This combination was accomplished by Fritz Muller. He thereby brought the earlier forms of an animal cla.s.s into a certain law-determined connection with the later ones, which, through transformation, have formed out of them. The fact that at an earlier stage the ancestral form of a being now living has had a particular form caused its descendants at a later time to have another particular form. By studying the stages of the development of an organism one becomes acquainted with its ancestors whose nature has caused the characteristics of the embryonic forms. Phylogenesis and ontogenesis are, in Fritz Muller"s book, connected as cause and effect. With this step a new element had entered the Darwinian trend of ideas.
This fact retains its significance even though Muller"s investigations of the crustaceans were modified by the later research of Arnold Lang.
Only four years had pa.s.sed since the appearance of Darwin"s Origin of the Species when Muller"s book was published as its defense and confirmation. Muller had shown how, with one special cla.s.s of animals, one should work in the spirit of the new ideas. Then, in 1866, seven years after the Origin of the Species, a book appeared that completely absorbed this new spirit. Using the ideas of Darwinism on a high level of scientific discussion, it threw a great deal of light on the problems of the interconnection of all life phenomena. This book was Ernst Haeckel"s General Morphology of Organisms.
Every page reflected his attempt to arrive at a comprehensive
synopsis of the totality of the phenomena of nature with the help of new thoughts. Inspired by Darwinism, Haeckel was in search of a world conception.
Haeckel did his best in two ways to attempt a new world conception. First, he continually contributed to the acc.u.mulation of facts that throw light on the connection of the ent.i.ties and energies of nature. Second, with unbending consistency he derived from these facts the ideas that were to satisfy the human need for explanation. He held the unshakable conviction that from these facts and ideas man can arrive at a fully satisfactory world explanation. Like Goethe, Haeckel was convinced in his own way that nature proceeds in its work "according to eternal, necessary and thereby divine laws, so that not even the deity could change it." Because this was clear to him, he worshipped his deity in these eternal and necessary laws of nature and in the substances in which they worked. As the harmony of the natural laws, which are with necessity interconnected, satisfies reason, according to his view, so it also offers to the feeling heart, or to the soul that is ethically or religiously attuned, whatever it may thirst for. In the stone that falls to the ground attracted by gravity there is a manifestation of the same divine order that is expressed in the blossom of a plant and in the human spirit that created the drama of Wilhelm Tell.
How erroneous is the belief that the feeling for the wonderful beauty of nature is destroyed by the penetration of reason into laws of nature is vividly demonstrated in the work of Ernst Haeckel. A rational explanation of nature had been declared to be incapable of satisfying the needs of the soul. Wherever man is disturbed in his inner life through knowledge of nature, it is not the fault of knowledge but of man himself. His sentiments are developed in a wrong direction. As we follow a naturalist like Haeckel without prejudice on his path as an
observer of nature, we feel our hearts beat faster. The anatomical a.n.a.lysis, the microscopic investigation does not detract from natural beauty but reveals a great deal more of it.
There is no doubt that there is an antagonism between reason and imagination, between reflection and intuition, in our time. The brilliant essayist, Ellen Key, is without doubt right in considering this antagonism as one of the most important phenomena of our time (compare Ellen Key, Essays, S.
Fischer Verlag, Berlin, 1899). Whoever, like Ernst Haeckel, digs deep into the treasure mine of facts, boldly emerges with the thoughts resulting from these facts and climbs to the heights of human knowledge, can see in the explanation of nature only an act of reconciliation between the two contesting forces of reflection and intuition that "alternate in forcing each other into submission" (Ellen Key). Almost simultaneously with the publication of the book in which Haeckel presented with unflinching intellectual honesty his world conception derived from natural science, that is, with the appearance of his Riddles of the Universe in 1899, he began a serial publication called Artforms of Nature. In it he gives pictures of the inexhaustible wealth of wonderful formations that nature produces and that surpa.s.s "by far all artistic forms created by man" in beauty and in variety. The same man who introduces our mind to the law-determined order of nature leads our imagination to the beauty of nature.
The need to bring the great problems of world conception into direct contact with scientific, specialized research led Haeckel to one of the facts concerning which Goethe said that they represent the significant points at which nature yields the fundamental ideas for its explanation of its own accord, meeting us halfway in our search. This was realized by Haeckel as he investigated how Oken"s thesis, which Fritz Muller had applied to the crustaceans, could be fruitfully applied to the whole animal kingdom. In all animals except
the Protista, which are one-celled organisms, a cup- or jug- shaped body, the gastrula, develops from the zygote with which the organism begins its ontogenesis. This gastrula is an animal form that is to be found in the first stages of development of all animals from the sponges to man. It consists merely of skin, mouth and stomach. There is a low cla.s.s of zoophytes that possess only these organs during their lives and therefore resemble gastrulae. This fact is interpreted by Haeckel from the point of view of the theory of descent.
The gastrula form is an inherited form that the animal owes to the form of its common ancestor. There had been, probably millions of years before, a species of animals, the gastrae, that was built in a way similar to that of the lower zoophytes still living today - the sponges, polyps, etc. From this animal species all the various forms living today, from the polyps, sponges, etc., to man, repeat this original form in the course of their ontogenies.
In this way an idea of gigantic scope had been obtained. The path leading from the simple to the complicated, to the perfect form in the world of organisms, was thereby indicated in its tentative outline. A simple animal form develops under certain circ.u.mstances. One or several individuals of this form change to another form according to the conditions of life to which they are exposed. What has come into existence through this trans.m.u.tation is again transmitted to descendants. There are then two different forms, the old one that has retained the form of the first stage, and a new one.
Both of these forms can develop in different directions and into different degrees of perfection. After long periods of time an abundant wealth of species comes into existence through the transmission of the earlier form and through new formations by means of the process of adaptation to the conditions of life.
In this manner Haeckel connects today"s processes in the world of organisms with the events of primeval times. If we want to explain some organ of an animal of the present age, we look back to the ancestors that had developed this organ under the circ.u.mstances in which they lived. What has come into existence through natural causes in earlier times has been handed down to our time through the process of heredity.
Through the history of the species the evolution of the individual receives its explanation. The phylogenesis, therefore, contains the causes for the ontogenesis. Haeckel expresses this fact in his fundamental law of biogenetics: "The short ontogenesis or development of the individual is a rapid and brief repet.i.tion, an abbreviated recapitulation of the long process of phylogenesis, the development of the species."
Through this law every attempt at explanation through special purposes, all teleology in the old sense, has been eliminated.
One no longer looks for the purpose of an organ; one looks for the causes through which it has developed. A given form does not point to a goal toward which it strives, but toward the origin from which it sprang. The method of explanation for the organic phenomena has become the same as that for the inorganic. Water is not considered the aim of oxygen, nor is man considered the purpose of creation. Scientific research is directed toward the origin of, and the actual cause for, living beings. The dualistic mode of conception, which declares that the organic and the inorganic has to be explained according to two different principles, gives way to a monistic mode of conception, to a monism that has only one uniform mode of explanation for the whole of nature.
Haeckel characteristically points out that through his discovery the method has been found through which every dualism in the above-mentioned sense must be overcome.
Phylogenesis is the mechanical cause of ontogenesis. With this statement our basically monistic conception of organic evolution is clearly characterized, and on the truth of this principle depends primarily the truth of the gastraea theory. . .
. Every naturalist, who in the field of biogenesis is not satisfied with a mere admiration of strange phenomena but strives for an understanding of their significance, will, in the future, either have to side with or against this principle. It marks at the same time the complete break that separates the older teleological and dualistic morphology from the new mechanical and monistic one. If the physiological functions of inheritance and adaptation have been proven to be the only causes of the process of organic formation, then every kind of teleology, of dualistic and metaphysical mode of conception has thereby been eliminated from the field of biogenesis; the sharp contrast between the leading principles is clearly marked. Either a direct and causal connection between ontogeny and phylogeny exists or it does not. There is no third possibility! Either epigenesis and descent, or pre-formation and creation! (Compare also in Part 1 Chapter IX of this book.) After Haeckel had absorbed Darwin"s view of the origin of man he defended forcefully the conclusion that must be drawn from it. It was impossible for him just to hint hesitatingly, like Darwin, at this "problem of all problems." Anatomically and physiologically man is not distinguishable from the higher animals. Therefore, the same origin must be attributed to him as to them. Haeckel boldly defended this opinion and the consequences that followed from it for the conception of the world. There was no doubt for him that in the future the highest manifestations of man"s life, the activities of his spirit, were to be considered under the same viewpoint as the function of the simplest living organism. The observation of the lowest animals, the protozoa, infusoria, rhizopods, taught
him that these organisms had a soul. In their motions, in the indications of the sensations they show, he recognized manifestations of life that only had to be increased and perfected in order to develop into man"s complicated actions of reason and will.
Beginning with the gastraea, which lived millions of years ago, what steps does nature take to arrive at man? This was the comprehensive question as stated by Haeckel. He supplied the answer in his Anthropogenesis, which appeared in 1874. In its first part, this book deals with the history of the individual (ontogenesis), in the second part, with that of the species (phylogenesis). He showed point by point how the latter contains the causes of the former. Man"s position in nature had thereby been determined according to the principles of the theory of descent. To works like Haeckel"s Anthropogenesis, the statement that the great anatomist, Karl Gegenbaur, made in his Comparative Anatomy (1870) can be justly applied. He wrote that in exchange for the method of investigation Darwin gave to science with his theory he received in return clarity and firmness of purpose. In Haeckel"s view, the method of Darwinism had also supplied science with the theory of the origin of man.
What actually was accomplished by this step can be appreciated in its full measure only if one looks at the opposition with which Haeckel"s comprehensive application of the principles of Darwinism was received by the followers of idealistic world conceptions. It is not even necessary to quote those who, blindly believing in the traditional opinion, turned against the "monkey theory," or those who believed that all finer, higher morality would be endangered if men were no longer convinced that they had a "purer, higher origin." Other thinkers, although quite open-minded with regard to new truths, found it difficult to accept this new truth. They asked themselves the question, "Do we not deny our own rational
thinking if we no longer look for its origin in a general world reason over us, but in the animal kingdom below?"
Mentalities of this sort eagerly attacked the points where Haeckel"s view seemed to be without support of the facts. They had powerful allies in a number of natural scientists who, through a strange bias, used their factual knowledge to emphasize the points where actual experience was still insufficient to prove the conclusions drawn by Haeckel. The typical, and at the same time the most impressive, representative of this viewpoint of the naturalists was Rudolf Virchow (1821 1902). The opposition of Virchow and Haeckel can be characterized as follows. Haeckel puts his trust in the inner consistency of nature, concerning which Goethe is of the opinion that it is sufficient to make up for man"s inconsistency. Haeckel, therefore, argues that if a principle of nature has been verified for certain cases, and if we still lack the experience to show its validity in other cases, we have no reason to hold the progress of our knowledge back. What experience denies us today, it may yield tomorrow. Virchow is of the opposite opinion. He wants to yield as little ground as possible to a comprehensive principle. He seems to believe that life for such a principle cannot be made hard enough. The antagonism between these two spirits was brought to a sharp point at the Fiftieth Congress of German naturalists and doctors in 1877. Haeckel read a paper there on the topic, The Theory of Evolution of Today in Its Relation to Science in General.
In 1894 Virchow felt that he had to state his view in the following way. "Through speculation one has arrived at the monkey theory; one could just as well have ended up with an elephant theory or a sheep theory." What Virchow demanded was incontestable proof of this theory. As soon as something turned up that fitted as a link in the chain of the argumentation, Virchow attempted to invalidate it with all
means at his disposal.
Such a link in the chain of proof was presented with the bone remnants that Eugen Dubois had found in Java in 1894. They consisted of a skull and thigh bone and several teeth.
Concerning this find, an interesting discussion arose at the Congress of Zoologists at Leyden. Of twelve zoologists, three were of the opinion that these bones came from a monkey and three thought they came from a human being; six, however, believed they presented a transitional form between man and monkey. Dubois shows in a convincing manner in what relation the being whose bone remnants were under discussion stood to the present monkey, on the one hand, and to man of today, on the other. The theory of evolution of natural science must claim such intermediary forms. They fill the holes that exist between numerous forms of organisms.
Every new intermediary form const.i.tutes a new proof for the kinship of all living organisms. Virchow objected to the view that these bone remnants came from such an intermediary form. At first, he declared that it was the skull of a monkey and the thigh bone of a man. Expert paleontologists, however, firmly p.r.o.nounced, according to the careful report, on the finding, that the remnants belonged together. Virchow attempted to support his view that the thigh bone could be only that of a human being with the statement that a certain growth in the bone proved that it must have had a disease that could only have been healed through careful human attention.
The paleontologist, Marsch, [e.Ed: perhaps American paleontologist, Othniel Charles Marsh (1831 1899)]
however, maintained that similar bone extuberances occurred in wild animals as well. A further statement of Virchow"s, that the deep incision between the upper rim of the eye socket and the lower skull cover of the alleged intermediary form proved it to be the skull of a monkey was then contradicted by the naturalist Nehring, who claimed that the same formation was
found in a human skull from Santos, Brazil. Virchow"s objections came from the same turn of mind that also caused him to consider the famous skulls of Neanderthal, Spy, etc., as pathological formations, while Haeckel"s followers regarded them as intermediary forms between monkey and man.
Haeckel did not allow any objections to deprive him of his confidence in his mode of conception. He continued his scientific work without swerving from the viewpoints at which he had arrived, and through popular presentations of his conception of nature, he influenced the public consciousness.
In his book, Systematic Phylogenesis, Outline of a Natural System of Organisms on the Basis of the History of Species (1894 96), he attempted to demonstrate the natural kinship of organisms in a strictly scientific method. In his Natural History of Creation, which, from 1868 1908, appeared in eleven editions, he gave a popular explanation of his views. In 1899, in his popular studies on monistic philosophy ent.i.tled, The Riddles of the Universe, he gave a survey of his ideas in natural philosophy by demonstrating without reserve the many applications of his basic thoughts. Between all these works he published studies on the most diverse specialized researches, always paying attention at the same time to the philosophical principles and the scientific knowledge of details.
The light that shines out from the monistic world conception is, according to Haeckel"s conviction, to "disperse the heavy clouds of ignorance and superst.i.tion that have heretofore spread an impenetrable darkness over the most important one of all problems of human knowledge, that is, the problem concerning man"s origin, his true nature and his position in nature." This is what he said in a speech given August 26, 1898 at the Fourth International Congress of Zoologists in Cambridge, On Our Present Knowledge Concerning the Origin of Man. In what respect his world conception forms a
bond between religion and science, Haeckel has shown in an impressive way in his book, Monism as a Bond between Religion and Science, Credo of a Naturalist, which appeared in 1892.
If one compares Haeckel with Hegel, one can see distinctly the difference in the tendencies of world conception in the two halves of the nineteenth century. Hegel lives completely in the idea and accepts only as much as he needs from the world of facts for the ill.u.s.tration of his idealistic world picture. Haeckel is rooted with every fiber of his being in the world of facts, and he derives from this world only those ideas toward which these facts necessarily tend. Hegel always attempts to show that all beings tend to reach their climax of evolution in the human spirit; Haeckel continuously endeavors to prove that the most complicated human activities point back to the simplest origins of existence. Hegel explains nature from the spirit; Haeckel derives the spirit from nature. We can, therefore, speak of a reversal of the thought direction in the course of the century. Within German intellectual life, Strauss, Feuerbach and others began this process of reversal. In their materialism the new direction found a provisional extreme expression, and in Haeckel"s thought world it found a strictly methodical-scientific one. For this is the significant thing in Haeckel, that all his activity as a research worker is permeated by a philosophical spirit. He does not at all work toward results that for some philosophical motivation or other are considered to be the aim of his world conception or of his philosophical thinking. What is philosophical about him is his method. For him, science itself has the character of a world conception. His very way of looking at things predestines him to be a monist. He looks upon spirit and nature with equal love. For this reason he could find spirit in the simplest organism. He goes even further than that. He looks for the traces of spirit in the inorganic particles of matter:
Every atom possesses an inherent quant.i.ty of energy and in this sense is animate. Without a.s.suming a soul for the atom, the simplest and most general phenomena of chemistry are unexplainable. Pleasure and displeasure, desire and aversion, attraction and repulsion must be a common property of all material atoms. For the motion of the atoms, which must take place in the formation and dissolution of every chemical compound can only be explained if we a.s.sume that they have sensation and will. On this a.s.sumption the generally accepted chemical doctrine of affinity is really based.
As he traces spirit down to the atom so he follows the purely material mechanism of events up to the most lofty accomplishments of the spirit: The spirit and soul of man are also nothing else but energies that are inseparably bound to the material substratum of our bodies. As the motion of our flesh is bound to the form elements of our muscles, so our mind"s power of thinking is bound to the form elements of our brains. Our spiritual energies are simply functions of these physical organs just as every energy is a function of a material body.
One must not confuse this mode of conception with one that dreams souls in a hazy mystical fashion into the ent.i.ties of nature and then a.s.sumes that they are more or less similar to that of man. Haeckel is a strict opponent of a world conception that projects qualities and activities of man into the external world. He has repeatedly expressed his condemnation of the humanization of nature, of anthropomorphism, with a clarity that cannot be misunderstood. If he attributes animation to inorganic matter, or to the simplest organisms, he means by that nothing more than the sum of energy manifestations that we observe in them. He holds strictly to the facts. Sensation and will are for him no mystical soul energies but are nothing more than.
what we observe as attraction and repulsion. He does not mean to say that attraction and repulsion are really sensation and will. What he means is that attraction and repulsion are on the lowest stage what sensation and will are on a higher one. For evolution is for him not merely an unwrapping of the higher stages of the spiritual out of the lower forms in which they are already contained in a hidden fashion, but a real ascent to new formations, an intensification of attraction and repulsion into sensation and will (compare prior comments in this Chapter).
This fundamental view of Haeckel agrees in a certain way with that of Goethe. He states in this connection that he had arrived at the fulfillment of his view of nature with his insight into the "two great springs of all nature," namely, polarity and intensification (Polaritat und Steigerung), polarity "belonging to matter insofar as we think of it materially, intensification insofar as we think of it spiritually. The former is engaged in the everlasting process of attraction and repulsion, the latter in a continual intensification. As matter can never be and act without spirit, however, nor spirit without matter, so matter can also be intensified and the spirit will never be without attraction and repulsion."
A thinker who believes in such a world conception is satisfied to explain by other such things and processes, the things and processes that are actually in the world. The idealistic world conceptions need, for the derivation of a thing or process, ent.i.ties that cannot be found within the realm of the factual.
Haeckel derives the form of the gastrula that occurs in the course of animal evolution from an organism that he a.s.sumes really existed at some time. An idealist would look for ideal forces under the influence of which the developing germ becomes the gastrula. Haeckel"s monism draws everything he needs for the explanation of the real world from the same real world. He looks around in the world of the real in order to
recognize in which way the things and processes explain one another. His theories do not have the purpose for him, as do those of the idealist, to find a higher element in addition to the factual elements, but they merely serve to make the connection of the facts understandable. Fichte, the idealist, asked the question of man"s destination. He meant by that something that cannot be completely presented in the form of the real, the factual; something that reason has to produce as an addition to the factually given existence, an element that is to make the real existence of man translucent by showing it in a higher light. Haeckel, the monistic contemplator of the world, asks for the origin of man, and he means by that the factual origin, the lower organism out of which man had developed through actual processes.
It is characteristic that Haeckel argues for the animation of the lower organisms. An idealist would have resorted to rational conclusions. He would present necessities of thought.
Haeckel refers to what he has seen.
Every naturalist, who, like me, has observed for many years the life activities of the one-celled protozoa, is positively convinced that they, too, possess a soul. This cellular soul consists also of a sum of sensations, perceptions and will activities; sensation, thinking and will of our human souls differ from those of the cellular soul only in degree.
The idealist attributes spirit to matter because he cannot accept the thought that spirit can develop from mere matter.
He believes that one would have to deny the spirit if one does not a.s.sume it to exist before its appearance in forms of existence without organs, without brains. For the monist, such thoughts are not possible. He does not speak of an existence that is not manifested externally as such. He does not attribute two kinds of properties to things: those that are real and manifested in them and those that in a hidden way are
latent in them only to be revealed at a higher stage of development. For him, there is what he observes, nothing else, and if the object of observation continues its evolution and reaches a higher stage in the course of its development, then these later forms are there only in the moment when they become visible.
How easily Haeckel"s monism can be misunderstood in this direction is shown by the objections that were made by the brilliant thinker, Bartholomaeus von Carneri (1821 1909), who made lasting contributions for the construction of an ethics of this world conception. In his book, Sensations and Consciousness, Doubts Concerning Monism (1893), he remarks that the principle, "No spirit without matter, but also no matter without spirit," would justify our extending this question to the plant and even to the next rock we may stumble against, and to attribute spirit also to them. Without doubt such a conclusion would lead to a confusion of distinctions. It should not be overlooked that consciousness arises only through the cell activity in the cerebrum. "The conviction that there is no spirit without matter, that is to say, that all spiritual activity is bound to a material activity, the former terminating with the latter, is based on experience, while there is no experience for the statement that there is always spirit connected with matter." Somebody who would want to attribute animation to matter that does not show any trace of spirit would be like one who attributed the function to indicate time not to the mechanism of a watch but to the metal out of which it is made.
Properly understood, Haeckel"s view is not touched by Carneri"s criticism. It is safe from this criticism because Haeckel holds himself strictly within the bounds of observation. In his Riddles of the Universe, he says, "I, myself, have never defended the theory of atom-consciousness. I have, on the contrary, expressly emphasized that I think the
elementary psychic activities of sensation and will, which are attributed to the atoms, as unconscious." What Haeckel wants is only that one should not allow a break in the explanation of natural phenomena. He insists that one should trace back the complicated mechanism by which spirit appears in the brain, to the simple process of attraction and repulsion of matter.
Haeckel considers the discovery of the organs of thought by Paul Flechsig to be one of the most important accomplishments of modern times. Flechsig had pointed out that in the gray matter of the brain there are to be found the four seats of the central sense organs, or four "inner spheres of sensation," the spheres of touch, smell, sight and hearing.
"Between the sense centers lie thought centers, the "real organs of mental life." They are the highest organs of psychic activity that produce thought and consciousness. . . . These four thought centers, distinguished from the intermediate sense centers by a peculiar and highly elaborate nerve structure, are the true organs of thought, the only organs of our consciousness. Recently, Flechsig has proved that man has some especially complicated structures in some of these organs that cannot be found in the other mammals and that explain the superiority of human consciousness." (Riddles of the Universe, Chapt. X.) Pa.s.sages like these show clearly enough that Haeckel does not intend to a.s.sume, like the idealistic philosophers, the spirit as implicitly contained in the lower stages of material existence in order to be able to find it again on the higher stages. What he wanted to do was to follow the simplest phenomena to the most complicated ones in his observation, in order to show how the activity of matter, which in the most primitive form is manifested in attraction and repulsion, is intensified in the higher mental operations.
Haeckel does not look for a general spiritual principle for lack of adequate general laws explaining the phenomena of nature and mind. So far as his need is concerned, his general law is indeed perfectly sufficient. The law that is manifested in the mental activities seems to him to be of the same kind as the one that is apparent in the attraction and repulsion of material particles. If he calls atoms animated, this has not the same meaning that it would have if a believer in an idealistic world conception did so. The latter would proceed from the spirit.
He would take the conceptions derived from the contemplation of the spirit down into the simplest functions of the atoms when he thinks of them as animated. He would explain thereby the natural phenomena from ent.i.ties that he had first projected into them. Haeckel proceeds from the contemplation of the simplest phenomena of nature and follows them up to the highest spiritual activities. This means that he explains the spiritual phenomena from laws that he has observed in the simplest natural phenomena.
Haeckel"s world picture can take shape in a mind whose observation extends exclusively to natural processes and natural ent.i.ties. A mind of this kind will want to understand the connection within the realm of these events and beings.
His ideal would be to see what the processes and beings themselves reveal with respect to their development and interaction, and to reject rigorously everything that might be added in order to obtain an explanation of these processes and activities. For such an ideal one is to approach all nature as one would, for instance, proceed in explaining the mechanism of a watch. It is quite unnecessary to know anything about the watchmaker, about his skill and about his thoughts, if one gains an insight into the mechanical actions of its parts. In obtaining this insight one has, within certain limits, done everything that is admissible for the explanation of the operation of the watch. One ought to be clear about the fact
that the watch itself cannot be explained if another method of explanation is admitted, as, for instance, if somebody thought of some special spiritual forces that move the hour and minute hands according to the course of the sun. Every suggestion of a special life force, or of a power that works toward a "purpose" within the organisms, appears to Haeckel as an invented force that is added to the natural processes. He is unwilling to think about the natural processes in any other way than by what they themselves disclose to observation. His thought structure is to be derived directly from nature.
In observing the evolution of world conception, this thought structure strikes us, as it were, as the counter-gift from the side of natural science to the Hegelian world conception, which accepts in its thought picture nothing from nature but wants everything to originate from the soul. If Hegel"s world conception said that the self-conscious ego finds itself in the experience of pure thought, Haeckel"s view of nature could reply that the thought experience is a result of the nature processes, is, indeed, their highest product. If the Hegelian world conception would not be satisfied with such a reply, Haeckel"s naturalistic view could demand to be shown some inner thought experience that does not appear as if it were a mirror reflection of events outside thought life. In answer to this demand, a philosophy would have to show how thought can come to life in the soul and can really produce a world that is not merely the intellectual shadow of the external world. A thought that is merely thought, merely the product of thinking, cannot be used as an effective objection to Haeckel"s view. In the comparison mentioned above, he would maintain that the watch contains nothing in itself that allows a conclusion as to the personality, etc., of the watchmaker.
Haeckel"s naturalistic view tends to show that, as long as one is merely confronted with nature, one cannot make any statement concerning nature except what it records. In this
respect this naturalistic conception is significant as it appears in the course of the development of world conception. It proves that philosophy must create a field for itself that lies in the realm of spontaneous creativity of thought life beyond the thoughts that are gained from nature.
Philosophy must take the step beyond Hegel that was pointed out in a previous chapter. It cannot consist of a method that moves in the same field with natural science. Haeckel himself probably felt not the slightest need to pay any attention to such a step of philosophy. His world conception does bring thoughts to life in the soul, but only insofar as their life has been stimulated by the observation of natural processes. The world picture that thought can create when it comes to life in the soul without this stimulus represents the kind of higher world conception that would adequately complement Haeckel"s picture of nature. One has to go beyond the facts that are directly contained in the watch if one wants to know, for instance, something about the form of the watchmaker"s face. But, for this reason, one has no right to demand that Haeckel"s naturalistic view itself should not speak as Haeckel does when he states what positive facts he has observed concerning natural processes and natural beings.
Chapter III.
The World as Illusion
Besides the current of world conception that, through the idea of evolution, wants to bring the conception of the phenomena of nature and that of the spirit into complete unity, there is another that expresses their opposition in the strongest possible form. This current also springs from natural science.
Its followers ask, "What is our basis as we construct a world conception by means of thinking? We hear, see and touch the physical world through our senses. We then think about the facts that our senses supply concerning that world. We form our thoughts accordingly concerning the world at the testimony of the senses. But are the statements of our senses really to be trusted?"
Let us consult actual observations. The eye conveys to us the phenomena of light. We say an object sends us red light when the eye has the sensation of red. But the eye conveys sensations of light to us also in other cases. When it is pushed or pressed, or when an electric current flows through our head, the eye also has sensations of light. It is, therefore, possible that in cases in which we have the sensation of a light-sending body, something could go on in that object that has no semblance to our sensation of light. The eye, nevertheless, would transmit light to us.
The physiologist, Johannes Mueller (1801 58), drew the conclusion from these facts that what man has as his actual sensation does not depend on the external processes but on his organization. Our nerves transmit sensations to us. As we do not have the sensation of the knife that cuts us but a state of our nerves that appears to us as pain, so we also do not