The two groups of functions of matter, which we have opposed in this table, may, to some extent, be regarded as the outcome of the first “division of labor” in the development of matter, the “primary ergonomy of matter.” But this distinction must not be supposed to involve an absolute separation of the two antithetic groups; they always retain their connection, and are in constant reciprocal action. It is well known that the optical and electrical phenomena of ether are closely connected with mechanical and chemical changes in ponderable elements; the radiant heat of ether may be directly converted into the mechanical heat of the mass; gravitation is impossible unless the ether effects the mutual attraction of the separated atoms, because we cannot admit the idea of an actio in distans. In like manner, the conversion of one form of energy into another, as indicated in the law of the persistence of force, illustrates the constant reciprocity of the two chief types of substance, ether and mass.
The great law of nature, which, under the title of the “law of substance,” we put at the head of all physical considerations, was conceived as the law of “the persistence of force” by Robert Meyer, who first formulated it, and Helmholtz, who continued the work. Another German scientist, Friedrich Mohr, of Bonn, had clearly outlined it in its main features ten years earlier (1837). The old idea of force was, after a time, differentiated by modern physics from that of energy, which was at first synonymous with it. Hence the law is now usually called the “law of the persistence of energy.” However, this finer distinction need not enter into the general consideration, to which I must confine myself here, and into the question of the great principle of the “persistence of substance.” The interested reader will find a very clear treatment of the question in Tyndall’s excellent paper on “The Fundamental Law of Nature,” in his Fragments of Science. It fully explains the broad significance of this profound cosmic law, and points out its application to the main problems of very different branches of science. We shall confine our attention to the important fact that the “principle of energy” and the correlative idea of the unity of natural forces, on the basis of a common origin, are now accepted by all competent physicists, and are regarded as the greatest advance of physics in the nineteenth century. We now know that heat, sound, light, chemical action, electricity, and magnetism are all modes of motion. We can, by a certain apparatus, convert any one of these forces into another, and prove by an accurate measurement that not a single particle of energy is lost in the process.
The sum-total of force or energy in the universe remains constant, no matter what changes take place around us; it is eternal and infinite, like the matter on which it is inseparably dependent. The whole drama of nature apparently consists in an alternation of movement and repose; yet the bodies at rest have an inalienable quantity of force, just as truly as those that are in motion. It is in this movement that the potential energy of the former is converted into the kinetic energy of the latter. “As the principle of the persistence of force takes into account repulsion as well as attraction, it affirms that the mechanical value of the potential energy and the kinetic energy in the material world is a constant quantity. To put it briefly, the force of the universe is divided into two parts, which may be mutually converted, according to a fixed relation of value. The diminution of the one involves the increase of the other; the total value remains unchanged in the universe.” The potential energy and the actual, or kinetic, energy are being continually transformed from one condition to the other; but the infinite sum of force in the world at large never suffers the slightest curtailment.
Once modern physics had established the law of substance as far as the simpler relations of inorganic bodies are concerned, physiology took up the story, and proved its application to the entire province of the organic world. It showed that all the vital activities of the organism—without exception—are based on a constant “reciprocity of force” and a correlative change of material, or metabolism, just as much as the simplest processes in “lifeless” bodies. Not only the growth and the nutrition of plants and animals, but even their functions of sensation and movement, their sense-action and psychic life, depend on the conversion of potential into kinetic energy, and vice versâ. This supreme law dominates also those elaborate performances of the nervous system which we call, in the higher animals and man, “the action of the mind.”
Our monistic view, that the great cosmic law applies throughout the whole of nature, is of the highest moment. For it not only involves, on its positive side, the essential unity of the cosmos and the causal connection of all phenomena that come within our cognizance, but it also, in a negative way, marks the highest intellectual progress, in that it definitely rules out the three central dogmas of metaphysics—God, freedom, and immortality. In assigning mechanical causes to phenomena everywhere, the law of substance comes into line with the universal law of causality.
CHAPTER XIII
THE EVOLUTION OF THE WORLD
The Notion of Creation—Miracles—Creation of the Whole Universe and of its Various Parts—Creation of Substance (Cosmological Creation)—Deism: One Creative Day—Creation of Separate Entities—Five Forms of Ontological Creationism—Theory of Evolution—I. Monistic Cosmogony—Beginning and End of the World—The Infinity and Eternity of the Universe—Space and Time—Universum perpetuum mobile—Entropy of the Universe—II. Monistic Geogeny—History of the Inorganic and Organic Worlds—III. Monistic Biogeny—Transformism and the Theory of Descent: Lamarck and Darwin—IV. Monistic Anthropogeny—Origin of Man
The greatest, vastest, and most difficult of all cosmic problems is that of the origin and development of the world—the “question of creation,” in a word. Even to the solution of this most difficult world-riddle the nineteenth century has contributed more than all its predecessors; in a certain sense, indeed, it has found the solution. We have at least attained to a clear view of the fact that all the partial questions of creation are indivisibly connected, that they represent one single, comprehensive “cosmic problem,” and that the key to this problem is found in the one magic word—evolution. The great questions of the creation of man, the creation of the animals and plants, the creation of the earth and the sun, etc., are all parts of the general question, What is the origin of the whole world? Has it been created by supernatural power, or has it been evolved by a natural process? What are the causes and the manner of this evolution? If we succeed in finding the correct answer to one of these questions, we have, according to our monistic conception of the world, cast a brilliant light on the solution of them all, and on the entire cosmic problem.
The current opinion as to the origin of the world in earlier ages was almost a universal belief in creation. This belief has been expressed in thousands of interesting, more or less fabulous, legends, poems, cosmogonies, and myths. A few great philosophers were devoid of it, especially those remarkable free-thinkers of classical antiquity who first conceived the idea of natural evolution. All the creation-myths, on the contrary, were of a supernatural, miraculous, and transcendental character. Incompetent, as it was, to investigate for itself the nature of the world and its origin by natural causes, the undeveloped mind naturally had recourse to the idea of miracle. In most of these creation-myths anthropism was blended with the belief in the miraculous. The creator was supposed to have constructed the world on a definite plan, just as man accomplishes his artificial constructions; the conception of the creator was generally completely anthropomorphic, a palpable “anthropistic creationism.” The “all-mighty maker of heaven and earth,” as he is called in Genesis and the Catechism, is just as humanly conceived as the modern creator of Agassiz and Reinke, or the intelligent “engineer” of other recent biologists.
Entering more fully into the notion of creation, we can distinguish as two entirely different acts the production of the universe as a whole and the partial production of its various parts, in harmony with Spinoza’s idea of substance (the universe) and accidents (or modes, the individual phenomena of substance). This distinction is of great importance, because there are many eminent philosophers who admit the one and reject the other.
According to this creationist theory, then, God has “made the world out of nothing.” It is supposed that God (a rational, but immaterial, being) existed by himself for an eternity before he resolved to create the world. Some supporters of the theory restrict God’s creative function to one single act; they believe that this extramundane God (the rest of whose life is shrouded in mystery) created the substance of the world in a single moment, endowed it with the faculty of the most extensive evolution, and troubled no further about it. This view may be found, for instance, in the English Deists in many forms. It approaches very close to our monistic theory of evolution, only abandoning it in the one instant in which God accomplished the creation. Other creationists contend that God did not confine himself to the mere creation of matter, but that he continues to be operative as the “sustainer and ruler of the world.” Different modifications of this belief are found, some approaching very close to pantheism and others to complete theism. All these and similar forms of belief in creation are incompatible with the law of the persistence of matter and force; that law knows nothing of a beginning.
It is interesting to note that E. du Bois-Reymond has identified himself with this cosmological creationism in his latest speech (on “Neovitalism,” 1894). “It is more consonant with the divine omnipotence,” he says, “to assume that it created the whole material of the world in one creative act unthinkable ages ago in such wise that it should be endowed with inviolable laws to control the origin and the progress of living things—that, for instance, here on earth rudimentary organisms should arise from which, without further assistance, the whole of living nature could be evolved, from a primitive bacillus to the graceful palm-wood, from a primitive micrococcus to Solomon’s lovely wives or to the brain of Newton. Thus we are content with one creative day, and we derive organic nature mechanically, without the aid of either old or new vitalism.” Du Bois-Reymond here shows, as in the question of consciousness, the shallow and illogical character of his monistic thought.
According to another still prevalent theory, which may be called “ontological creationism,” God not only created the world at large, but also its separate contents. In the Christian world the old Semitic legend of creation, taken from Genesis, is still very widely accepted; even among modern scientists it finds an adherent here and there. I have fully entered into the criticism of it in the first chapter of my Natural History of Creation. The following theories may be enumerated as the most interesting modifications of this ontological creationism:
I. Dualistic creation.—God restricted his interference to two creative acts. First he created the inorganic world, mere dead substance, to which alone the law of energy applies, working blindly and aimlessly in the mechanism of material things and the building of the mountains; then God attained intelligence and communicated it to the purposive intelligent forces which initiate and control organic evolution.[26]
II. Trialistic creation.—God made the world in three creative acts: (a) the creation of the heavens—the extra-terrestrial world, (b) the creation of the earth (as the centre of the world) and of its living inhabitants, and (c) the creation of man (in the image and likeness of God). This dogma is still widely prevalent among theologians and other “educated” people; it is taught as the truth in many of our schools.
III. Heptameral creation; a creation in seven days (teste Moses).—Although few educated people really believe in this Mosaic myth now, it is still firmly impressed on our children in the biblical lessons of their earliest years. The numerous attempts that have been made, especially in England, to harmonize it with the modern theory of evolution have entirely failed. It obtained some importance in science when Linné adopted it in the establishment of his system, and based his definition of organic species (which he considered to be unchangeable) on it: “There are as many different species of animals and plants as there were different forms created in the beginning by the Infinite.” This dogma was pretty generally held until the time of Darwin (1859), although Lamarck had already proved its untenability in 1809.
IV. Periodic creation.—At the beginning of each period of the earth’s history the whole population of animals and plants was created anew, and destroyed by a general catastrophe at its close; there were as many general creative acts as there are distinct geological periods (the catastrophic theory of Cuvier [1818] and Louis Agassiz [1858]). Palæontology, which seemed to support this theory in its more imperfect stage, has since completely refuted it.
V. Individual creation.—Every single man—and every individual animal and plant—does not arise by a natural process of growth, but is created by the favor of God. This view of creation is still often met with in journals, especially in the “births” column. The special talents and features of our children are often gratefully acknowledged to be “gifts of God”; their hereditary defects fit into another theory.
The error of these creation-legends and the cognate belief in miracles must have been apparent to thoughtful minds at an early period; more than two thousand years ago we find that many attempts were made to replace them by a rational theory, and to explain the origin of the world by natural causes. In the front rank, once more, we must place the leaders of the Ionic school, with Democritus, Heraclitus, Empedocles, Aristotle, Lucretius, and other ancient philosophers. The first imperfect attempts which they made astonish us, in a measure, by the flashes of mental light in which they anticipate modern ideas. It must be remembered that classical antiquity had not that solid groundwork for scientific speculation which has been provided by the countless observations and experiments of modern scientists. During the Middle Ages—especially during the domination of the papacy—scientific work in this direction entirely ceased. The torture and the stake of the Inquisition insured that an unconditional belief in the Hebrew mythology should be the final answer to all the questions of creation. Even the phenomena which led directly to the observation of the facts of evolution—the embryology of the plant and the animal, and of man—remained unnoticed, or only excited the interest of an occasional keen observer; but their discoveries were ignored or forgotten. Moreover, the path to a correct knowledge of natural development was barred by the dominant theory of preformation, the dogma which held that the characteristic form and structure of each animal and plant were already sketched in miniature in the germ (cf. p. 54).
The science which we now call the science of evolution (in the broadest sense) is, both in its general outline and in its separate parts, a child of the nineteenth century; it is one of its most momentous and most brilliant achievements. Almost unknown in the preceding century, this theory has now become the sure foundation of our whole world-system. I have treated it exhaustively in my General Morphology (1866), more popularly in my Natural History of Creation (1868), and in its special application to man in my Anthropogeny (1874). Here I shall restrict myself to a brief survey of the chief advances which the science has made in the course of the century. It falls into four sections, according to the nature of its object; that is, it deals with the natural origin of (1) the cosmos, (2) the earth, (3) terrestrial forms of life, and (4) man.
I.—MONISTIC COSMOGONY
The first attempt to explain the constitution and the mechanical origin of the world in a simple manner by “Newtonian laws”—that is, by mathematical and physical laws—was made by Immanuel Kant in the famous work of his youth (1755), General History of the Earth and Theory of the Heavens. Unfortunately, this distinguished and daring work remained almost unknown for ninety years; it was only disinterred in 1845 by Alexander Humboldt in the first volume of his Cosmos. In the mean time the great French mathematician, Pierre Laplace, had arrived independently at similar views to those of Kant, and he gave them a mathematical foundation in his Exposition du Système du Monde (1796). His chief work, the Mécanique Céleste, appeared a hundred years ago. The analogous features of the cosmogony of Kant and Laplace consist, as is well known, in a mechanical explanation of the movements of the planets, and the conclusion which is drawn therefrom, that all the cosmic bodies were formed originally by a condensation of rotating nebulous spheres. This “nebular hypothesis” has been much improved and supplemented since, but it is still the best of all the attempts to explain the origin of the world on monistic and mechanical lines. It has recently been strongly confirmed and enlarged by the theory that this cosmogonic process did not simply take place once, but is periodically repeated. While new cosmic bodies arise and develop out of rotating masses of nebula in some parts of the universe, in other parts old, extinct, frigid suns come into collision, and are once more reduced by the heat generated to the condition of nebulæ.
Nearly all the older and the more recent cosmogonies, including most of those which were inspired by Kant and Laplace, started from the popular idea that the world had had a beginning. Hence, according to a widespread version of the nebular hypothesis, “in the beginning” was made a vast nebula of infinitely attenuated and light material, and at a certain moment (“countless ages ago”) a movement of rotation was imparted to this mass. Given this “first beginning” of the cosmogonic movement, it is easy, on mechanical principles, to deduce and mathematically establish the further phenomena of the formation of the cosmic bodies, the separation of the planets, and so forth. This first “origin of movement” is Du Bois-Reymond’s second “world-enigma”; he regards it as transcendental. Many other scientists and philosophers are equally helpless before this difficulty; they resign themselves to the notion that we have here a primary “supernatural impetus” to the scheme of things, a “miracle.”
In our opinion, this second “world-enigma” is solved by the recognition that movement is as innate and original a property of substance as is sensation. The proof of this monistic assumption is found, first, in the law of substance, and, secondly, in the discoveries which astronomy and physics have made in the latter half of the century. By the spectral analysis of Bunsen and Kirchhoff (1860) we have found, not only that the millions of bodies, which fill the infinity of space, are of the same material as our own sun and earth, but also that they are in various stages of evolution; we have obtained by its aid information as to the movements and distances of the stars, which the telescope would never have given us. Moreover, the telescope itself has been vastly improved, and has, in alliance with photography, made a host of scientific discoveries of which no one dreamed at the beginning of the century. In particular, a closer acquaintance with comets, meteorites, star-clusters, and nebulæ has helped us to realize the great significance of the smaller bodies which are found in millions in the space between the stars.
We now know that the paths of the millions of heavenly bodies are changeable, and to some extent irregular, whereas the planetary system was formerly thought to be constant, and the rotating spheres were described as pursuing their orbits in eternal regularity. Astro-physics owes much of its triumph to the immense progress of other branches of physics, of optics, and electricity, and especially of the theory of ether. And here, again, our supreme law of substance is found to be one of the most valuable achievements of modern science. We now know that it rules unconditionally in the most distant reaches of space, just as it does in our planetary system, in the most minute particle of the earth as well as in the smallest cell of our human frame. We are, moreover, justified in concluding, if we are not logically compelled to conclude, that the persistence of matter and force has held good throughout all time as it does to-day. Through all eternity the infinite universe has been, and is, subject to the law of substance.
From this great progress of astronomy and physics, which mutually elucidate and supplement each other, we draw a series of most important conclusions with regard to the constitution and evolution of the cosmos, and the persistence and transformation of substance. Let us put them briefly in the following theses:
I. The extent of the universe is infinite and unbounded; it is empty in no part, but everywhere filled with substance.
II. The duration of the world is equally infinite and unbounded; it has no beginning and no end: it is eternity.
III. Substance is everywhere and always in uninterrupted movement and transformation: nowhere is there perfect repose and rigidity; yet the infinite quantity of matter and of eternally changing force remains constant.
IV. This universal movement of substance in space takes the form of an eternal cycle or of a periodical process of evolution.
V. The phases of this evolution consist in a periodic change of consistency, of which the first outcome is the primary division into mass and ether—the ergonomy of ponderable and imponderable matter.
VI. This division is effected by a progressive condensation of matter as the formation of countless infinitesimal “centres of condensation,” in which the inherent primitive properties of substance—feeling and inclination—are the active causes.
VII. While minute and then larger bodies are being formed by this pyknotic process in one part of space, and the intermediate ether increases its strain, the opposite process—the destruction of cosmic bodies by collision—is taking place in another quarter.
VIII. The immense quantity of heat which is generated in this mechanical process of the collision of swiftly moving bodies represents the new kinetic energy which effects the movement of the resultant nebulæ and the construction of new rotating bodies. The eternal drama begins afresh. Even our mother earth, which was formed of part of the gyrating solar system millions of ages ago, will grow cold and lifeless after the lapse of further millions, and, gradually narrowing its orbit, will fall eventually into the sun.
It seems to me that these modern discoveries as to the periodic decay and re-birth of cosmic bodies, which we owe to the most recent advance of physics and astronomy, associated with the law of substance, are especially important in giving us a clear insight into the universal cosmic process of evolution. In their light our earth shrinks into the slender proportions of a “mote in the sunbeam,” of which unnumbered millions chase each other through the vast depths of space. Our own “human nature,” which exalted itself into an image of God in its anthropistic illusion, sinks to the level of a placental mammal, which has no more value for the universe at large than the ant, the fly of a summer’s day, the microscopic infusorium, or the smallest bacillus. Humanity is but a transitory phase of the evolution of an eternal substance, a particular phenomenal form of matter and energy, the true proportion of which we soon perceive when we set it on the background of infinite space and eternal time.
Since Kant explained space and time to be merely “forms of perception”—space the form of external, time of internal, sensitivity—there has been a keen controversy, which still continues, over this important problem. A large section of modern metaphysicians have persuaded themselves that this “critical fact” possesses a great importance as the starting-point of “a purely idealist theory of knowledge,” and that, consequently, the natural opinion of the ordinary healthy mind as to the reality of time and space is swept aside. This narrow and ultra-idealist conception of time and space has become a prolific source of error. It overlooks the fact that Kant only touched one side of the problem, the subjective side, in that theory, and recognized the equal validity of its objective side. “Time and space,” he said, “have empirical reality, but transcendental ideality.” Our modern monism is quite compatible with this thesis of Kant’s, but not with the one-sided exaggeration of the subjective aspect of the problem; the latter leads logically to the absurd idealism that culminates in Berkeley’s thesis, “Bodies are but ideas; their essence is in their perception.” The thesis should be read thus: “Bodies are only ideas for my personal consciousness; their existence is just as real as that of my organs of thought, the ganglionic cells in the gray bed of my brain, which receive the impress of bodies on my sense-organs and form those ideas by association of the impressions.” It is just as easy to doubt or to deny the reality of my own consciousness as to doubt that of time and space. In the delirium of fever, in hallucinations, in dreams, and in double-consciousness, I take ideas to be true which are merely fancies. I mistake my own personality for another (vide p. 185); Descartes’ famous Cogito ergo sum applies no longer. On the other hand, the reality of time and space is now fully established by that expansion of our philosophy which we owe to the law of substance and to our monistic cosmogony. When we have happily got rid of the untenable idea of “empty space,” there remains as the infinite “space-filling”-medium matter, in its two forms of ether and mass. So also we find a “time-filling” event in the eternal movement, or genetic energy, which reveals itself in the uninterrupted evolution of substance, in the perpetuum mobile of the universe.
As a body which has been set in motion continues to move as long as no external agency interferes with it, the idea was conceived long ago of constructing an apparatus which should illustrate perpetual motion. The fact was overlooked that every movement meets with external impediments and gradually ceases, unless a new impetus is given to it from without and a new force is introduced to counteract the impediments. Thus, for instance, a pendulum would swing backward and forward for an eternity at the same speed if the resistance of the atmosphere and the friction at the point it hangs from did not gradually deprive it of the mechanical kinetic energy of its motion and convert it into heat. We have to furnish it with fresh mechanical energy by a spring (or, as in the pendulum-clock, by the drag of a weight). Hence it is impossible to construct a machine that would produce, without external aid, a surplus of energy by which it could keep itself going. Every attempt to make such a perpetuum mobile must necessarily fail; the discovery of the law of substance showed, in addition, the theoretical impossibility of it.
The case is different, however, when we turn to the world at large, the boundless universe that is in eternal movement. The infinite matter, which fills it objectively, is what we call space in our subjective impression of it; time is our subjective conception of its eternal movement, which is, objectively, a periodic, cyclic evolution. These two “forms of perception” teach us the infinity and eternity of the universe. That is, moreover, equal to saying that the universe itself is a perpetuum mobile. This infinite and eternal “machine of the universe” sustains itself in eternal and uninterrupted movement, because every impediment is compensated by an “equivalence of energy,” and the unlimited sum of kinetic and potential energy remains always the same. The law of the persistence of force proves also that the idea of a perpetuum mobile is just as applicable to, and as significant for, the cosmos as a whole as it is impossible for the isolated action of any part of it. Hence the theory of entropy is likewise untenable.
The able founder of the mechanical theory of heat (1850), Clausius, embodied the momentous contents of this important theory in two theses. The first runs: “The energy of the universe is constant”—that is one-half of our law of substance, the principle of energy (vide p. 230). The second thesis is: “The energy of the universe tends towards a maximum.” In my opinion this second assertion is just as erroneous as the first is true. In the theory of Clausius the entire energy of the universe is of two kinds, one of which (heat of the higher degree, mechanical, electrical, chemical energy, etc.) is partly convertible into work, but the other is not; the latter energy, already converted into heat and distributed in the cooler masses, is irrevocably lost as far as any further work is concerned. Clausius calls this unconsumed energy, which is no longer available for mechanical work, entropy (that is, force that is directed inward); it is continually increasing at the cost of the other half. As, therefore, the mechanical energy of the universe is daily being transformed into heat, and this cannot be reconverted into mechanical force, the sum of heat and energy in the universe must continually tend to be reduced and dissipated. All difference of temperature must ultimately disappear, and the completely latent heat must be equally distributed through one inert mass of motionless matter. All organic life and movement must cease when this maximum of entropy has been reached. That would be a real “end of the world.”
If this theory of entropy were true, we should have a “beginning” corresponding to this assumed “end” of the world—a minimum of entropy, in which the differences in temperature of the various parts of the cosmos would be at a maximum. Both ideas are quite untenable in the light of our monistic and consistent theory of the eternal cosmogenetic process; both contradict the law of substance. There is neither beginning nor end of the world. The universe is infinite, and eternally in motion; the conversion of kinetic into potential energy, and vicissim, goes on uninterruptedly; and the sum of this actual and potential energy remains constant. The second thesis of the mechanical theory of heat contradicts the first, and so must be rejected.
The representatives of the theory of entropy are quite correct as long as they confine themselves to distinct processes, in which, under certain conditions, the latent heat cannot be reconverted into work. Thus, for instance, in the steam-engine the heat can only be converted into mechanical work when it passes from a warmer body (steam) into a cooler (water); the process cannot be reversed. In the world at large, however, quite other conditions obtain—conditions which permit the reconversion of latent heat into mechanical work. For instance, in the collision of two heavenly bodies, which rush towards each other at inconceivable speed, enormous quantities of heat are liberated, while the pulverized masses are hurled and scattered about space. The eternal drama begins afresh—the rotating mass, the condensation of its parts, the formation of new meteorites, their combination into larger bodies, and so on.
II.—MONISTIC GEOGENY
The history of the earth, of which we are now going to make a brief survey, is only a minute section of the history of the cosmos. Like the latter, it has been the object of philosophic speculation and mythological fantasy for many thousand years. Its true scientific study, however, is much younger; it belongs, for the most part, to the nineteenth century. The fact that the earth is a planet revolving round the sun was determined by the system of Copernicus (1543); Galilei, Kepler, and other great astronomers, mathematically determined its distance from the sun, the laws of its motion, and so forth. Kant and Laplace indicated, in their cosmogony, the way in which the earth had been developed from the parent sun. But the later history of the earth, the formation of its crust, the origin of its seas and continents, its mountains and deserts, was rarely made the subject of serious scientific research in the eighteenth century, and in the first two decades of the nineteenth. As a rule, men were satisfied with unreliable conjectures or with the traditional story of creation; once more the Mosaic legend barred the way to an independent investigation.
In 1822 an important work appeared, which followed the same method in the scientific investigation of the history of the earth that had already proved the most fertile—the ontological method, or the principle of “actualism.” It consists in a careful study and manipulation of actual phenomena with a view to the elucidation of the analogous historical processes of the past. The Society of Science at Göttingen had offered a prize in 1818 for “the most searching and comprehensive inquiry into the changes in the earth’s crust which are historically demonstrable, and the application which may be made of a knowledge of them in the investigation of the terrestrial revolutions which lie beyond the range of history.” This prize was obtained by Karl Hoff, of Gotha, for his distinguished work, History of the Natural Changes in the Crust of the Earth in the Light of Tradition (1822-34). Sir Charles Lyell then applied this ontological or actualistic method with great success to the whole province of geology; his Principles of Geology (1830) laid the firm foundation on which the fabric of the history of the earth was so happily erected. The important geogenetic research of Alexander Humboldt, Leopold Buch, Gustav Bischof, Edward Süss, and other geologists, were wholly based on the empirical foundation and the speculative principles of Karl Hoff and Charles Lyell. They cleared the way for purely rational science in the field of geology; they removed the obstacles that had been put in the path by mythological fancy and religious tradition, especially by the Bible and its legends. I have already discussed the merits of Lyell, and his relations with his friend Charles Darwin, in the sixteenth and seventeenth chapters of my Natural History of Creation, and must refer the reader to the standard works on geology for a further acquaintance with the history of the earth and the great progress which dynamical and historical geology have made during the century.
The first division of the history of the earth must be a separation of inorganic and organic geogeny; the latter begins with the first appearance of living things on our planet. The earlier section, the inorganic history of the earth, ran much the same course as that of the other planets of our system. They were all cast off as rings of nebula at the equator of the rotating solar mass, and gradually condensed into independent bodies. After cooling down a little, the glowing ball of the earth was formed out of the gaseous mass, and eventually, as the heat continued to radiate out into space, there was formed at its surface the thin solid crust on which we live. When the temperature at the surface had gone down to a certain point, the water descended upon it from the environing clouds of steam, and thus the first condition was secured for the rise of organic life. Many million years—certainly more than a hundred—have passed since this important process of the formation of water took place, introducing the third section of cosmogony, which we call biogeny.
III.—MONISTIC BIOGENY
The third phase of the evolution of the world opens with the advent of organisms on our planet, and continues uninterrupted from that point until the present day. The great problems which this most interesting part of the earth’s history suggests to us were still thought insoluble at the beginning of the nineteenth century, or, at least, so difficult that their solution seemed to be extremely remote. Now, at the close of the century, we can affirm with legitimate pride that they have been substantially solved by modern biology and its theory of transformism; indeed, many of the phenomena of the organic world are now interpreted on physical principles as completely as the familiar physical phenomena of inorganic nature. The merit of making the first important step in this difficult path and of pointing out the way to the monistic solution of all the problems of biology must be accorded to the great French scientist, Jean Lamarck; it was in 1809, the year of the birth of Charles Darwin, that he published his famous Philosophie Zoologique. In this original work not only is a splendid effort made to interpret all the phenomena of organic life from a monistic and physical point of view, but the path is opened which alone leads to the solution of the greatest enigma of this branch of science—the problem of the natural origin of organic species. Lamarck, who had an equally extensive empirical acquaintance with zoology and botany, drew the first sketch of the theory of descent; he showed that all the countless members of the plant and animal kingdoms have arisen by slow transformation from simple, common ancestral types, and that it is the gradual modification of forms by adaptation, in reciprocal action with heredity, which has brought about this secular metamorphosis.
I have fully appreciated the merit of Lamarck in the fifth chapter, and of Darwin in the sixth and seventh chapters, of the Natural History of Creation. Darwin, fifty years afterwards, not only gave a solid foundation to all the essential parts of the theory of descent, but he filled up the lacunae of Lamarck’s work by his theory of selection. Darwin reaped abundantly the success that Lamarck had never seen, with all his merit. His epoch-making work on The Origin of Species by Natural Selection has transformed modern biology from its very foundations, in the course of the last forty years, and has raised it to a stage of development that yields to no other science in existence. Darwin is the Copernicus of the organic world, as I said in 1868, and E. du Bois-Reymond repeated fifteen years afterwards.[27]
IV.—MONISTIC ANTHROPOGENY
The fourth and last phase of the world’s history must be for us men that latest period of time which has witnessed the development of our own race. Lamarck (1809) had already recognized that this evolution is only rationally conceivable as the outcome of a natural process, by “descent from the apes,” our next of kin among the mammals. Huxley then proved, in his famous essay on The Place of Man in Nature, that this momentous thesis is an inevitable consequence of the theory of descent, and is thoroughly established by the facts of anatomy, embryology, and palæontology. He considered this “question of all questions” to be substantially answered. Darwin followed with a brilliant discussion of the question under many aspects in his Descent of Man (1871). I had myself devoted a special chapter to this important problem of the science of evolution in my General Morphology (1866). In 1874 I published my Anthropogeny, which contains the first attempt to trace the descent of man through the entire chain of his ancestry right up to the earliest archigonous monera; the attempt was based equally on the three great “documents” of evolutionary science—anatomy, embryology, and palæontology. The progress we have made in anthropogenetic research during the last few years is described in the paper which I read on “Our Present Knowledge of the Origin of Man” at the International Congress of Zoologists at Cambridge in 1898.[28]
CHAPTER XIV
THE UNITY OF NATURE
The Monism of the Cosmos—Essential Unity of Organic and Inorganic Nature—Carbon-Theory—The Hypothesis of Abiogenesis—Mechanical and Purposive Causes—Mechanicism and Teleology in Kant’s Works—Design in the Organic and Inorganic Worlds—Vitalism—Neovitalism—Dysteleology (the Moral of the Rudimentary Organs)—Absence of Design in, and Imperfection of, Nature—Telic Action in Organized Bodies—Its Absence in Ontogeny and Phylogeny—The Platonist “Ideas”—No Moral Order Discoverable in the History of the Organic World, of the Vertebrates, or of the Human Race—Prevision—Design and Chance
One of the first things to be proved by the law of substance is the basic fact that any natural force can be directly or indirectly converted into any other. Mechanical and chemical energy, sound and heat, light and electricity, are mutually convertible; they seem to be but different modes of one and the same fundamental force or energy. Thence follows the important thesis of the unity of all natural forces, or, as it may also be expressed, the “monism of energy.” This fundamental principle is now generally recognized in the entire province of physics and chemistry, as far as it applies to inorganic substances.
It seems to be otherwise with the organic world and its wealth of color and form. It is, of course, obvious that a great part of the phenomena of life may be immediately traced to mechanical and chemical energy, and to the effects of electricity and light. For other vital processes, however, especially for psychic activity and consciousness, such an interpretation is vigorously contested. Yet the modern science of evolution has achieved the task of constructing a bridge between these two apparently irreconcilable provinces. We are now certain that all the phenomena of organic life are subject to the universal law of substance no less than the phenomena of the inorganic universe.
The unity of nature which necessarily follows, and the demolition of the earlier dualism, are certainly among the most valuable results of modern evolution. Thirty-three years ago I made an exhaustive effort to establish this “monism of the cosmos” and the essential unity of organic and inorganic nature by a thorough, critical demonstration, and a comparison of the accordance of these two great divisions of nature with regard to matter, form, and force.[29] A short epitome of the result is given in the fifteenth chapter of my Natural History of Creation. The views I put forward are accepted by the majority of modern scientists, but an attempt has been made in many quarters lately to dispute them and to maintain the old antithesis of the two divisions of nature. The ablest of these is to be found in the recent Welt als That of the botanist Reinke. It defends pure cosmological dualism with admirable lucidity and consistency, and only goes to prove how utterly untenable the teleological system is that is connected therewith. According to the author, physical and chemical forces alone are at work in the entire field of inorganic nature, while in the organic world we find “intelligent forces,” regulative or dominant forces. The law of substance is supposed to apply to the one, but not to the other. On the whole, it is a question of the old antithesis of a mechanical and a teleological system. But before we go more fully into it, let us glance briefly at two other theories, which seem to me to be of great importance in the decision of that controversy—the carbon-theory and the theory of spontaneous generation.
Physiological chemistry has, after countless analyses, established the following five facts during the last forty years:
I. No other elements are found in organic bodies than those of the inorganic world.
II. The combinations of elements which are peculiar to organisms, and which are responsible for their vital phenomena, are compound protoplasmic substances, of the group of albuminates.
III. Organic life itself is a chemico-physical process, based on the metabolism (or interchange of material) of these albuminates.
IV. The only element which is capable of building up these compound albuminates, in combination with other elements (oxygen, hydrogen, nitrogen, and sulphur), is carbon.
V. These protoplasmic compounds of carbon are distinguished from most other chemical combinations by their very intricate molecular structure, their instability, and their jelly-like consistency.
On the basis of these five fundamental facts the following “carbon-theory” was erected thirty-three years ago: “The peculiar chemico-physical properties of carbon—especially the fluidity and the facility of decomposition of the most elaborate albuminoid compounds of carbon—are the sole and the mechanical causes of the specific phenomena of movement, which distinguish organic from inorganic substances, and which are called life, in the usual sense of the word” (see The Natural History of Creation). Although this “carbon-theory” is warmly disputed in some quarters, no better monistic theory has yet appeared to replace it. We have now a much better and more thorough knowledge of the physiological relations of cell-life, and of the chemistry and physics of the living protoplasm, than we had thirty-three years ago, and so it is possible to make a more confident and effective defence of the carbon-theory.
The old idea of spontaneous generation is now taken in many different senses. It is owing to this indistinctness of the idea, and its application to so many different hypotheses, that the problem is one of the most contentious and confused of the science of the day. I restrict the idea of spontaneous generation—also called abiogenesis or archigony—to the first development of living protoplasm out of inorganic carbonates, and distinguish two phases in this “beginning of biogenesis”: (1) autogony, or the rise of the simplest protoplasmic substances in a formative fluid, and (2) plasmogony, the differentiation of individual primitive organisms out of these protoplasmic compounds, in the form of monera. I have treated this important, though difficult, problem so exhaustively in the fifteenth chapter of my Natural History of Creation that I may content myself here with referring to it. There is also a very searching and severely scientific inquiry into it in my General Morphology (1866). Naegeli has also treated the hypothesis in quite the same sense in his mechanico-physiological theory of descent (1884), and has represented it to be an indispensable thesis in any natural theory of evolution. I entirely agree with his assertion that “to reject abiogenesis is to admit a miracle.”
The hypothesis of spontaneous generation and the allied carbon-theory are of great importance in deciding the long-standing conflict between the teleological (dualistic) and the mechanical (monistic) interpretation of phenomena. Since Darwin gave us the key to the monistic explanation of organization in his theory of selection forty years ago, it has become possible for us to trace the splendid variety of orderly tendencies of the organic world to mechanical, natural causes, just as we could formerly in the inorganic world alone. Hence the supernatural and telic forces, to which the scientist had had recourse, have been rendered superfluous. Modern metaphysics, however, continues to regard the latter as indispensable and the former as inadequate.
No philosopher has done more than Immanuel Kant in defining the profound distinction between efficient and final causes, with relation to the interpretation of the whole cosmos. In his well-known earlier work on The General Natural History and Theory of the Heavens he made a bold attempt “to treat the constitution and the mechanical origin of the entire fabric of the universe according to Newtonian laws.” This “cosmological nebular theory” was based entirely on the mechanical phenomena of gravitation. It was expanded and mathematically established later on by Laplace. When the famous French astronomer was asked by Napoleon I. where God, the creator and sustainer of all things, came in in his system, he clearly and honestly replied: “Sire, I have managed without that hypothesis.” That indicated the atheistic character which this mechanical cosmogony shares with all the other inorganic sciences. This is the more noteworthy because the theory of Kant and Laplace is now almost universally accepted; every attempt to supersede it has failed. When atheism is denounced as a grave reproach, as it so often is, it is well to remember that the reproach extends to the whole of modern science, in so far as it gives a purely mechanical interpretation of the inorganic world.
Mechanicism (in the Kantian sense) alone can give us a true explanation of natural phenomena, for it traces them to their real efficient causes, to blind and unconscious agencies, which are determined in their action only by the material constitution of the bodies we are investigating. Kant himself emphatically affirms that “there can be no science without this mechanicism of nature,” and that the capacity of human reason to give a mechanical interpretation of phenomena is unlimited. But when he came subsequently to give an elucidation of the complex phenomena of organic nature in his critique of the teleological system, he declared that these mechanical causes were inadequate; that in this we must call final causes to our assistance. It is true, he said, that even here we must recognize the theoretical faculty of the mind to give a mechanical interpretation, but its actual competence to do so is restricted. He grants it this capacity to some extent; but for the majority of the vital processes (and especially for man’s psychic activity) he thinks we are bound to postulate final causes. The remarkable §79 of the critique of judgment bears the characteristic heading: “On the Necessity for the Subordination of the Mechanical Principle to the Teleological in the Explanation of a Thing as a Natural End.” It seemed to Kant so impossible to explain the orderly processes in the living organism without postulating supernatural final causes (that is, a purposive creative force) that he said: “It is quite certain that we cannot even satisfactorily understand, much less elucidate, the nature of an organism and its internal faculty on purely mechanical natural principles; it is so certain, indeed, that we may confidently say, ‘It is absurd for a man to conceive the idea even that some day a Newton will arise who can explain the origin of a single blade of grass by natural laws which are uncontrolled by design’—such a hope is entirely forbidden us.” Seventy years afterwards this impossible “Newton of the organic world” appeared in the person of Charles Darwin, and achieved the great task that Kant had deemed impracticable.
Since Newton (1682) formulated the law of gravitation, and Kant (1755) established “the constitution and mechanical origin of the entire fabric of the world on Newtonian laws,” and Laplace (1796) provided a mathematical foundation for this law of cosmic mechanicism, the whole of the inorganic sciences have become purely mechanical, and at the same time purely atheistic. Astronomy, cosmogony, geology, meteorology, and inorganic physics and chemistry are now absolutely ruled by mechanical laws on a mathematical foundation. The idea of “design” has wholly disappeared from this vast province of science. At the close of the nineteenth century, now that this monistic view has fought its way to general recognition, no scientist ever asks seriously of the “purpose” of any single phenomenon in the whole of this great field. Is any astronomer likely to inquire seriously to-day into the purpose of planetary motion, or a mineralogist to seek design in the structure of a crystal? Does the physicist investigate the purpose of electric force, or the chemist that of atomic weight? We may confidently answer in the negative—certainly not, in the sense that God, or a purposive natural force, had at some time created these fundamental laws of the mechanism of the universe with a definite design, and causes them to work daily in accordance with his rational will. The anthropomorphic notion of a deliberate architect and ruler of the world has gone forever from this field; the “eternal, iron laws of nature” have taken his place.
But the idea of design has a very great significance and application in the organic world. We do undeniably perceive a purpose in the structure and in the life of an organism. The plant and the animal seem to be controlled by a definite design in the combination of their several parts, just as clearly as we see in the machines which man invents and constructs; as long as life continues the functions of the several organs are directed to definite ends, just as is the operation of the various parts of a machine. Hence it was quite natural that the older naïve study of nature, in explaining the origin and activity of the living being, should postulate a creator who had “arranged all things with wisdom and understanding,” and had constructed each plant and animal according to the special purpose of its life. The conception of this “almighty creator of heaven and earth” was usually quite anthropomorphic; he created “everything after its kind.” As long as the creator seemed to man to be of human shape, to think with his brain, see with his eyes, and fashion with his hands, it was possible to form a definite picture of this “divine engineer” and his artistic work in the great workshop of creation. This was not so easy when the idea of God became refined, and man saw in his “invisible God” a creator without organs—a gaseous being. Still more unintelligible did these anthropomorphic ideas become when physiology substituted for the conscious, divine architect an unconscious, creative “vital force”—a mysterious, purposive, natural force, which differed from the familiar forces of physics and chemistry, and only took these in part, during life, into its service. This vitalism prevailed until about the middle of the nineteenth century. Johannes Müller, the great Berlin physiologist, was the first to menace it with a destructive dose of facts. It is true that the distinguished biologist had himself (like all others in the first half of the century) been educated in a belief in this vital force, and deemed it indispensable for an elucidation of the ultimate sources of life; nevertheless, in his classical and still unrivalled Manual of Physiology (1833) he gave a demonstrative proof that there is really nothing to be said for this vital force. Müller himself, in a long series of remarkable observations and experiments, showed that most of the vital processes in the human organism (and in the other animals) take place according to physical and chemical laws, and that many of them are capable of mathematical determination. That was no less true of the animal functions of the muscles and nerves, and of both the higher and the lower sense-organs, than of the vegetal functions of digestion, assimilation, and circulation. Only two branches of the life of the organism, mental action and reproduction, retained any element of mystery, and seemed inexplicable without assuming a vital force. But immediately after Müller’s death such important discoveries and advances were made in these two branches that the uneasy “phantom of vital force” was driven from its last refuge. By a very remarkable coincidence Johannes Müller died in the year 1858, which saw the publication of Darwin’s first communication concerning his famous theory. The theory of selection solved the great problem that had mastered Müller—the question of the origin of orderly arrangements from purely mechanical causes.
Darwin, as we have often said, had a twofold immortal merit in the field of philosophy—firstly, the reform of Lamarck’s theory of descent, and its establishment on the mass of facts accumulated in the course of the half-century; secondly, the conception of the theory of selection, which first revealed to us the true causes of the gradual formation of species. Darwin was the first to point out that the “struggle for life” is the unconscious regulator which controls the reciprocal action of heredity and adaptation in the gradual transformation of species; it is the great “selective divinity” which, by a purely “natural choice,” without preconceived design, creates new forms, just as selective man creates new types by an “artificial choice” with a definite design. That gave us the solution of the great philosophic problem: “How can purposive contrivances be produced by purely mechanical processes without design?” Kant held the problem to be insoluble, although Empedocles had pointed out the direction of the solution two thousand years before. His principle of “teleological mechanism” has become more and more accepted of late years, and has furnished a mechanical explanation even of the finest and most recondite processes of organic life by “the functional self-production of the purposive structure.” Thus have we got rid of the transcendental “design” of the ideological philosophy of the schools, which was the greatest obstacle to the growth of a rational and monistic conception of nature.
Very recently, however, this ancient phantom of a mystic vital force, which seemed to be effectually banished, has put in a fresh appearance; a number of distinguished biologists have attempted to reintroduce it under another name. The clearest presentation of it is to be found in the Welt als That, of the Kiel botanist, J. Reinke. He takes upon himself the defence of the notion of miracle, of theism, of the Mosaic story of creation, and of the constancy of species; he calls “vital forces,” in opposition to physical forces, the directive or dominant forces. Other neovitalists prefer, in the good old anthropomorphic style, a “supreme” engineer, who has endowed organic substance with a purposive structure, directed to the realization of a definite plan. These curious teleological hypotheses, and the objections to Darwinism which generally accompany them, do not call for serious scientific refutation to-day.
Thirty-three years ago I gave the title of “dysteleology” to the science of those extremely interesting and significant biological facts, which, in the most striking fashion, give a direct contradiction to the teleological idea “of the purposive arrangement of the living organism.”[30] This “science of rudimentary, abortive, arrested, distorted, atrophied, and cataplastic individuals” is based on an immense quantity of remarkable phenomena, which were long familiar to zoologists and botanists, but were not properly interpreted, and their great philosophic significance appreciated, until Darwin.
All the higher animals and plants, or, in general, all organisms which are not entirely simple in structure, but are made up of a number of organs in orderly co-operation, are found, on close examination, to possess a number of useless or inoperative members, sometimes, indeed, hurtful and dangerous. In the flowers of most plants we find, besides the actual sex-leaves that effect reproduction, a number of other leaf-organs which have no use or meaning (arrested or “miscarried” pistils, fruit, corona, and calix-leaves, etc.). In the two large and variegated classes of flying animals, birds and insects, there are, besides the forms which make constant use of their wings, a number of species which have undeveloped wings and cannot fly. In nearly every class of the higher animals which have eyes there are certain types that live in the dark; they have eyes, as a rule, but undeveloped and useless for vision. In our own human organism we have similar useless rudimentary structures in the muscles of the ear, in the eye-lid, in the nipple and milk-gland of the male, and in other parts of the body; indeed, the vermiform appendix of our cæcum is not only useless, but extremely dangerous, and inflammation of it is responsible for a number of deaths every year.
Neither the old mystic vitalism nor the new, equally irrational, neovitalism can give any explanation of these and many other purposeless contrivances in the structure of the plant and the animal; but they are very simple in the light of the theory of descent. It shows that these rudimentary organs are atrophied, owing to disuse. Just as our muscles, nerves, and organs of sense are strengthened by exercise and frequent use, so, on the other hand, they are liable to degenerate more or less by disuse or suspended exercise. But, although the development of the organs is promoted by exercise and adaptation, they by no means disappear without leaving a trace after neglect; the force of heredity retains them for many generations, and only permits their gradual disappearance after the lapse of a considerable time. The blind “struggle for existence between the organs” determines their historical disappearance, just as it effected their first origin and development. There is no internal “purpose” whatever in the drama.
The life of the animal and the plant bears the same universal character of incompleteness as the life of man. This is directly attributable to the circumstance that nature—organic as well as inorganic—is in a perennial state of evolution, change, and transformation. This evolution seems on the whole—at least as far as we can survey the development of organic life on our planet—to be a progressive improvement, an historical advance from the simple to the complex, the lower to the higher, the imperfect to the perfect. I have proved in my General Morphology that this historical progress—or gradual perfecting (teleosis)—is the inevitable result of selection, and not the outcome of a preconceived design. That is clear from the fact that no organism is perfect; even if it does perfectly adapt itself to its environment at a given moment, this condition would not last very long; the conditions of existence of the environment are themselves subject to perpetual change and they thus necessitate a continuous adaptation on the part of the organism.
Under the title of Design in the Living Organism, the famous embryologist, Karl Ernst Baer, published a work in 1876 which, together with the article on Darwinism which accompanied it, proved very acceptable to our opponents, and is still much quoted in opposition to evolution. It was a revival of the old teleological system under a new name, and we must devote a line of criticism to it. We must premise that, though Baer was a scientist of the highest order, his original monistic views were gradually marred by a tinge of mysticism with the advance of age, and he eventually became a thorough dualist. In his profound work on “the evolution of animals” (1828), which he himself entitled Observation and Experiment, these two methods of investigation are equally applied. By careful observation of the various phenomena of the development of the animal ovum Baer succeeded in giving the first consistent presentation of the remarkable changes which take place in the growth of the vertebrate from a simple egg-cell. At the same time he endeavored, by far-seeing comparison and keen reflection, to learn the causes of the transformation, and to reduce them to general constructive laws. He expressed the general result of his research in the following thesis: “The evolution of the individual is the story of the growth of individuality in every respect.” He meant that “the one great thought that controls all the different aspects of animal evolution is the same that gathered the scattered fragments of space into spheres and linked them into solar systems. This thought is no other than life itself, and the words and syllables in which it finds utterance are the varied forms of living things.”
Baer, however, did not attain to a deeper knowledge of this great genetic truth and a clearer insight into the real efficient causes of organic evolution, because his attention was exclusively given to one half of evolutionary science, the science of the evolution of the individual, embryology, or, in a wider sense, ontogeny. The other half, the science of the evolution of species, phylogeny, was not yet in existence, although Lamarck had already pointed out the way to it in 1809. When it was established by Darwin in 1859, the aged Baer was no longer in a position to appreciate it; the fruitless struggle which he led against the theory of selection clearly proved that he understood neither its real meaning nor its philosophic importance. Teleological and, subsequently, theological speculations had incapacitated the ageing scientist from appreciating this greatest reform of biology. The teleological observations which he published against it in his Species and Studies in his eighty-fourth year are mere repetitions of errors which the teleology of the dualists has opposed to the mechanical or monistic system for more than two thousand years. The “telic idea” which, according to Baer, controls the entire evolution of the animal from the ovum, is only another expression for the eternal “idea” of Plato and the entelecheia of his pupil Aristotle.
Our modern biogeny gives a purely physiological explanation of the facts of embryology, in assigning the functions of heredity and adaptation as their causes. The great biogenetic law, which Baer failed to appreciate, reveals the intimate causal connection between the ontogenesis of the individual and the phylogenesis of its ancestors; the former seems to be a recapitulation of the latter. Nowhere, however, in the evolution of animals and plants do we find any trace of design, but merely the inevitable outcome of the struggle for existence, the blind controller, instead of the provident God, that effects the changes of organic forms by a mutual action of the laws of heredity and adaptation. And there is no more trace of “design” in the embryology of the individual plant, animal, or man. This ontogeny is but a brief epitome of phylogeny, an abbreviated and condensed recapitulation of it, determined by the physiological laws of heredity.
Baer ended the preface to his classical Evolution of Animals (1828) with these words: “The palm will be awarded to the fortunate scientist who succeeds in reducing the constructive forces of the animal body to the general forces or life-processes of the entire world. The tree has not yet been planted which is to make his cradle.” The great embryologist erred once more. That very year, 1828, witnessed the arrival of Charles Darwin at Cambridge University (for the purpose of studying theology!)—the “fortunate scientist” who richly earned the palm thirty years afterwards by his theory of selection.
In the philosophy of history—that is, in the general reflections which historians make on the destinies of nations and the complicated course of political evolution—there still prevails the notion of a “moral order of the universe.” Historians seek in the vivid drama of history a leading design, an ideal purpose, which has ordained one or other race or state to a special triumph, and to dominion over the others. This teleological view of history has recently become more strongly contrasted with our monistic view in proportion as monism has proved to be the only possible interpretation of inorganic nature. Throughout the whole of astronomy, geology, physics, and chemistry there is no question to-day of a “moral order,” or a personal God, whose “hand hath disposed all things in wisdom and understanding.” And the same must be said of the entire field of biology, the whole constitution and history of organic nature, if we set aside the question of man for the moment. Darwin has not only proved by his theory of selection that the orderly processes in the life and structure of animals and plants have arisen by mechanical laws without any preconceived design, but he has shown us in the “struggle for life” the powerful natural force which has exerted supreme control over the entire course of organic evolution for millions of years. It may be said that the struggle for life is the “survival of the fittest” or the “victory of the best”; that is only correct when we regard the strongest as the best (in a moral sense). Moreover, the whole history of the organic world goes to prove that, besides the predominant advance towards perfection, there are at all times cases of retrogression to lower stages. Even Baer’s notion of “design” has no moral feature whatever.
Do we find a different state of things in the history of peoples, which man, in his anthropocentric presumption, loves to call “the history of the world”? Do we find in every phase of it a lofty moral principle or a wise ruler, guiding the destinies of nations? There can be but one answer in the present advanced stage of natural and human history: No. The fate of those branches of the human family, those nations and races which have struggled for existence and progress for thousands of years, is determined by the same “eternal laws of iron” as the history of the whole organic world which has peopled the earth for millions of years.
Geologists distinguish three great epochs in the organic history of the earth, as far as we can read it in the monuments of the science of fossils—the primary, secondary, and tertiary epochs. According to a recent calculation, the first occupied at least thirty-four million, the second eleven million, and the third three million years. The history of the family of vertebrates, from which our own race has sprung, unfolds clearly before our eyes during this long period. Three different stages in the evolution of the vertebrate correspond to the three epochs; the fishes characterized the primary (palæozoic) age, the reptiles the secondary (mesozoic), and the mammals the tertiary (cænozoic). Of the three groups the fishes rank lowest in organization, the reptiles come next, and the mammals take the highest place. We find, on nearer examination of the history of the three classes, that their various orders and families also advanced progressively during the three epochs towards a higher stage of perfection. May we consider this progressive development as the outcome of a conscious design or a moral order of the universe? Certainly not. The theory of selection teaches us that this organic progress, like the earlier organic differentiation, is an inevitable consequence of the struggle for existence. Thousands of beautiful and remarkable species of animals and plants have perished during those forty-eight million years, to give place to stronger competitors, and the victors in this struggle for life were not always the noblest or most perfect forms in a moral sense.