos of heavenly bodies, billions of miles away, in the first stage of their development. In some of these “stellar embryos” the chemical elements do not seem to be differentiated yet, but still buried in the homogeneous primitive matter (prothyl) at an enormous temperature (calculated to run into millions of degrees); it is possible that the original basic “substance” (vide [p. 229]) is not yet divided into ponderable and imponderable matter. In other parts of space we find stars that have cooled down into glowing fluid, and yet others that are cold and rigid; we can tell their stage of evolution approximately by their color. We find stars that are surrounded with rings and moons like Saturn; and we recognize in the luminous ring of the nebula the embryo of a new moon, which has detached itself from the mother-planet, just as the planet was released from the sun.