to-day to range over all its branches with equal thoroughness, and to show their essential unity and connection. Even a genius of the highest type, having an equal command of every branch of science, and largely endowed with the artistic faculty of comprehensive presentation, would be incapable of setting forth a complete view of the cosmos in the space of a moderate volume. My own command of the various branches of science is uneven and defective, so that I can attempt no more than to sketch the general plan of such a world-picture, and point out the pervading unity of its parts, however imperfect be the execution. Thus it is that this work on the world-enigma has something of the character of a sketch-book, in which studies of unequal value are associated. As the material of the book was partly written many years ago, and partly produced for the first time during the last few years, the composition is, unfortunately, uneven at times; repetitions, too, have proved unavoidable. I trust those defects will be overlooked.

In taking leave of my readers, I venture the hope that, through my sincere and conscientious work—in spite of its faults, of which I am not unconscious—I have contributed a little towards the solution of the great enigma. Amid the clash of theories, I trust that I have indicated to many a reader who is absorbed in the zealous pursuit of purely rational knowledge that path which, it is my firm conviction, alone leads to the truth—the path of empirical investigation and of the Monistic Philosophy which is based upon it.

Ernst Haeckel.

Jena, Germany.

PREFACE

The hour is close upon us when we shall commence our retrospect of one of the most wonderful sections of time that was ever measured by the sweep of the earth. Already the expert is at work, dissecting out and studying his particular phase of that vast world of thought and action we call the nineteenth century. Art, literature, commerce, industry, politics, ethics—all have their high interpreters among us; but in the chance of life it has fallen out that there is none to read aright for us, in historic retrospect, what after ages will probably regard as the most salient feature of the nineteenth century—the conflict of theology with philosophy and science. The pens of our Huxleys, and Tyndalls, and Darwins lie where they fell; there is none left in strength among us to sum up the issues of that struggle with knowledge and sympathy.

In these circumstances it has been thought fitting that we should introduce to English readers the latest work of Professor Haeckel. Germany, as the reader will quickly perceive, is witnessing the same strange reaction of thought that we see about us here in England, yet Die Welträthsel found an immediate and very extensive circle of readers. One of the most prominent zoologists of the century, Professor Haeckel, has a unique claim to pronounce with authority, from the scientific side, on what is known as “the conflict of science and religion.” In the contradictory estimates that are urged on us—for the modern ecclesiastic is as emphatic in his assurance that the conflict has ended favorably to theology as the rationalist is with his counter-assertion—the last words of one of the leading combatants of the second half of the century, still, happily, in full vigor of mind, will be heard with respect and close attention.

A glance at the index of the work suffices to indicate its comprehensive character. The judgment of the distinguished scientist cannot fail to have weight on all the topics included; yet the reader will soon discover a vein of exceptionally interesting thought in the chapters on evolution. The evolution of the human body is no longer a matter of serious dispute. It has passed the first two tribunals—those of theology and of an à priori philosophy—and is only challenged at the third and last—that of empirical proof—by the decorative heads of scientific bodies and a few isolated thinkers.

“Apparent rari nantes in gurgite vasto.”

But the question of the evolution of the human mind, or soul, has been successfully divorced from that of the body. Roman Catholic advanced theologians, whose precise terminology demanded a clear position, admit the latter and deny the former categorically. Other theologians, and many philosophers, have still a vague notion that the evidence for the one does not impair their sentimental objection to the other. Dr. Haeckel’s work summarizes the evidence for the evolution of mind in a masterly and profoundly interesting fashion. It seems impossible to follow his broad survey of the psychic world, from protist to man, without bearing away a conviction of the natural origin of every power and content of the human soul.

Translator.

October, 1900.

[Pg xiv]
[Pg 1]

THE RIDDLE OF THE UNIVERSE

CHAPTER I
THE NATURE OF THE PROBLEM

The Condition of Civilization and of Thought at the Close of the Nineteenth Century—Progress of Our Knowledge of Nature, of the Organic and Inorganic Sciences—The Law of Substance and the Law of Evolution—Progress of Technical Science and of Applied Chemistry—Stagnancy in other Departments of Life: Legal and Political Administration, Education, and the Church—Conflict of Reason and Dogma—Anthropism—Cosmological Perspective—Cosmological Theorems—Refutation of the Delusion of Man’s Importance—Number of “World-Riddles”—Criticism of the “Seven” Enigmas—The Way to Solve Them—Function of the Senses and of the Brain—Induction and Deduction—Reason, Sentiment, and Revelation—Philosophy and Science—Experience and Speculation—Dualism and Monism

The close of the nineteenth century offers one of the most remarkable spectacles to the thoughtful observer. All educated people are agreed that it has in many respects immeasurably outstripped its predecessors, and has achieved tasks that were deemed impracticable at its commencement. An entirely new character has been given to the whole of our modern civilization, not only by our astounding theoretical progress in sound knowledge of nature, but also by the remarkably fertile practical application of that knowledge in technical science, industry, commerce, and so forth. On the other hand, however, we have made little or no progress in moral and social life, in comparison with earlier centuries; at times there has been serious reaction. And from this obvious conflict there have arisen, not only an uneasy sense of dismemberment and falseness, but even the danger of grave catastrophes in the political and social world. It is, then, not merely the right, but the sacred duty, of every honorable and humanitarian thinker to devote himself conscientiously to the settlement of that conflict, and to warding off the dangers that it brings in its train. In our conviction this can only be done by a courageous effort to attain the truth, and by the formation of a clear view of the world—a view that shall be based on truth and conformity to reality.

If we recall to mind the imperfect condition of science at the beginning of the century, and compare this with the magnificent structure of its closing years, we are compelled to admit that marvellous progress has been made during its course. Every single branch of science can boast