The History of Biological Theories

This attempt to 'prove', to analyse logically ; this con- stant striving for accuracy of inference ; this 'intoxication of thought' for which Lotze was once reproached all these render the works of Driesch almost unapproachable. In his theoretical work Driesch was a follower of Roux and Weismann. They, too, believed that it is extremely important that every assertion should be logically 'proved'. But Weismann's logic consisted chiefly of ingenious de- ductions from hypotheses which have very little contact with reality, and are meant for the reader rather than for the author himself. Roux's work took the form of a dull and extremely specialized science, but Driesch broke away from this tradition. He endeavours to prove each of his statements to his own satisfaction, and is willing to take into consideration not only biological facts but also the opinions of philosophers.

Driesch left biology before the war, and became a philosopher. As such he is related to Kant. Like Kant, Driesch is endeavouring to formulate a pure and un- assailable natural science a science containing only pro- positions which are of universal application, and hence a science which will rise above every form of doubt. Driesch believes that he can attain to this by examining the most fundamental logical principles. This was the aim of his book on Ordnungslebre und Wirklichkeitslehre. He was endeavouring to formulate axioms which would ex- press the most general laws of natural science.

Driesch sought to go further than Kant, who had been accused of taking his categories (quantity, quality, rela- tion, and modality) from earlier authors without first proving that they were logically necessary. Further, Kant's illogical attitude to subjective ideas had been severely criticized. Driesch attempted to correct these errors and make good these omissions. The categories are not merely to be thought of as indissolubly bound up with a subject, as necessarily part of an ego, of which they represent the qualities. They are more fundamental than this. The ego itself is the result of categorical thought, while the cate- gories themselves are the result of experience in its most generalized and extensive form. They are not inductions from experience, as so many English writers assert ; but neither do they represent principles which precede all experience. They are first awakened by experience ; it is then that we call them to mind, the experience providing, as it were, the opportunity. Hence Kant's discussion of the application of the categories to facts beyond experi- ence and his formulation of a 'Thing in itself are illusory.

Kant's treatment of categories formed the starting-point of the speculations of the Romantic philosophers. Fichte and Schelling, however, abandoned the formal, analytical methods of their master. Fichte asserted that logic is not a real science. It has for its subject-matter the processes of thought, and hence it merely subjects to analysis the real knowledge whose existence it must assume. Driesch, on the other hand, elaborated the formal and logical aspect of Kant's philosophy first of all.

Driesch paid special attention to the philosophies of Hegel, Schopenhauer, and E. von Hartmann, as well as to the views of Kant ; to Hegel because he emphasized abstract logic; to Schopenhauer and Hartmann because they assumed that the will is the cause of all action. Fichte and Schelling, on the other hand, have had no influence upon Driesch, for they did not adopt these analytical methods. Driesch did not follow the bad habits of most biologists, who look upon physics and chemistry as fixed and concrete sciences, whose conclusions they must simply accept. He examined the logical bases of these studies, criticized them, and compared their methods with the logical methods of the biological sciences. Thus he hoped to get a clearer picture of the whole problem. 1

Others had assumed that the great difference between physics and biology was that the former science deals with general laws (the laws of refraction, Coulomb's law, Galileo's laws of falling bodies), while the biological sciences describe actual concrete objects, e.g. a horse or a rose. Driesch did not acknowledge this difference. Biologists in his view must also formulate reasoned conceptions which are of general application. Such conceptions as cells, chromosomes, vertebrates are not rational concep- tions, but collective conceptions, analogous to the physical conceptions of heat and cold, and are arrived at by simple abstraction from separate facts. The rational and only really scientific conceptions, on the other hand, are in- tellectual ones, like those physical concepts of velocity, acceleration, and refractive indices, which the physicist has devised for the purpose of understanding events. In their methods, then, physics and biology are alike, but their objects are fundamentally different, for the latter is con- cerned with life, and life is governed by laws which are not the laws which govern the inanimate world.

Descriptive natural history gives us concrete events, as if these were the ultimate realities it presents those events in the final form into which they have been moulded. Each fact, each event, is regarded as something 1 Driesch discusses the relation between biology and other sciences most exhaustively in Naturbegrijfe und Natururtcile, 1904. absolute ; but the relation between the fact and the mind is quite a chance one. Driesch's views are opposed to this conception. He regards each event as predetermined, and logic is to him of paramount importance. Even descriptive science must use the methods of the logician, for our speech, the very words which compose it, our judgements and inferences are all manifestations of pure logic.

The student of natural history makes use of language, of judgements, and of inferences to describe his objects. But he believes that it is the description which is of primary importance, while Driesch holds that the only part of natural science which is of any real importance is its method. He endeavours to present as science only that which is logically obvious. Thus he very soon reaches a priori ideas ideas which are obviously innate. This is not science this abstract science which Driesch gives us, a science which is incapable of any further development, which has no joy in detail or in original discovery.

Is biology then only the application of theories of knowledge to the facts of existence ? If so, what do our museums represent f What is the meaning of the joy experienced by the collector of plants and animals ? What the meaning of the satisfaction aroused by the discovery of a new fact ? What is the value of that innate curiosity which drives men on to new investigations ? In a somewhat different form Biitschli has advanced this same objection to Driesch's views:

'Apart from the fact that we do not study nature for the sole purpose of discovering her laws, but also because we desire to know something of the world in which we live, and of the universe around us, what, we may ask, is the reason of our interest in those laws laws which can, as a rule, only be expressed as rather uninteresting mathematical equations V (O. Biitschli, Mecbanismus und Vitalis- mus, 1901). There are, too, certain objections to the idea of en- telechy ; for example, that it gives us too atomistic a con- ception of the world. Driesch looks on such generalized

conceptions as Vertebrate animal', 'form', 'thought', as properties of entelechy ; he does not think that they, in themselves, have any real existence. This leads him to a very peculiar conception of history. History, he says, is always the history of bodies. Histories of science and of art are histories of men, of pioneers, and of artists. Every history deals either with the development of a body; or with the history of some corporeal quality, occurring in a series of bodies which are produced in sequence, the one by the other ; or finally (as in a history of Science), it is concerned with bodies which are only very indirectly related to each other, but of whom it is still true that each one has been produced by another of the series. History either gives us a picture of a development, as in the history of an individual, or it gives a culmination, linking up events with those that preceded them, as in a history of Science. Further, Driesch affirms that that history which is cumulative cannot be regarded as an exact science a science with its own definite laws.

There have been endeavours, it is true, to create philo- sophical history to present a history which describes the evolution of law, of culture, or of religion. But we have had to reject all such attempts, since they were all so inaccurate and inexact. Our study of history has not enabled us to formulate any general laws, and hence history cannot be regarded as an exact science. What is it, then ? How are we to classify the works of a Tacitus or a Taine ? What is Driesch's own History of Vitalistic Theories (T)er Vitalismus als Geschichte und Lehre') if it is not a work of science ? Driesch does not give us any answer to this question. Further, we cannot accept the view that Art and Science are nothing in them- selves, and that the world consists merely of so many mate- rial bodies. All history shows us that this hypothesis is wrong. It shows us how, at this or that time, these or those ideas were predominant, and how some ideas, far mightier than any individual, subdued whole masses, whole nations, to their service. We can follow these ideas,

from their very inceptions, through their growth, to their time of triumph, and thence onward through all the processes of decay. To do this we do not need to know very much about the actual material 'bodies'. Christianity, Monasticism, the Reformation, the Revolution, the State, Science, Darwinism all these denote something very real, something more fundamental than any mere aggregate of facts; there is a living idea behind each of them. A universal history (and Driesch was only considering uni- versal history) is not necessarily written to present ideas yet there were, and there still are, ideas behind any such history. The task of the historian is similar to the task of every other investigator; he must discover those ideas for they alone represent what is constant in the never- ceasing flux of material phenomena and he must describe their qualities. For the carrying out of this task the question 'Does an idea evolve?' is of minor importance. 'Did it exist ?' and 'What was it ?' those are the questions of vital importance for the historian.

We see, from his view of history, from his manner of regarding it merely as the sum of the productive efforts of a member of separate individuals, that Driesch was still strongly under Darwinian influence, in spite of his attack upon the theories of Darwin. The older historians had believed that their task was to search history for ideas. This 'philosophical history' was first rejected by Buckle; he was the first to assert that the progress of civilization had been simply due to the accumulated efforts of indi- vidual men. Since his time this atomistic conception has been predominant. It has been specially prevalent in the writing of the history of Science; such history, it is thought, is nothing but the presentation of a series of new dis- coveries. This idea is also predominant in all Darwinian speculation. Darwin himself banished Nature, as a creative force, out of the realm of science ; he it was who first declared that only separate individuals have any real existence. He attacked the ideas of species, of orders, of plans, and affirmed that such ideas do not correspond to

any existing reality. He forbade the search for ideas behind the history of organisms, and thought that the sole aim and end of science should be the explanation of facts. Driesch agreed with Darwin on all these important matters. Driesch objects to mere descriptions, to all classifications arrived at by induction, since these only present us with facts, and not with facts which have been illuminated by the light of pure reason. He ridicules evolutionary trees as mere ancestral portrait galleries, in which we know nothing of the relationship of the various pictures. And yet What was the true significance of Haeckel's stormy campaign ? Was not he, too, claiming what Driesch claims, that we must abandon mere descrip- tion, discard all those systems which we cannot explain, and work towards a higher science, by which we shall be able to 'understand' and to 'explain* ? Did not Haeckel endeavour to explain the ancestral types which Cuvier had made known to us, not by entelechy, it is true, but by phylo- geny ? Driesch does not reject the ideas of phylogeny. On the contrary, he thinks it extremely probable that living forms are descended from one another in some such way as phylogenists suggest. But he wants to know exactly how the whole process happened.

There is another matter in which he shows himself to be your true evolutionary philosopher. He has proved, to his own satisfaction, that it is erroneous to speak of an Idea manifesting itself in the history of the world. Never- theless he returns later to the subject and suggests that history does, after all, perhaps reveal some such Idea. True it is, as he assures us, that he cannot prove the existence of any such harmonious universal purpose ; never- theless he believes that there is one. From belief to accep- tance as proved is but a short step. Driesch will not take that step, but there are many who do not hesitate to do so. Kant, too, had declared that the Absolute is never known and never can be known; yet his followers the Romantic Philosophers made this Absolute the basis of their philosophy, the only real thing left in the universe.

In reviewing the story of Driesch's work we see happen- ing once more what may happen to any original thinker. He believes that he has discarded the Darwinian ideas, but in reality he has succumbed to them. This shows us that Darwinism is not so easy to refute, is not so easily uprooted, as it would at first sight appear. Who can say what depths of thought will be discovered in it by the generations yet to come depths hidden from us, who stand too near to the whole story ? We have only the first rude beginnings of all that discussion and criticism which will be necessary before mankind can form his final judgement.

Since the above chapter was written Driesch has developed his ideas still further. In his Philosophy of the Organic World he has left biology far behind ; the work is pure philosophy : it deals with theories of knowledge and with metaphysics. Since 1905 Driesch's contemporaries have looked upon him as a philosopher rather than as a scientist. 1 1 Among the most important of Driesch's philosophical writings are: Ordnungslebre, 1912; Die Logik ah Aufgabe, 1913; Wirklichkeitslehre, 1917; Wissen und Denken 9 1919. O. Heinichen has given an account of Driesch's philosophy in his Driesch's Philosophic, eine Einfuhrung, 1924.

IN the 'seventies and 'eighties of last century Darwinian ideas dominated biological thought, and it was uni- versally admitted that speculation in other fields of science was being strongly influenced by the same ideas. Investi- gations were pursued with one aim in view inquiry into the causes of phenomena; the only questions discussed were those concerning the origin and ultimate fate of material things. Lichtenberg's nickname of a cause-seeking animal ('wahres Ursachentier 5 ) never fitted mankind better than during that epoch. The last anti-Darwinian works of any importance had appeared at the end of the 'seventies. The controversy still continued sporadically, the idealists still published an occasional protest (e. g. Michaelis) ; but no one paid any attention to them, though now and again . there was an appeal for some form of compromise between the new teaching and the old belief in an Almighty God.

Delpino, a professor of botany at Genoa, accepted the Darwinian principle of Natural Selection (1880); never- theless he pointed out that there is an enormous gap, which cannot be bridged, between the living and the non-living. He affirmed that, in the existence of sensation, of the understanding, of the will in the whole range of life, from the amoeba to Man the domination of an All- powerful Deity is manifested. The Darwinists merely shrugged their shoulders over such objections to their purely scientific ideas.

Natural history was looked upon as the most firmly established and the most progressive of the sciences, since it had succeeded in proving what all were anxious to prove : that matter and force are all-important that idealism was dead. Proudly she endured the odium theologicum of the Church that Church looked on helplessly while her strongholds were overthrown by the spread of the growing conviction that a man is only a superior monkey. It was generally held that Darwin had succeeded in doing what the great revolution had failed to accomplish. Man- kind had at last thrown off all the chains binding him to his own ethical, religious, and scientific past. A new era had dawned, dominated by a scientific outlook on reality. Psychologists, lawyers, philologists, sociologists, philoso- phers all admitted modestly that there was no finality in their sciences, and they looked up to biologists as the only possessors of absolute knowledge. Darwin, Weismann, and Haeckel were authorities who could solve every problem and banish every doubt.

This complete domination of contemporary thought by the Darwinian point of view did not last long. After the 'eighties one realm after another was lost to it, until finally it reigned supreme only in the field of biology. Zola was at the height of his fame in the 'eighties; yet in 1889 Bourget, in his introduction to Le disciple, rejected the idea that man is merely a bundle of natural instincts ; he criticized the exaggerated cult of natural science, and pointed out that even science is full of mystery. The work of Brunetiere, another critic of Zola, was very well received, and his protest against the scientific ideals of Condorcet, Comte, Renan, and Berthelot caused much discussion. His phrase 'the bankruptcy of science 5 (1895) passed from mouth to mouth, and neither in France nor in any other country was there an opposition strong enough to weaken the effect of this criticism. The time when a du Prel could assert that poetry represents an 'antiquated point of view', and that it would be exterminated by the advance of science, had passed. Decadents and mystics followers of Neitzsche and of Bergson grew rank and luxurious amidst the ruins of the scientific edifice.

Scientific philosophy, too, which deduced unwarranted conclusions from scientific hypotheses, is also in decay. Spencer's name is referred to less and less in books on philosophy. Haeckel's monism, once regarded as a very important philosophical system, became the view of a very minor group. Taine is attacked as insufficiently scientific. Kant, Hegel, Schopenhauer, the Romantics, and Naturalism all these are coming once more into repute. Interest in religion revives. Scientific attacks on the literal accuracy of the Bible are out of date ; history, archaeology, and philology once more play their part in Biblical criticism. What is of even greater importance, we speak again of 'the necessity for religion'. Not philoso- phers only, but scientists too (e.g. Reinke), introduced the idea of God into their discussions. The times were gone by when Comte could speak of theology as ' a childish study'. Protestants (Harnack, Sabatier, &c.) united with Catholics (Loisy, Schell, and others) in the study of their subject with renewed interest. The struggle of the modernists for 'progress within the Church' was a sign of the times. In the sphere of ethics, too, the times when this was very strongly influenced by Spencerian dogmatism are long past those times when ethical laws were believed to be merely the products of utilitarianism, and morality merely the result of our social life. Nietzsche adopted a Spencerian attitude. Many of his ideas are derived from evolutionary theories. His 'blond beast', his 'superman', his glorifica- tion of physical strength, his belief in a better future, all show how much he owes to Darwinism. But gone is the respect for natural science, gone is the belief in a merely sociological morality. 'Thus spake Zarathustra: "Look, I am sated with learning, like the bee who has collected too much honey. I want the hands which can stretch them- selves out ".' Nietzsche's moral laws are based on a belief in the importance of the individual.

Spencer, the practical engineer, the believer in science, the champion of the 'average' in morality, the believer in the progress of society, gave place to Nietzsche, the poet and classical philologist, who paid with his own sanity for his hatred of average morality. There came a reaction, too, against the evolutionary view of history. Some workers still believe that science should formulate the empirical laws that governed past events, in the manner of Darwin. But the attempts initiated by Buckle and Taine to write history round these laws has long been abandoned. There is, it is asserted, a funda- mental difference between the methods of the natural sciences and of the cultural sciences. Dilthey says that the historian must describe, not explain. He should portray typical phenomena, each with its individual charac- teristics ; he should describe the actual events, rather than attempt to deduce general laws, as is done in natural science. Similar ideas have been expressed by Windelband, the philosopher. He places the writing of history among the descriptive (idiographic), natural science among the law- determining (nomothetic), studies. Rickert asserts that history and science are divided toto coelo ; the former aims at describing the particular, the latter at deducing the general. Historians with any leanings towards philosophy have already completely discarded the scientific method of interpreting history.

Among Asocial democrats the materialistic philosophy, which they adopted from the scientists, had reached its culminating point before the war. They have emancipated themselves from those purely rationalist views, deduced from a study of natural science, upon which Marx and Engels based their systems. Nowhere to-day, outside Soviet Russia, is the materialistic philosophy of Marx accepted as the basis of modern socialism ! Philology has long since freed itself from the shackles of Darwinism. Schleicher's pamphlet, which introduced Darwinian ideas into linguistic studies, appeared in 1863. In 1871 Whitney, an American philologist, criticized these views adversely. He held that speech does not develop independently of man's will ; it is a function of human life, an element of culture, and it may be altered at the dictate of the human will. This criticism did its work. In 1880, when Darwinism in its application to biology seemed still to be full of life, Delbriick declared that Schleicher's point of view had been superseded.

In chemistry, astronomy, and petrography the attempts made to introduce the Darwinian point of view were abortive from the beginning. In no department of science, other than biology, is the Darwinian conception the dominant one to-day. Public attention is focussed on modern physics, as interpreted by Einstein and Planck. Modern biologists hardly noticed how rapidly public opinion was changing. They believed that the reins by which our intellectual life is guided were still in their hands. The general atmosphere around them gave colour to this view. Sceptics might protest that Darwinian ideas were not applicable to their particular subjects, but they made no direct attack upon natural science, upon biology itself; they only pointed out that the biologists were not agreed about their fundamental principles. At this time Weismann's name was often cited in proof of the fact that the views of Darwin and of Haeckel were no longer receiving unqualified acceptance from biologists.

From the 'nineties onwards the positivist belief in the facts of science has been gradually undermined while the prestige of philosophy has increased. This movement re- sembles in many ways the German romantic movement of the early nineteenth century. Bergson was its protagonist. Beginning from the positivist point of view he discarded the nineteenth-century belief that the intellect is all- important. He relegated science to a place in the second rank. Its use is merely practical, for it adds to the well- being of mankind ; it has not been able to discover absolute truth. Only when man's subconscious mind is saturated with ideas relating to the meaning of phenomena will he be able to obtain some clue to final causes. It is, however, true that, in spite of this, Bergson, in his most important book, Creative Evolution, links up his work with that of Spencer and Darwin. He is examining the same problem the problem of the history of the organic world ; he

discusses the transmutation of species and the differentia- tion of specific qualities. He tries to obtain some explana- tion of the upward tendency exhibited by organic life, and searches, as did Darwin, for the driving force which lies behind organic evolution. Using very original arguments Bergson proves, however, that Darwinian theories do not really represent an effort to discover the history of events, to describe what actually happened. They merely display to us, in the manner of a cinematograph film, a series of forms which follow one another in time ; it is possible to picture these as all having existed simultaneously. Evolution was not thus ; it was a process of change, a continual process, an impetus. This, according to Bergson, has existed since life began as an elan vital. Bergson's theory did not directly influence evolutionary theories. But indirectly it was of considerable importance, for it added to the growing scepticism with which the Darwinian ideas were viewed.

The increasing importance attached to the experimental method is intimately connected with the rise of modern physiology. When the Darwinian influence was greatest Miiller's physiology was looked upon as ideal. It was a very theoretical physiology, which regarded form as the most important quality of the organism, and endowed all forms with functions. Those who came after Miiller re- stricted this aspect of their work to an examination of the sense-organs, regarding them simply as physical mechan- isms (e. g. von Helmholtz Wundt) ; this work culminated finally in investigations which belong to the realm of pure physics and psychology (e.g. Mach.).

This physiology of the sense-organs, marked by a strong philosophical bias, attracted general interest. Pure physi- ology, however, was felt to be of minor significance, and was chiefly studied by the medical faculty because of its practical importance. The more Darwinism flourished the more physiology declined. The physiologists seemed to be only interested in the nature of Man; they used animals (frogs, dogs, pigeons, rabbits, &c.) only for those experiments which could not be performed on human beings. The Darwinist could boast that his attitude was more philosophical and aimed at obtaining a more general knowledge of Nature. He only regarded Man as one organism, neither more nor less important than any other living form. Nevertheless, the evolutionary view was intimately connected with the physiological ideas pre- vailing at that time.