Writing at the end of the 19th century, John Theodore Merz, Nestor of 19th-century intellectual historians, remarked: “Germany may be said to have produced Darwinismus in this century as France created Newtonianisme in the last.”1 Merz’s remark proved entirely accurate. Germany indeed became the homeland of Darwinism. It was in Germany where it was first established, where it spread widest, and where it struck deepest roots. Quite justifiably, Darwin himself saw Germany as the best hope for the triumph of his theory; thus he wrote his friend Wilhelm Preyer in March 1862: “The support which I receive from Germany is my chief ground for hoping that our views will ultimately prevail.”2 Darwin succeeded beyond his wildest dreams. Had he lived until the end of the century, he would have been astonished to learn the results of a readers’ survey conducted by the Berliner Illustrierte Zeitung in 1899. Asked to list the three greatest thinkers of the 19th century, readers named Helmuth von Moltke, Immanuel Kant and Charles Darwin, in that order; but they deemed the most influential book of the century to be The Origin of the Species.3
Why had Darwin become so popular in Germany? There is no easy answer to this difficult question, and we can only indicate some central factors here.4 Social and political factors played a major role. Darwin meant different things to different political factions in Germany, and he was used to justify both right- and left-wing views. But if we ask about the social and political factors behind his initial reception, the reasons he first became popular, then we must consider his strong appeal to left-wing intellectuals. The collapse of the liberal and nationalist cause in the Revolution of 1848 had led to consternation and frustration among left-wing intellectuals, who would now have to fight for their cause through intellectual rather than political means. What they could not achieve through the barricades or ballot box, they would now attempt through science and philosophy. Left-wing intellectuals were intent on creating a humanist, secular and materialist worldview, one which would support human autonomy and democracy. Central to that objective was undermining the traditional alliance of throne and altar, whose ideology seemed to rest on hypostasis and heteronomy, the alienation of human autonomy through belief in supernatural forces. Darwin’s theory, in eliminating the need for supernatural intervention in the universe, seemed to confirm the left’s worldview, and so to be a useful weapon to undercut the alliance of throne and altar.
Although it is alien to our present understanding of Darwin,5 the early German Darwinists associated Darwin’s theory with social and political progress. What Darwin saw in nature—the increasing perfection of a species through the struggle for existence—they saw in social and political life. Darwin seemed to make social and political progress into a natural law, so that greater autonomy and democracy would inevitably triumph. Nowhere is this line of thinking more evident than in Ernst Haeckel’s famous and influential lecture ‘Ueber die Entwicklungstheorie Darwins’, which he gave in Stettin on September 1863 at the Versammlung deutscher Naturforscher und Ärtze.6 At the close of his lecture, Haeckel makes clear the political meaning of Darwinism for him, and later much of his generation:
Do we find the same law of progress [as found in nature] active everywhere in the historical world? Quite naturally so! For also in civil and social relations it is the same principles of the struggle for existence and natural selection that drive the people irresistably forwards and gradually to higher culture. Regression in state and social life, in moral and scientific life, which the self-serving efforts of priests and despots in all periods of world history have been intent on producing, can indeed temporarily hinder this universal progress or apparently repress it; but the more unnatural, the more anachronistic, these reactionary strivings are, the more quickly and forcefully will they create progress, which will follow hard on their [i.e. the despots’ and priests’] heels. For this progress is a natural law, which no human force, neither the weapons of tyrants nor the curses of priests, can ever repress. Only through progressive movement is life and development possible. Even standing still is a retreat and every retreat carries the germ of death in itself. The future belongs only to progress!7
There were also, of course, intellectual factors behind the triumph of Darwinism. Darwin’s seed fell on fertile and well-prepared soil in Germany. In the 1840s the “biophysics programme” of Helmholtz, Theodor Schwann (1810–1882), Ernst Brücke (1819–1892) and Emil Du Bois-Reymond (1818–1896), had advanced the cause of a purely mechanical explanation of life. And in the 1850s the rise of German materialism had gone a radical step futher in maintaining that all life and consciousness consists in nothing more than matter in motion. Vogt, Büchner and Moleschott had been especially active and successful in promulgating and popularizing the materialist cause. Indeed, in 1851 Vogt had published a translation of Robert Chambers Vestiges of Creation,8 an amateurish harbinger of Darwin’s theory, which had appeared in Britian in 1844.9 The biophysicists and materialists were, on the whole, extremely receptive of Darwin’s theory, which seemed to provide strong empirical support for their views.10 Even though Darwin himself was reluctant to express materialist views, the German materialists were not so hesitant in enlisting him for their cause. Soon enough, Darwinism and materialism became closely associated among the German public. Darwin would never create scandal and shock in Germany as he had in England, because the materialists had already prepared the public for him. As Frederick Gregory puts it: “Once Germans had been told that man’s mind could be compared to urine, it came as no shock that man was now supposedly related to apes.”11
With these political and intellectual factors in its favour, Darwinism spread rapidly in Germany. Within weeks of the publication of On the Origin of Species in Britian in 1859, Heinrich Georg Bronn (1800–1862), professor of zoology at Heidelberg, offered to translate it into German.12 His translation appeared in 1860, and then was reprinted in 1862. At first, the reception of Darwin was rather slow and cautious, leading Huxley to remark “Germany needs time to consider”.13 The real breakthrough for Darwin came with Haeckel’s 1863 lecture. Speaking with all the zeal of a new convert, Haeckel inspired the public, sweeping it along with his enthusiasm. The Stettinger Zeitung for September 20, 1863 noted its effect on the assembly, stating how Haeckel “captivated the audience” and how “a huge applause followed this exciting lecture”.14 But Haeckel was only the first of many talented and spirited spokesmen for Darwin. In the 1860s Alfred Brehm, Carl Vogt, E.A. Rossmüller, Fritz Müller, Wilhelm Preyer, Friedrich Ratzel and Ludwig Büchner all rallied to advance Darwin’s cause. Such was the swift ascent of Darwin that, by the late 1860s, he dominated discussion in the life sciences. Writing in 1875, Friedrich Albert Lange stated in the second edition of his Geschichte des Materialismus that the dispute over materialism had now morphed into a dispute over Darwin.15 The old German materialists faded into the background, Lange said, so that a new edition of Büchner’s Kraft und Stoff no longer created an outcry, and so that old Moleschott was nearly forgotten. Now all attention was focused on Darwin, and one had to be either for or against him.
It has been estimated that, already by the middle of the 1870s, Darwinism had triumphed in Germany.16 The Darwinians were growing in numbers and influence—Haeckel and Carl Gegenbaur were now professors in Jena—and they had control over major journals, such as Ausland and Kosmos. The ranks of the anti-Darwinians, who belonged to an older generation, were dwindling in number and energies. Only Adolf Bastian, Albert Wigand and Rudolf Virchow mounted a rear guard action on behalf of the weakening anti-Darwinian cause.17 Commenting on the rapid rise of Darwin in 1875, Otto Liebmann reckoned that, apart from religious bigots and a few crackpots like himself, almost all intelligent opinion in Germany was now on the side of Darwin.18 “Sir Charles”, as he now needed to be called, had so grown in prestige that he received institutional recognition: in 1867 he was made a knight of the Prussian order Pour la Mérite, and in 1878 he was elected to the Berlin Akademie der Wissenschaften.19
It is a remarkable fact that the rise of Darwinism coincides with that of neo-Kantianism in Germany. Both movements came into their own in the 1860s, and both became dominant forces in the 1870s and 1880s. The relationship between these movements very much depends on whether Darwinism was associated with materialism. Some neo-Kantians wanted to make a sharp distinction between Darwin’s theory of natural selection and materialism: while his theory was founded on observation and experiment, materialism was a more general philosophical worldview that drew unfounded conclusions from it. If Darwinism meant simply the theory of natural selection, then the neo-Kantians were happy to endorse it. They encouraged the naturalism and mechanism of Darwin’s theory, which they saw as a crucial step forward in the progress of the sciences. If, however, Darwinism was associated with materialism, and especially with the doctrines of Ernst Haeckel, the neo-Kantians were ready to fight it tooth and nail. They saw Haeckel as a disguised materialist, who needed to be exposed and refuted.
There was no party line in the neo-Kantian response to Darwinism. The three neo-Kantians of the 1860 generation who were most active in responding to Darwinism—Friedrich Albert Lange, Jürgen Bona Meyer and Otto Liebmann—had very different reactions to it. While Lange was completely enthusiastic, Meyer was totally sceptical, and Liebmann was lukewarm, ready to meet it only halfway. While Lange and Meyer were happy to see the end of the Aristotelian tradition, Liebmann was bent on preserving it and tried to combine it with Darwinism. Though very diverse, these reactions to Darwin are still describable as “Kantian” insofar as each emphasizes different aspects of the Kantian legacy. Lange represented Kant’s naturalism and mechanism, Meyer his scepticism, and Liebmann his dualism.
It is only at the end of the century that the relationship between neo-Kantianism and Darwinism began to sour. The publication and popularity of Ernst Haeckel’s Die Welträtsel in 1899 alarmed the neo-Kantians. Here was a very successful book which was, its author’s disclaimers nothwithstanding, essentially materialist, and which claimed to be based upon Darwin’s theory. For some neo-Kantians, Haeckel represented a resurrected materialism with a Darwinian face. Two later neo-Kantians, Friedrich Paulsen and Erich Adickes, were moved to write polemics against him. It is with Paulsen’s and Adickes’ polemics that another side of the Kantian legacy comes especially to the fore: its anti-materialism.
The rise of Darwinism, its remarkable success as a scientific hypothesis about the origin of species, raised a very important question for neo-Kantianism: Can biology be a science? Kant’s own negative verdict on this question seemed to be antiquated by Darwin’s success. Kant had denied that speculation about the origin of species could remain within the limits of experience; and biology hardly fit his own mathematical paradigm of science. The great challenge to neo-Kantianism in the second half of the 19th century would be in responding to the rise of the new sciences. Somehow, it would have to reconceive its paradigm of science to match the de facto progress of the sciences. Not to do so would be to relegate Kant’s philosophy to an older scientific age and to undermine its credibility as a 19th-century philosophy. We shall see in this chapter how neo-Kantians responded to this challenge with regard to biology.
Our task now is to examine the neo-Kantian response to Darwin’s theory, first in the 1870s in the work of Lange, Meyer and Liebmann, and then in the early 1900s in the polemics of Adickes and Paulsen against Haeckel.
The first neo-Kantian to discuss Darwin at length and in detail was Friedrich Albert Lange. He wrote about Darwin in the first edition of his Die Arbeiterfrage, which appeared in 1865;20 and he did so again in the first edition of his Geschichte des Materialismus, which was published in 1866.21 In the second volume of the second edition of his Geschichte, which appeared in 1875, he added much new material about Darwin, so that the original twelve-page discussion evolved into a forty-four page chapter devoted to the topic of ‘Darwinismus und Teleologie’.22 In some retrospective passages from the second edition, Lange noted that Darwinism was a novel theme when he had discussed it in the first edition (II, 240).23 The battle lines had not yet formed; Darwin’s friends had still not organized themselves; and his foes had not fully absorbed the meaning of his teaching. By the time of the second edition, however, Darwin dominated the field. All discussion in the life sciences centred around his work. The debate had so advanced that Lange felt it necessary to go into much more detail if he were to say anything worthwhile.
Of all the neo-Kantians to treat Darwin, Lange was by far the most sympathetic. All his materialist leanings, which are usually implicit in his Geschichte des Materialismus,24 become fully explicit in the case of Darwin. For Lange, Darwin was nothing less than the Empedocles of the modern world,25 the greatest contemporary spokesman for scientific naturalism. Lange saw the theory of natural selection as the triumph of that naturalism, because it finally demonstrated that naturalism could explain the organic world as well as the inorganic. While Liebmann would later object to Darwin’s theory on philosophical grounds, and while Meyer would quarrel with it on empirical grounds, Lange endorsed it both philosophically and empirically. Philosophically, Darwin had taken a great stride forward in creating a naturalistic worldview that could satisfy heart and intellect (243). And, empirically, his theory pulled off that rarest of feats: it was a unified explanation of the world not falsified by any facts (243). While Lange realized that many parts of Darwin’s theory were hypothetical, he was fully confident that, with more research, confirmation was forthcoming.
Darwin’s influence on Lange first appears in his political theory. In his Die Arbeiterfrage, a classical text of early German socialism, Lange gives a central role to the Darwinian theme of the struggle for existence. Lange takes this theme directly from Darwin’s Origin of Species, “this epoch-making book”, which he cites at length in his first chapter. Five years before Darwin’s Descent of Man,26 Lange maintains that this theme applies to human beings as much as it does to plants and animals. He sees the struggle for existence taking place chiefly in the market place of civil society (8). Just as in nature individuals of the same or different species struggle against one another for their survival, so in civil society workers have to compete against one another to earn the means of their subsistence; and just as nature produces an abundance of seed to create a single plant, so there is an enormous supply of workers where only a lucky few get a living wage. Natural selection and the struggle for existence mean that the strong will rule over the weak not only in nature but also in society, so that there will always be an elite to dominate the masses (66). Lange even imagines that if the present class differences persist for millenia, they will create racial differences between workers and bourgeoisie (70). Unlike Haeckel, then, Lange does not think the Darwinian mechanisms lead to greater progress and perfection; rather, he argues the very opposite: they will result in oppression and misery. It is a grim picture of human social life that Lange portrays in Die Arbeiterfrage, one so dire that he does not even allow his reader the little consolation that Darwin provides at the close of Chapter 3 of Origin of Species.27 Man knows the terrors of annihilation that await him, he feels oppressed by the unrelenting struggle for survival, and there is no assurance that the virtuous survive and multiply (12).
So far Lange might sound like an early social Darwinist, that is, someone who believes that society should be organized on the principles of natural selection, as if the elite few who win out in the struggle for existence have a right to their social position on the grounds of their natural superiority. But Lange’s use of Darwin is motivated with the very opposite intention: to show the plight of the workers and the need for drastic social and political reform, whose purpose is to cancel the effects of natural selection. Unlike the social Darwinist, Lange regards neither natural selection nor the struggle for existence as an inescapable fate: mankind can and should struggle against these natural forces to correct or ameliorate their effects through institutional and political means. There are two conflicting forces at work in Lange’s social and political universe: natural ones, which work towards inequality and domination through the struggle for existence; and spiritual or moral ones, which strive towards equality and freedom for all. History consists in the eternal battle between these forces. If these conflicting forces appear to reflect Kant’s dualism between the realms of freedom and nature, it is necessary to recall that Lange had questioned that dualism in his Geschichte des Materialismus, placing all moral acts in the phenomenal world.28 One might well question, however, how Langean man escapes the struggle for existence, how he can cancel its effects, without that dualism. Arguably, in his social and political theory, Lange presupposes the very Kantian dualism that he brings into question.
In the hope of collaborating with Marx and Engels, Lange had sent them copies of Die Arbeiterfrage in March 1865. They took issue with the book, however, chiefly because of its Darwinian theme. In a long letter to Lange written March 29, 1865,29 Engels explained that the problem of modern civil society—the gross inequality in wealth—had its source not in nature but in social and economic relations, in the system of private ownership of the means of production and in the resulting class conflict. Economic laws are not eternal laws of nature but the product of human beings, of their social and political relations at a specific moment in history. Engels implied that Lange was making the same mistake as the classical political theorists: the hypostasis of social and political relations, making a natural law out of what is the result of society and history. Taking note of this criticism in a later edition of his Die Arbeiterfrage,30 Lange replied that there would not be class conflict in the first place if workers were not compelled to compete against one another and to sell themselves on the marketplace to earn the means of their subsistence. Competition and the need to subsist were basic natural facts behind social conflict. The power of a captain of industry over his workers was simply an expression of his dominant position in the struggle for existence.
Darwin was crucial for Lange’s worldview as much as his political theory. The modern Empedocles seemed to vindicate Lange’s steadfast naturalism, mechanism and nominalism, his long-standing opposition to the teleology and (conceptual) realism of the Platonic-Aristotelian tradition. Because Darwin had aroused so much opposition, Lange felt called upon to defend him, and duly did so in his Geschichte des Materialismus. Much of his chapter on Darwin is a critique of his many foes, “our new Aristotelians”, as Lange calls them. Opposition to Darwin, Lange maintains, chiefly comes from those who still cling to the old teleological conception of the world. Their defence of this teleology rests on the premise that there are gaps in natural explanation which can be filled only with the idea of purpose (245). They understand creation in nature on analogy with human creation of an artefact: just as we would make a machine, so God produces an organism according to intelligent design. But this anthropocentric conception of teleology, Lange argues, has been completely defeated by the theory of natural selection (245). Putting aside all Darwin’s analogies between natural and domestic selection, Lange stresses one important implication of the theory of natural selection: that nature does not create life in the same manner as we create an artefact (246–247). To produce an artefact, we choose the simplest and most effective means to our ends; there is no room for chance because we work to produce exactly what we intend. To create an organism, however, nature appears to work by chance, adopting a blunderbuss approach, spewing forth millions of seeds for only a few of them to survive and germinate. If we measure the production of a plant by human standards, it seems as if nature works by “blind chance” or “dumb luck”. If a seed finds fertile soil and germinates, that is the exception rather than the rule. What succeeds in nature is therefore “the lucky special case in an ocean of birth and death” (248). The old model of teleology is deeply misleading, Lange concludes, because it makes this exception into the rule, as if nature somehow followed a norm or plan.
Much of Lange’s opposition to teleology was based on his assumption that teleology means an interruption of, or intervention in, the mechanical processes of nature (272). But attacking that concept of teleology seemed like charging against open doors. For who, in the mid-19th century, held that supernaturalist concept of teleology anymore? The conception of teleology advanced by Schelling and Hegel in the early 1800s, and then revived by Trendelenburg and Lotze in the 1840s, stressed that purposes work through mechanism, which is the necessary means for their fulfilment. Lange duly notes this conception of teleology, which he even calls “correct teleology”. But he immediately restricts the force of this concession by invoking Kant’s regulative doctrines. Although we constantly use the idea of purpose in the life sciences, it has no metaphysical validity, that is, we cannot assume that it is true of nature but we can only proceed in our enquiries as if it were so. Kant, Lange explains, has two conceptions of teleology, both of which are compatible with a naturalistic worldview (276–277). One is the formal conception of purposiveness, according to which we proceed in our enquiries as if nature formed a system according to genera and species; the other is the objective concept of organic unity, according to which we treat natural products as if they were the result of design. In neither case, Lange notes, are we justified in assuming that there really is some purpose in nature. Kant’s teleological principles mean not that mechanical explanation comes to an end, as if at some point purposiveness takes over, but only that the process of mechanical explanation is an infinite task (277). For Lange, then, the idea of purposiveness would prove superfluous with the complete mechanical explanation of the world. While he approves of Kant’s regulative doctrine, he thinks that Kant went astray in thinking teleology to be a necessary manner of thinking for the human mind (276). The more science progresses, Lange is confident, the more it will eliminate this old pre-scientific manner of thinking.
Another topic in Lange’s defence of Darwin was the concept of species. Some discussion of this topic was inevitable, given that the doctrine of fixed and eternal species was a major source of resistance against Darwin. The doctrine was so entrenched that even materialists like Carl Vogt clung to it.31 Lange, though, has little patience for opposition on this score. There is no more conspicuous example of superstition and prejudice in science, he declares, than the still prevalent belief in the concept of a fixed and eternal species (241–242). The reason this concept is so prevalent and deep-rooted, he explains, is because of its ancient origins: it goes back to the Aristotelian tradition, according to which universals exist in things (301, n.54). As a convinced nominalist, Lange claims that the belief in eternal and fixed species is wrong in principle: it rests on the classical malady of hypostasis, which can be cured with a little conceptual surgery.
Though hypostasis motivated all his animus against the old Aristotelian doctrine, Lange does not stress this theme in his chapter on Darwin. Instead, he makes two points about the fixed species doctrine, both intended to demonstrate its obsolescence and redundancy (253–254). First, it is the result of doing biology without a microscope and starting from the higher end of the living scale. If, however, we begin our biology with that instrument to examine the lower end of the scale, we are utterly overwhelmed with the profusion and complexity of life forms, which do not easily fall into the Linnaean classificatory scheme of genus and species. Second, Darwin’s theory can explain the relative permanence and stability of species, so it can account for the appearance of fixity so insisted upon by Darwin’s foes.32 When creatures establish themselves and adapt to their environment, they can live and breed for milennia, as long as their environment remains the same. We can account for the concept of a species, then, without all the metaphysical afflatus of a concrete universal or the theological baggage of a supernatural creator.
Another enduring aspect of the Aristotelian legacy, which Lange believed he had to eradicate, was the idea of organic form. Even hearty mechanists like Virchow and Vogt could not bear to part from this idea, which they used to explain the essence of an individual (250–251). For Lange, however, this idea is just another relic of scholasticism. Crucial to the idea of organic form are two old Aristotelian assumptions: that the whole is prior to its parts; and that every part plays a necessary role in the whole. Lange finds both assumptions utterly obsolete. “Not much can be done with the old mystical idea of the dominance of the whole over its part”, he confidently informs us (251). As a mechanist, Lange holds just the opposite view: that the part is prior to the whole, which is only the sum of all its parts. Modern research has defeated Aristotelian holism, he argues, because it shows that a cell can live without the whole organism, just as the heart of a frog continues to beat after its dissection (252). Nowadays one takes parts of one body and attaches them to another; and there are creatures at the lower end of the organic scale which come together by the fusion of independent cells. Wisely, though, Lange did not push his mechanist assumptions too far. He admitted that the old Aristotelian assumption is valid “for the most part” and limited himself to denying that it is not a necessary metaphysical truth (252).
As part of his polemic against organic form, Lange also targets the assumption that there is a natural or real unity to things. The assumption seems natural because a plant or animal forms a unit, a single whole, which appears self-sufficient and independent of other plants and animals. But for Lange this assumption too is a lingering remnant of Aristotelianism. We think that there is a natural unity because we assume that there is a universal, a genus or species, existing in things and holding them together. For Lange, however, the unity of a universal is only due to an act of the mind, and there is no reason to assume that it is really inherent in things. What we see as a unity is entirely relative, because there is nothing unnatural or false about regarding each part of an organism as a unity (251). We can see not only the whole plant but also its stem, leaves and bud as one. Furthermore, the idea of an independent life can be applied as much to the part as to the whole. Much of Lange’s argument here seems indebted to the latest research, especially to Haeckel’s work on tiny marine invertebrates, the radiolarians.33 Haeckel observed how these creatures could both lead an independent life but also could fuse together to form a single organism. Whether the radiolarians were a unit or a part, Haeckel concluded, was simply a matter of convenience, depending on the perspective of the scientist.
In his radical nominalism, and in his insistence upon the merely conventional and relative aspects of classification, Lange is not an entirely faithful Darwinian. In the Origin of Species Darwin retreats from a radical nominalism which would make all classification simply a matter of convention or convenience.34 According to Darwin, classification should be neither Aristotelian nor conventional but “geneological”, reflecting the origin of a species through its line of descent from primitive ancestors. We will leave aside here, however, the question to what extent Lange was a faithful Darwinian. It was never his intention to be a Darwinian bulldog or bard. His chapter on Darwin in his Geschichte des Materialismus is devoted not only to a defence but also a revision of Darwin’s theory. For all his admiration of the English Empedocles, Lange finds problems with the formulation of his theory, problems which make it vulnerable to objections. To avoid these objections, revision and qualification are necessary, he advises (272).
Darwin’s major mistake, Lange believes, is in putting too much emphasis on natural selection, as if this were the only mechanism behind the evolution of new species. In stressing this mechanism alone Darwin is guilty of characteristic “English extremism” (263). Natural selection alone cannot explain the origin of a new species, Lange argues, because it determines only which organisms are actual, which are going to survive; it does not determine, however, which are possible in the first place, which are among the pool of contenders in the struggle for existence (266). Lange also finds Darwin’s theory problematic on the standard grounds that it provides no clear explanation for the source of variation. Darwin gets into trouble because he separates variation from change in environment, as if there were no connection between “changes in form” and “changes in the conditions for existence” (257). This makes it seem as if the production of useful variations were entirely a matter of chance, so that it is hard to understand the creation of useful characteristics and adaption to the environment.
To remove these apparent problems with Darwin’s theory, Lange proposes postulating what he calls “a law of development” for each organism, a law that determines its characteristic structure and distinctive stages of growth (263). Such a proposal had been advanced by several leading zoologists and anatomists in Germany—by Bronn, Karl Ernst von Baer (1792–1876), Albert von Kölliker (1817–1905) and Carl Nägeli (1817–1891)—and it was a common theme of their reaction to Darwin.35 Lange explicitly endorses their proposal. What exactly is meant by this law of development is unclear, however, and its meaning varies from one writer to another. For Lange, it means that an organism has the inherent striving to survive and to adapt to new circumstances, so that if its environment changes, it has within itself the “disposition to variation” which generates new characteristics more adaptable to its altered world (255–256). This seems to inject a note of Lamarckianism into Darwin’s theory, according to which an organism will inherit new characteristics from its attempt to adapt to its environment. Sure enough, Lange reads Darwin in this Lamarckian manner, praising him for having proved the inheritance of acquired characteristics (266).
In postulating a characteristic “law of development” for each kind of organism, Lange seemed to be falling into the old pitfall of substantial forms. Indeed, had not Leibniz attempted to explain the Aristotelian concept of an entelechy in just this manner, in terms of the distinctive laws of growth of an organism? Lange protested, however, that his law of development is not intended to be something “mystical” or “supernatural”, still less something purposive. Rather, it is nothing more than “the unique combination of laws, thought as a unity, which produces the appearance of development [of an organism]” (265). These laws are completely mechanical, and each kind of organism consists in a unique combination of them. To arrest any doubts that he had in mind something “mystical” or teleological, Lange explores a suggestion of Haeckel’s to the effect that “the plan” behind the growth of an organism consists in nothing more than the special way in which its carbon molecules combine with one another. Haeckel noted how carbon is constitutive of all life, and how the laws of combination of carbon create its complex structure. Hence Lange proposes that the law of development consists in nothing more than “the law of substitution for carbon combinations” (266).
On one important point Lange distances himself from an “extreme Darwinism”: the theory of “monophyletic descent”, that is, the derivation of all organisms from one and the same primal being (270). This hypothesis had been put forward by Haeckel as the final conclusion for Darwin’s theory of descent.36 Lange thinks that the theory might be true; but he is cautious about it and the whole doctrine of recapitulation. “The simple forms that all organisms pass through are not necessarily essentially alike”, he stresses in an italicized passage (270). We must be careful for mistaking a mere morphological affinity for a real identity, he warns, because we need to take into account the finer microscopic structures and chemical elements of these apparently similar forms; these structures and elements could be very different, despite their morphological likeness. The theory of monophyletic descent is extreme and implausible, Lange finds, because it assumes all differences between organic beings arise from natural selection alone, not having to take into account any difference in inner development. It is more plausible to assume polyphyletic descent, according to which the basic types of organisms derive from different original seeds; such a hypothesis at least accounts for the great variety of different forms (271).
Much more could and should be said about Lange’s reaction to Darwinism. His chapter on the subject in the Geschichte des Materialismus is rich, complex and nuanced, going into detail about many issues, which we cannot do justice to here. Here we have provided only a superficial summary of the major themes.
Of all the neo-Kantian critics of Darwin, the most critical yet best-informed was Jürgen Bona Meyer. Having been trained in medicine, Meyer was well-qualified to discuss issues in anatomy, zoology and embryology; and he was well-studied in recent French and German biological literature. No less important, he was well-versed in the history of the life sciences. As a student of Trendelenburg, Meyer wrote his habilitation thesis on Aristotle’s biological writings. Remarkably, though, none of Trendelenburg’s neo-Aristotelianism animus against Darwin affected Meyer’s own judgement. Though he regarded Aristotle as the “the father of organic natural science”, he did not regard his thinking as a model for future biology.37
As soon as Darwin’s work appeared, Meyer devoted careful attention to it. He was a close reader of the Origin of Species and The Variation of Plants and Animals. In 1866 he wrote a long review for the Preussische Jahrbücher of the German translation of the second edition of the Origin of Species.38 A few years later, in his Philosophische Zeitfragen,39 he devoted a substantial chapter, some sixty-five pages, to an exacting examination of Darwin’s work.
Although Meyer was harshly critical of Darwin, he also greatly respected him. His critique begins with a tribute. There should be no question in anyone’s mind, he declared, that Darwin’s work, in its thoroughness, exactitude and erudition, has contributed greatly to the advancement of science (44). Whatever one thinks of his specific conclusions, Darwin made a major contribution in raising questions that until recently had been regarded as settled (72). More specifically, he had forced naturalists to reconsider the doctrine of the fixity of species, which had become a virtual dogma in the early decades of the 19th century. George Cuvier (1769–1832), the head of the Académie des Sciences, had reaffirmed that doctrine with renewed zeal and energy in his Règne animal (1817).40 Because he had insisted on exact observations, because he had condemned the speculations of Naturphilosophie, and because he amassed so many facts in its favour, Cuvier’s doctrine seemed to represent the standpoint of exact science (42). The transformationist theories of Lamarck and Geoffrey Saint-Hilaire, by contrast, seemed speculative fantasies because they lacked empirical data to vindicate them. Fortunately, Darwin’s questions came at just the right time because, by mid-century, newly-discovered paleontological facts had discredited much of Cuvier’s doctrine. After Darwin, no one could question that species change, Meyer wrote, and the only questions had become how they do so and to what extent they do so (54, 86).41 Writing in 1863, Karl Vogt, a new convert to species change, summarized Cuvier’s embarrassment: “It was only thirty years ago that Cuvier said that there are no ape fossils and that there cannot be any—and today we speak of ape fossils as if they were old friends.”42
It was one of Darwin’s central contributions, Meyer maintains, to have questioned whether sterility is the most reliable criterion of a species. The old doctrine of the fixity of species had rested upon the fact that the interbreeding of species leads to either no result or sterility in the offspring. Sterility seemed to be nature’s way of marking a definite boundary between creatures by forcing mating to take place within a species. While there could be fertile breeding between varieties within a species, there could be none between species themselves. Darwin had cast doubt on this criterion in Origin of Species, asserting that many different species could unite with ease, whereas many similar ones could not cross at all.43 Fertility and sterility were matters of degree, and it was impossible to decide where fertility ended and sterility began.44 In any case, disputations about whether something is a species or variety Darwin regarded as “so much beating of the air”, partly because the terms are so ill defined, and partly because naturalists would forever argue in a circle, reasoning that successful interbreeding creatures ipso facto belong to the same species. While Meyer complains that Darwin cites insufficient evidence for the successful interbreeding of species (50), he praises Darwin for rejecting the value of fertility as a general criterion to distinguish species and varieties (72). On the whole, he thinks that Darwin was right to lay aside scholastic disputes about what constitutes a species and to submit the whole question about change of species to empirical investigation (50, 61).
Although Meyer thinks that Darwin was correct to question the fixity of species, he does not himself take a stand on the issue whether one species evolves into another. In keeping with his general scepticism,45 he adopted a neutral or agnostic position, neither affirming nor denying evolution. There was simply insufficient evidence to come to a decision on these matters, and so, like a good sceptic, he would cultivate his equanimity. As a critical philosopher, Meyer insisted that naturalists strictly observe the limits upon knowledge, and that they refrain from speculation beyond experience. In his opinion, both Darwin and his opponents had transcended these limits, drawing conclusions that went well beyond empirical verification. Alexander von Humboldt and George Cuvier had maintained the fixity of species on the slender grounds that there had been no change in many species since the time of the ancient Egyptians—a much too narrow time frame for such a broad generalization (57). Although Darwin cited evidence for the fluidity of species from a much wider time frame, all his evidence showed is that species had changed, not that one had grown out of another (56, 96–97). While Meyer stressed that there is nothing intrinsically wrong with hypotheses in the sciences, he demanded that one know the difference between hypothesis and fact, speculation and science.
It was in just this regard that Meyer deemed Darwin a great sinner. His chief criticism of Darwin is that he blurs these boundary lines, putting forward speculation as if it were science, hypothesis as if it were fact. This was a controversial point, given that Darwin, a schooled and scrupulous methodologist, was confident that he had stayed within the limits of experience, and that his results gave the vera causa of things.46It was indeed supposed to be the great merit of his work that it brought many issues within the realm of science that had hitherto escaped it. Meyer is well-aware of this alleged virtue of Darwin’s work, and to some extent is ready to agree with it (72, 90); but, in the end of the day, for reasons we shall soon see, he thinks that Darwin infracts his own methodological guidelines.
Noting a notorious ambivalence in Darwin’s theory, Meyer complains that Darwin has failed to explain, and even to develop a consistent position on, the sources of variation. Darwin had laid great weight upon the reproductive system and inheritance in explaining the origin of species, and he laid less emphasis on the environment because children of the same parents differ greatly though exposed to the same “natural conditions”.47 But Darwin hedged and vascillated on the question of the environment affecting variation, stating on several occasions that “natural conditions” could have a great effect on the reproductive system.48 On opposite pages he stated both that heredity was “by far the predominant Power” in variation, but also that “the conditions of life, from their action on the reproductive system” are “of the highest importance in causing variability”.49 Darwin’s hesitation on this important issue did not escape Meyer, who chastened him repeatedly for his obscurity on such a fundamental issue (61, 64, 66, 67–68). Of course, Darwin himself had stressed the great lack of knowledge surrounding the laws of heredity, frankly admitting in the first chapter of the Origin of Species: “The laws governing inheritance are quite unknown”.50 Although Meyer duly praises Darwin’s modesty on this score, he still finds that Darwin, given such an admission, goes too far in his speculations.
On the whole question of the role of heredity versus environment, Meyer, like Lange, did not see that much of a difference between Darwin and Lamarck. He was surprised by the number of Lamarckian explanations in Origin of Species, where Darwin would often refer to the role of use and habit in the formation of a species. In his one attempt to reconcile the role of heredity versus environment, Meyer argues, Darwin comes very close to Lamarck, so much so that their positions become virtually indistinguishable. Darwin stated that while “natural conditions” have an indirect influence on variation, heredity has a direct influence, that is, the environment affects the reproductive system, which in turn leads to the variation.51 But this was very much Lamarck’s position too, Meyer contends, because Lamarck would never have questioned that the natural conditions and the acquired habits have anything more than an indirect influence on variation through the reproductive system (64). Ultimately, Meyer finds, the only difference between Darwin and Lamarck is one of emphasis, with Darwin stressing the role of the reproductive system and Lamarck the role of the environment (67).
Although Darwin laid great weight on the role of inheritance and the reproductive system, Meyer insisted that his idea of the struggle for existence commits him to giving no less importance to the environment. “This new name [struggle for existence] comprises what one would otherwise call dependence of the organism on climate, nourishment, life’s dangers and opportunities.” (66) What Meyer suggests here is a complete revision of Darwin’s theory, according to which one source of variation would be the struggle for existence itself. Although Darwin had treated variation and the struggle for existence as independent variables, Meyer wants to connect them, proposing that the struggle for existence should be a major source of how natural conditions affect heredity. If Darwin does the opposite, separating variation from the struggle for existence, Meyer contends, then he exposes his theory to a grave difficulty. For it means that whether a variation leads to adaptation is entirely a matter of accident or luck (80). If variation is strictly a matter of the laws of heredity, there is no reason to assume that variation will lead to greater adaptation; it will be possible for it to result in less adaptation or for it to be simply indifferent. It is indeed often the case, Meyer points out, that nature reproduces bad and indifferent variations, and for it to do so for generations (78). Furthermore, there is no reason to think that animals inheriting useful variations will survive in the struggle for existence, because they can be struck down by all kinds of circumstances, viz., disease, famine, competition, new changes in the environment.
On the whole, Meyer finds it hard to understand on Darwin’s premises how, without an enormous degree of luck, a new useful trait ever establishes itself in a species. That trait needs to be passed down and inherited by a future generation; but for that to happen a long list of conditions has to be fulfilled, viz., that the parent does not perish before it reproduces, that it mates with another parent having the same characteristics, that their offspring inherit the same traits, that the offspring survive, and so on (94).
All this goes to show, Meyer contends, that if we are to explain the origin of new species on Darwin’s theory, then we must take his guiding metaphor of natural selection literally (74–75). Darwin had based his theory on the analogy between artificial and natural selection, arguing that just as human beings can alter species through selective breeding, so nature herself could do so, and even in a more potent way by affecting the internal characteristics of an organism, or what Darwin called “the whole machinery of life”.52 The very idea of natural selection suggests, however, that there is some intelligent agent or design ensuring that useful variations will be chosen and adapt to their environments. Of course, Darwin does not want us to take that metaphor literally, and he goes to pains to explain that the selecting agency in nature is nothing more than the struggle for existence itself.53 But Meyer counters that only a literal reading of the metaphor explains the crucial fact that Darwin wants to explain: that natural selection results in the origin of a new species. Only the assumption of an intelligent agent or design removes the excessive role of chance in Darwin’s theory, which makes it unlikely that any useful variation is preserved and inherited. For Meyer, unlike Lange, teleology could not be so easily removed from the body of Darwin’s theory.
The great vice of Darwin’s theory, on Meyer’s final reckoning, consists in its grand speculations, its bold theorizing, for which there is hardly a shred of evidence. While Darwin avows empirical science in principle, he falls far short of it in practice. This is especially apparent, Meyer maintains, when Darwin fails to provide sufficient evidence for his central thesis: that it is possible for one species to evolve into another. Most of his hard evidence for change in species comes from his account of the domestic breeding of pigeons, where we learn that the more than 150 varieties of pigeons have a common ancestor in the rock pigeon. Yet all Darwin’s argument shows, Meyer declares, is that a pigeon is still a pigeon (71). All the effects of breeding are only different varieties of a single species. Darwin still has not demonstrated that there is a change of one species into another.
If Darwin has little evidence for an actual change in species, he has even less evidence, Meyer added, for his theory of descent, according to which all species have derived from a few primitive ancestors. While the geological record does show that there were once living on earth animals very different from those today, it does not demonstrate that they have grown out of one another, still less that we have grown out of them (56). Some naturalists think that Darwin’s theory of descent explains the great affinities in embryological and morphological structure; but these affinities too are only that: similarities in structure and geneology; they do not demonstrate that one species has actually evolved into another (96, 97).
Meyer’s model for the scientific treatment of the origin of species came from a very predictable source: Kant. The great sage of Königsberg was cited as the appropriate medicina mentis to be administered against the malady of speculation and excessive theorizing represented by Darwin. Meyer refers to, and cites at length, Kant’s 1785 essay on race,54 which had laid down severe limits on speculation about the origins of life. Kant had declared that the limits of natural explanation lie within possible experience, and that we transcend these limits as soon as we speculate about the origins of life itself. But Kant went even further, proscribing speculation about the origins of species themselves. Experience shows us evidence, he argued, only for how one creature came from a similar one; but to engage in speculation about how one species arose from another different one, well that was “an adventure of reason”. Darwin engaged in just such an adventure in speculating about the origin of species, Meyer implied, for he had failed to find sufficient evidence for an actual transformation in species, and for all species deriving from a few basic forms. All Darwin’s hypotheses about the origins of species exceed, Meyer wrote, “the standard of science” (92). Although hypotheses are perfectly permissable to explain facts, they cease to have value when there are no facts for them to explain; in Darwin’s case there really are no facts; all that we have are presumed facts to justify the hypotheses.
In coming to his verdict against Darwin, Meyer denied that he was applying stricter standards than Darwin himself, and he stressed that he and the English naturalist shared the same scientific ideals (90). Darwin too believed that scientific theories have to be tested by observation and experiment, and he too stressed that the problem of the origin of species has to be settled through these means. Meyer concedes that, to some extent, Darwin had succeeded in following his own guidelines. He had stayed within the limits of experience on several issues: in contesting fertility as a mark of a species, in showing that the degree of variability is much wider than assumed, and in consulting the geological record to support change of species. Still, he had gone well beyond experience in holding that species are transformable and that they are all derived from a few parent species.
Meyer’s criticism had raised, however, questions of its own. It was one thing to criticize Darwin for going beyond the available evidence; it was quite another to criticize him for speculating about that for which there could be no evidence at all. In other words, it is necessary to distinguish scientific speculation from metaphysics. It is a serious weakness of Meyer’s critique that he fails to make this distinction. This gave an opening for Darwin’s defence. It was possible to respond to Meyer’s criticisms: Darwin’s speculations are scientific; though they lack sufficient evidence, it is still possible, at least in principle, to provide it; and further experiment and observation could perhaps even confirm them. Darwin knew all too well he was pushing the envelope when it came to his speculations about the origin of species; he was well aware that they went beyond the available evidence; still, he believed that more evidence would become available with further research. And had this not happened, even by Meyer’s own reckoning? In any case, in the meantime, could his speculations not have value at least in providing direction for future enquiry?
It is a very tricky business setting the limits of knowledge. If we draw the boundaries too narrowly, we limit enquiry arbitrarily, which is dogmatism. If, however, we draw them too broadly, we admit metaphysics and its cousins, fantasy and enthusiasm. Meyer, it seems, had drawn the boundaries too tightly by forbidding even hypotheses or conjectures about the natural world. When he insisted that speculation has to be founded on already verified facts, he had virtually limited theory to what is already known. So scrupulous was Meyer that he had failed to see that a natural scientist does not play by the same rules as a philosophical sceptic. If Darwin had followed Meyer’s sceptical guidelines, he would never have written the Origin of Species. That was the ultimate refutation of his entire sceptical approach.
The last neo-Kantian to discuss Darwin in some depth and at some length was Otto Liebmann. He wrote a long essay on the theme ‘Platonismus und Darwinismus’ for his Zur Analysis der Wirklichkeit, which first appeared in 1876,55 and then several shorter essays on issues related to Darwin for his Gedanken und Thatsachen, which was published in 1899.56 Liebmann occupies his own niche in the neo-Kantian response to Darwin. Unlike Lange and Meyer, he represents the old Aristotelian tradition, the very tradition that Darwin intended to overthrow. Yet Liebmann’s aims were not counter-revolutionary; for his task was not to replace Darwinism with neo-Aristotelianism but to reconcile these warring parties, so that the English and Greek naturalists could live in harmony. This programme of reconciliation would be neo-Kantian in its own unique way, founded on the basis of Kant’s dualism between the natural and normative, the phenomenal and noumenal.
When Liebmann first turned to Darwinism in the early 1870s, he felt himself to be swimming against the current. Darwin’s theory was now so well-established in Germany that all discussions in the life sciences revolved around it. Liebmann wrote that “the great majority of the public”, “unless it had some religious prejudices”, had been converted to the new theory. He counted himself among the rare few who wanted to question it. While he did not want to contest Darwin’s theory on empirical grounds, he did want to point out its limits on philosophical grounds. The crucial question for Liebmann was whether Darwin’s theory could provide the basis for a materialist worldview. Were Büchner, Vogt and Haeckel right to see Darwin’s theory as confirmation for their own materialist creed? Liebmann was sceptical of those materialists who had made Darwin’s theory into their “philosophical gospel” (319). His critical objective was to limit Darwin’s theory strictly to the empirical realm, undermining any attempts to draw broader metaphysical conclusions from it.
Liebmann’s stance towards Darwin is almost the opposite of Meyer’s. While Meyer measures Darwin’s theory by the standards of empirical science and finds it wanting, Liebmann is concerned only with its metaphysical implications. Even if Darwin himself, forever the cautious scientist, was careful not to put forward metaphysical claims, his materialist apostles and acolytes in Germany were not so scrupulous; they saw Darwin’s theory as evidence for their materialist worldview. It is these materialists, not Darwin himself, that are Liebmann’s target. Unlike Meyer, then, Liebmann does not impugn the value of Darwin’s theory as empirical science. He does not think that Darwin’s theory sins against the standards of scientific method, and he even affirms that it is the best theory around about the origins of species. It was another great contribution of Darwin, Liebmann adds, to have provided so much evidence for the theory of transformation (347). While Darwin did not invent that theory—it had been around for millennia—he succeeded in providing it with an exact formulation (347). At the very least, any impartial reader of Darwin’s Origin of Species will find it highly illuminating (349). Indeed, it provides “the Ariadne’s thread through the labyrinth of the organic realm”. This does not mean, of course, that the theory is completely confirmed, that it is now incontestable doctrine. It is impossible to calculate the probability of Darwin’s theory, Liebmann notes, because there is still insufficient evidence for it, and there is still so much research to do (350). Nevertheless, because there is so much evidence in its favour, and because it seems to explain so many facts, we have good reason to adopt it as a regulative principle to guide further empirical research.
Nowhere is the contrast between Liebmann and Meyer more extreme than in their use of Kant in the origin of species debate. While Meyer invokes Kant as a talisman to banish all speculation about the origin of species, Liebmann cites him as an example of just such speculation, indeed as a forerunner of Darwin himself. Liebmann cites a long passage from Kant’s 1775 article ‘Von den verschiedenen Racen der Menschen’ to the effect that all species derive from a few prototypes.57 “Indeed, a true programme for Darwinism!”, he exclaims. If this were not enough, he then cites another passage from Kant’s Anthropologie where Kant hypothesizes that human beings could have emerged from apes.58 One is astonished to find, Liebmann exclaims, that Immanuel Kant, “the earnest idealist”, is a forerunner of “the notorious ape theory” that got Carl Vogt into so much trouble.
To examine the metaphysical implications of Darwin’s theory, Liebmann poses a single question: What is the relationship between Darwinism and Platonism? Are they compatible? Incompatible? Or complementary? By “Darwinism” and “Platonism” Liebmann means not the specific doctrines held by two historical individuals but two general worldviews (319). “Darwinism” stands for the attempt to explain life on mechanical principles, and more generally for the materialism of the Epicurean tradition. “Platonism” represents the attempt to explain life on idealist principles or on the basis of teleology. Behind these worldviews, on Liebmann’s account, are two contrasting views about the reality of universals. While the Epicurean is nominalist, regarding universals as mere concepts in the mind, the Platonist is a “formalist”, giving substantial reality to universals, whether above or beyond things. Liebmann uses the term “Platonism” in a broad sense, therefore, so that it includes any belief in the reality of universals. His own views commit him more to an Aristotelian than Platonic view about the reality of universals, because, as we shall soon see, his universals exist within animate things.
Liebmann’s central contention in ‘Platonismus und Darwinismus’ is that these apparently clashing worldviews are ultimately reconcilable, that Platonism must begin where Darwinism leaves off, because each is necessary for a full explanation of life. Liebmann is in no doubt whatsoever about the value and importance of providing, as far as possible, a mechanical and material explanation of life. To understand life, we have to know how it works and in what it consists, which means knowing its mechanical causes and its chemical components. Liebmann is highly critical, therefore, of the old doctrine of a “Lebenskraft”, an élan vital, because it places vital forces outside and beyond the general laws of nature (337–338). The laws of physics, mechanics and chemistry are universal, and they should apply to organic as well as inorganic matter. It was one of Darwin’s great merits, he recognizes, to have extended mechanical and material explanation beyond the traditional limits, and to have used them to account for the origin of species.
Nevertheless, despite his banishment of occult forces, Liebmann also believed that mechanical and material explanations have their limits. While they are indeed a necessary condition for the explanation of life, they are not a sufficient one. They can explain its mechanisms and material constituents; but they cannot explain its origins, how and why all these mechanisms and constituents came together to form a single living individual. The first causes of life, and its organic structure, remain inaccessible to mechanical and material explanation for the simple reason that such causes and such structures provide necessary conditions for any living phenomena. While natural science can explain any particular living phenomenon, it cannot account for why there are living phenomena in the first place (355). This is a metaphysical question which transcends the limits of all empirical science. In this respect Liebmann thinks that there is still some good sense to the old concept of a Lebenskraft after all. This concept serves to designate that aspect of life that is inexplicable according to mechanical and material explanation; it is that something more, that extra X, which mechanical and material explanation leave behind and fail to explain.
It was precisely with regard to this extra X, Liebmann contends, that Platonism enters the scene and goes beyond materialism and mechanism. This X is nothing less than the Platonic form, the universal inherent in a living thing that explains its constant structure and development. We need the idea of an organic form, Liebmann argues, to explain the difference between living and non-living things. For the organic, form is essential and necessary; for the inorganic, it is inessential and accidental (331). While the form of an organic thing grows out of it and is inherent in it, it is imposed upon an inorganic thing, which can take on a different form or structure. The form of an organic being stands for “all the characteristic, specific properties conceived together, such as habits, instincts, aptitudes, inclinations, degree of intelligence” (352). In stressing the idea of a substantial form as central to the concept of life, Liebmann went back immediately to the Leibnizian, and ultimately the Aristotelian, tradition, according to which the distinguishing feature of a living being is its characteristic form and energy (entelechy) to realize such a form (360). Liebmann saw no conflict between these traditions and Darwin’s theory, chiefly because Darwin was not concerned with the metaphysical question of the distinction between the living and non-living. It was in raising that more general question that the old “Platonic” tradition showed its abiding value for the explanation of life.
Although Liebmann was eager to defend Platonic and Leibnizian metaphysics, he was careful not to grant a constitutive validity to its basic concepts. The idea of a substantial form, of an entelechy, remained for him, as a good Kantian, strictly regulative. They are ideas that have a subjective validity for us to help us make sense of life; but we have no reason to believe that they are objectively true. Metaphysics is, as Liebmann put it, “not a science but only a postulate and problem” (356). It is one thing simply to deny a problem, as the positivists did, but quite another to recognize it and admit the impossibility of answering it. Implicitly but unmistakably, Liebmann took issue with Lange’s remark that metaphysics is only a poetic fiction, “Begriffsdichtung” (355–356). For Liebmann, teleology and organic form are more than poetry because they still have explanatory value, even if it is only regulative. Though Lange and Liebmann both stress the regulative status of teleology, they give a very different meaning to that status. Lange assumes that purposiveness will gradually and continually, though never completely, dissolve with the advance of mechanical explanations; for Liebmann, however, purposiveness is a completely irreducible and necessary concept, an indispensable device of the human understanding in coming to grips with organic phenomena.
Though bold and ingenious, Liebmann’s reconciliation strategy has problems of its own. While Meyer assumes there is no distinction between science and metaphysics. Liebmann presupposes that there can be a rigid and absolute borderline between them. But is this possible? Does not a scientific theory like Darwin’s have profound metaphysical implications? And is this not the reason why his theory is so important? Arguably, Liebmann never fully understood or appreciated the metaphysical implications of the Darwinian programme. It was a central thesis of Darwin’s theory that varieties are “incipient species”, that organic form grows and develops from natural selection and the struggle for existence. The net effect of such a theory is that the concept of a substantial form or entelechy is redundant for explaining life.
In going back to the Aristotelian and Leibnizian traditions, Liebmann was reinvoking the very tradition of fixed species that was Darwin’s chief target. The Linnaean system, which Darwin had set out to vanquish, is profoundly Aristotelian, holding that a species is a concrete universal. In Origin of Species Darwin had explicitly taken issue with the Linnaean view that the species or genus is prior to living phenomena, not derivative from them.59 The Linnaean system did not give the true causes of living phenomena precisely because it focused on formal or structural features, which are not basic but derivative. According to Darwin, a true system of classification has to be geneological, showing the common origins and parents of the various species; their formal or structural features would be the product or effect of the genetic potential of these parents in the struggle for existence. Thus Darwin had replaced an intellectualist or “formalist” worldview with a genetic or historical one. It was this fundamental fact that Liebmann failed to appreciate, and that ultimately doomed his well-intended but misconceived attempt to reconcile Darwinism and Platonism.
In 1899 the weary and ageing Ernst Haeckel, now in his sixty-fifth year, published his last will and testament, Die Welträthsel.60 He called himself a child of the 19th century, and he saw its close as a fitting time to end his life’s work. Die Welträthsel was to be the final statement of his philosophy, the culmination of all his labours and reflections as a natural scientist.
Just as Haeckel wished, the book ended his career with a bang, giving him all the publicity and controversy that he could have ever wished. It sold 40,000 copies in its first year of publication, 400,000 by the time of the First World War. And, just as Haeckel expected, it aroused howls of protest and indignation. Die Welträthsel was one of the most aggressive statements ever of a scientific and naturalistic worldview. With all guns blazing, it charged the social, political and religious establishment, shooting down every dogma and sacred cow in sight. Now that Ernst Haeckel was leaving this world, he wanted to leave nothing of the old order standing behind him. The new world order of the 20th century had to be founded on a completely new scientific morality and religion.
Die Welträthsel was first and foremost an exposition of Haeckel’s scientific worldview, which he called “monism”. This is the doctrine that we would nowadays call “naturalism”, that is, the thesis that everything in the universe is explicable (at least in principle) according to natural laws. The antithesis and enemy of monism Haeckel calls “dualism”, that is, the doctrine that there are limits in principle to scientific explanation, limits set by life and the mind, which supposedly fall outside the sphere of nature and exist in a supernatural realm. Haeckel saw his monism as the philosophy of natural science, as the worldview confirmed by all the scientific developments of the 19th century, which could boast that it had achieved more in science than all centuries before it.
Such was Haeckel’s confidence in the progress of science that he believed it could solve all the outstanding “mysteries” or “puzzles” of the universe. According to Emil Du Bois-Reymond, an erstwhile friend of Haeckel’s and the president of the Academy of Sciences in Berlin, there are seven such puzzles: 1) the essence of matter or force; 2) the origin of motion; 3) the genesis of life; 4) the design of nature; 5) the origin of sensation; 6) the genesis of consciounsess and language; and 7) free will.61 Zealous and self-assured, Haeckel declared that natural science had already solved the first six of these, and that the seventh was not really a puzzle at all, because free will did not exist and could not be the object of scientific investigation (18–19). Seldom in the history of science has a major scientist expressed such extraordinary confidence.
But we have to place Haeckel’s arrogance in context. It was his reaction to the treachery and timidty of old friends and colleagues. They had all renounced their faith in science, and they were now seeing irresolvable mysteries where they had once seen answerable questions. Although Die Welträthsel was meant to be a philosophy for the future, the worldview of the coming 20th century, its author knew all too well that it was really a rear guard action, the last stand of an old-fashioned naturalist who now felt himself to be alone in the world. Haeckel’s book was written in self-vindication against his old friends and colleagues, who had once been proud naturalists themselves, but who had now renounced the errors of their mechanist ways and had become “dualists”.62 Rudolf Virchow (1821–1902), Karl Ernst Baer (1792–1876), Emil Du Bois-Reymond (1818–1896) and Wilhelm Wundt (1832–1920)—these were all old friends and colleagues of Haeckel, and they had conspired with him in their youth to create a world free of teleology and vital forces in embryology, physiology and psychology. But in their later years they had come to renounce their mechanical programme as unworkable. Haeckel saw them all as traitors to the scientific cause, which it was left for him alone to vindicate. Pointedly, Haeckel discusses all their cases as signal instances of premature despair and senility. Self-vindication appears in the very title of Haeckel’s work, which was his counter to Emil Du Bois-Reymond’s ‘Die sieben Weltraethsel’. Du Bois-Reymond meant his enigmas to be limits to monism, warning signs to an overambitious naturalism. Haeckel wanted to expose them as hollow, arbitrary and artificial limits to the progress of the sciences.
Besides a statement of Haeckel’s monism, Die Welträthsel was an attack on every aspect of dualism and the moral and religious interests behind it. Its chief target was “the three central dogmas of metaphysics”, that is, the beliefs in the existence of God, freedom and immortality (267). All these beliefs are incompatible with monism, Haeckel argued, because they presuppose the existence of some supernatural realm. All have been falsified by the advance of the sciences.
Science has shown that: 1) theism rests on anthropomorphism, the projection of human fantasies and wishes on reality; 2) freedom does not exist because everything happens of necessity according to natural laws; and 3) the soul is mortal because it depends on the brain and the body to exist. Monism is therefore atheistic, deterministic and “thanatistic” (Haeckel’s term for the doctrine of the mortality of the soul). Haeckel had little objection to calling monism “pantheism”, which he defined as the doctrine that God and the world are one and the same. Pantheism, he noted, had always been the worldview of modern science (333). But he pointedly reminded his readers of Schopenhauer’s remark that pantheism was just a polite term for atheism (336).
Regarding the great conflict between science and religion, reason and faith, which had emerged from the materialism controversy, Haeckel took a firm stand on behalf of science and reason. There was no middle path where reason could justify faith. The more we take scientific investigation to its limits, he argued, the more we find not only that there is no evidence for the beliefs in the existence of God, freedom and immortality, but that the evidence actually goes against these beliefs, which can be shown to be simply false. Hence Haeckel is uncompromising that there can be no compromise: the old faith has to go, and it is high time for people to learn to live without the old gods. Faith, if it is incapable of scientific verification, is nothing more than superstition (348). While Haeckel readily conceded the moral and practical value of religious faith, he still insisted that such belief be based on reason. Rather than the church, there would now be “a palace of reason”, which would preach no longer the old trinity of father, son and holy ghost but the new trinity of truth, goodness and beauty (388).
Not the least provocative side of Die Welträthsel was its attack on neo-Kantianism itself. Haeckel was highly critical of the limits that Kant had placed on the mechanical explanation of life. Little could Kant have foreseen that “the Newton of the blade of grass” would appear in Charles Darwin, who had now revealed that mechanism really could explain the origin of life (301). Kant’s worst mistake, however, was his dualism, and especially his attempt to rescue the beliefs in God, freedom and immortality through practical reason (402). What Kant did not permit in the realm of theoretical reason—moral and religious faith—that he sneaked in through the back door of practical reason. For Haeckel, the distinction between theoretical and practical reason was just another dualism, a sneaky kind of dualism to preserve moral and religious faith. The faulty assumption behind Kant’s attempt to rescue these beliefs, Haeckel argued, is that they are neither demonstrable nor refutable, that is that the evidence is neither for nor against them. But the advance of the sciences has unearthed mountains of evidence against these beliefs, and it has shown them to be simply false. In attempting to justify these beliefs in practical terms, the neo-Kantians have shown themselves to be out of touch with the sciences. The neo-Kantian movement, Haeckel claimed, was largely based on this failed strategy (403).
Since Haeckel found the respect for Kant among the neo-Kantians grossly exaggerated, he proceeded to demolish their idol in a long polemical footnote (453–455, n.11). Kant’s lack of training in the medical sciences, his lack of experience with women, his failure to travel beyond the outskirts of Königsberg, all these showed the limits of his mental horizons. Was this the kind of philosopher who should be taken as the philosophical authority for the new century?
In advancing the cause of a scientific naturalism, and in insisting that the old dogmas had to go, Haeckel resembles nothing more than the old materialists of the 1850s. Die Welträthsel seems to be the latest materialist manifesto, a replacement for Büchner’s Kraft und Stoff, which was now beginning to look dated after its 20th edition. It was not surprising that Haeckel’s contemporaries saw his book in just this light. To the more elderly among them, Die Welträthsel was a nasty blast from the past, a throwback to the days of the materialism controversy. Yet it is important to see that Haeckel struggled to dissociate himself from the old materialists (23). After all, they knew nothing about Darwin, and the sciences had advanced mightily since their day. More importantly, Haeckel insisted that monism is not materialism. While materialism denies the existence of mind and dissolves the universe into a swirl of “dead atoms”, monism affirms the existence of the mind and maintains that matter consists in living forces. Haeckel then went on to identify his monism with Spinoza’s philosophy, according to which mind and body are distinct attributes of one and the same thing.
Yet the identification with Spinoza was something of a smokescreen, disguising the truly materialist dimension of Die Welträthsel. Haeckel had defended some defining materialist doctrines in his book, more specifically, the theory that the soul is nothing more than “a collective name for a sum of brain functions” (236). He thus undertook the classic materialist strategy of reducing the mental down to the physical. Such theories and strategies are hardly Spinozist, however. According to Spinoza’s monism, the mental and physical are equal and independent attributes of a single infinite substance, so that neither attribute is more real or fundamental than the other. We can see the whole universe from an ideal or real, mental or physical perspective; but we must not “mix attributes”, that is, make one reducible to another, given that both kinds of attributes are self-sufficient and independent.
There was, however, another kind of monism implicit in Die Welträthsel, a less materialist monism that came closer to vitalism, that is, the doctrine that everything in nature is alive and an expression or manifestation of life. For Haeckel, true to the vital materialist tradition, saw matter not as inert extension but as active living force, and he held that feeling and volition could be ascribed to the activity of all atoms.63Yet Haeckel did not develop this line of thinking, which would have brought him closer to Leibniz and the philosophy of identity of Schelling and Hegel. In the end, Haeckel never resolved the tension in his philosophy, which wavered between a complete materialism and a vitalistic monism. As we will now see, his neo-Kantian critics were relentless in pointing out this tension.
Given that Haeckel made a target of the neo-Kantians, it should not be surprising that they responded in kind. There were two major neo-Kantian polemics against Die Welträthsel, both published in 1901: Erich Adickes’ Kant contra Haeckel; and Friedrich Paulsen’s ‘Ernst Haeckel als Philosoph’, which appeared as part of his Philosophia Militans.64 Both Adickes and Paulsen understood their polemics to be critiques of “natural scientific dogmatism”, that is, the uncritical attempt to base metaphysics on natural science. This was to strike at the central nerve of Haeckel’s philosophy, which claimed to be the philosophy of natural science. For the neo-Kantians, there is no such philosophy.
From a philosophical standpoint, Paulsen’s polemic is a disappointment. It targets Haeckel’s manner of thinking more than any of his ideas. The professed aim of his tract is to show that “Haeckel is not to be taken seriously as a philosopher” (125). Paulsen deplores Haeckel’s tendentious reasoning, and his superficiality, ambivalence and confusion, which makes it difficult to ascribe any definite doctrine to him. He especially despises Haeckel’s dogmatism, which makes him confident that he has completely solved problems which he has not really begun to investigate. Rather than examining the views of others in depth, Haeckel passes judgement on them without having really studied or understood them. Haeckel’s worst sin, however, is that he does not fully recognize and appreciate the problems that he claims to solve (131).
While Haeckel is indeed guilty of all these sins, Paulsen’s own polemic does not really take the discussion any further at all. So, arguably, it is Paulsen who does not take seriously the problems at stake. However sloppy and obnoxious Haeckel’s reasoning, he still puts forward serious contentions to which any neo-Kantian worth his salt should respond. We want to know, for example, Paulsen’s response to Haeckel’s claim that Kant’s distinction between theoretical and practical is untenable. Rather than tackling this important challenge, Paulsen spends his, and his reader’s, time and energy showing that Haeckel was a poor Kant scholar. But would anyone have ever thought otherwise? Who would read Haeckel for his Kant scholarship?
At its close Paulsen confessed that he wrote his polemic in a fit of indignation. He was incensed that a public intellectual like Haeckel could be so dogmatic and arrogant on such a flimsy basis. Sometime afterwards, however, Paulsen added a postscript, which examines Haeckel in a much cooler light and in a more generous spirit. He now gives credit to Haeckel for fighting for Darwinist ideas when they were new in Germany and when they were received with hostility and derision. This explains some of Haeckel’s provocative style, which was simply responding to his enemies in kind. In this more reflective mood Paulsen also makes his one truly incisive comment about Haeckel’s philosophy. He notes the deep tension in Haeckel’s monism. On a superficial level, it is materialism pure and simple, a doctrine on par with Büchner’s and Vogt’s, though Haeckel lacked the courage to admit it. Yet, on another deeper level, it is not materialism at all but organicism or vitalism, that is, the thesis that the inner core of all reality is alive. This is the import of Haeckel’s frequent statements that feeling and volition are inherent in all things, and that nothing is dead or inert. If the external nature of things consists in motion and extension, as the materialist insists, its internal nature consists in feeling and thought. This vitalistic monism put Haeckel in the tradition of Spinoza, Bruno and Goethe, and now and then he justifiably felt a solidarity with them. Had Haeckel followed through this tendency of his thinking, Paulsen argues, he would have come to conclusions like his great contemporary Theodor Fechner,65 who saw all reality as alive. Yet Haeckel never developed this side of his thinking, and instead he lapsed back into his materialism by reducing life itself down to something material (190).
Adickes’ polemic is very different from Paulsen’s. Rather than just attacking Haeckel’s intellectual style, Adickes focuses on the general issues and states his own position on them. Kant contra Haeckel is not simply a defence of Kant’s philosophy against Haeckel’s objections, and Adickes warns us that he does not accept everything in Kant (4). What he does take over from Kant is his critical epistemological standpoint, which he regards as fundamental for all modern philosophy. It is this standpoint that he will apply to assess Haeckel’s metaphysics. Once one adopts that standpoint, Adickes argues, the verdict on Haeckel’s book is clear: “Kantian criticism (or more generally: epistemological reflection) should have been the foundation for the whole work. But, of course, in that case, it would never have been written.” (14) For Adickes, Haeckel’s work was from start to finish nothing but dogmatic metaphysics—a new kind of dogmatism, of course, one that claimed to be based on natural science rather than pure reason, but a dogmatism all the same. Kant’s old sentence, we are told, applies perfectly well to Haeckel: “The dogmatism of metaphysics, that is, the prejudice to make progress without a critique of pure reason, is the true source of all disbelief contrary to morality, which is always very dogmatic.”66 (114)
No less than Paulsen, Adickes’ reads Haeckel’s book as a materialist manifesto. We can safely reject all of Haeckel’s evasions, dementis and equivocations, he maintains, because Haeckel is perfectly clear in adopting the defining materialist doctrine that the mental is reducible to the physical. There are three ways in which one can reduce the mental to the material: 1) making thought and feeling properties of matter, which it manifests under specific circumstances; 2) identifying thought and feeling with movements and brain processes; and 3) deriving thought and feeling as effects of matter, which is their cause. It is a sure sign of Haeckels’s materialism, but also evidence for his confusion, that he adopts all three of these reduction strategies (9–10, 21–23).
Given that Haeckel’s philosophy is materialism, it is vulnerable to all the objections that have been made against that doctrine. Adickes finds it remarkable that Haeckel has learned so little from the materialism controversy of recent memory. All the weaknesses that Lange exposed in the materialism of Büchner, Vogt and Moleschott apply mutatis mutandi to Haeckel. The most important of these objections is that there is no evidence for the existence of matter in the materialist’s sense, that is, an object that exists in space and time, having all the properties that we perceive it to have even when we are not perceiving it. All the evidence from physiology and psychology show how our cognitive processes condition and determine what we know, so that we cannot claim that the existence of matter is a simple given of our sense experience (35–39). Rather than saying reality in itself consists in matter, we should say the very opposite: “everything physical is derived from the psychic, matter is a product of our mind, existing only as a state of consciousness” (35; Adicke’s stress). This proposition, Adickes reminds his readers, is the result of “epistemological idealism”, which one now associates with Kant’s name (36).
Though Adickes thinks that Haeckel is naive and dogmatic for ignoring the challenge of Kant’s “epistemological idealism”, he does not think this alone stands as the final refutation of Haeckel’s metaphysics. While it is indeed fatal for Haeckel’s materialism, that is not the only aspect or interpretation of Haeckel’s philosophy. Adickes, like Paulsen, thinks that there is another secret vitalist or organicist side to Haeckel’s philosophy. This vitalism becomes apparent whenever Haeckel claims that feeling and desire are inherent in all matter.67
For this vitalist thesis, Adickes argues, Haeckel can find no confirmation through observation or experiment; it is just as much an act of faith on his part as the Christian faith in God and immortality. But once we stress this vitalist side of Haeckel’s philosophy, Adickes contends, we can make full sense of his professed Spinozism. For there are now two equal and independent sides to reality corresponding to Spinoza’s two attributes. There is an inner side, in which each thing has feeling and desire; and there is an outer side, in which it appears as nothing more than movement and extension. This would be an acceptable version of Spinoza’s dual attribute doctrine, because we could see one and the same universal substance from either an internal or external perspective. Though Adickes’ maintains that this doctrine is implicit in Haeckel’s book, he regrets that Haeckel failed to develop it because of his attraction to materialism. For Adickes, like Paulsen, Haeckel’s monism is a monster, a conflation of materialism with the vitalist philosophy of identity of Schelling and the Naturphilosophen.
Haeckel is so far from refuting Kant’s doctrine of practical faith, Adickes claims, that the old Kantian strategy of denying knowledge to make room for faith is as valid as ever (113). Had Kant lived through the materialism controversy, had he read Büchner’s Stoff und Kraft and Haeckel’s Welträthsel, he would have been astonished at how little people had listened to him. Kant would only have repeated what he said in the Kritik der reinen Vernunft: that beyond the world of our consciousness there is an empty space, and that whoever dared to leave the little island of experience for “the wide and stormy ocean of reality itself” could do so only on the little boat of faith (114). The existence of an unknowable thing-in-itself was for Adickes the inevitable result of Kant’s transcendental idealism, and it provided a refuge for the entire realm of faith. Adickes denies that Haeckel has provided anything like a refutation of the beliefs in God, freedom and immortality. Because these beliefs are about the transcendent, they stand above and beyond refutation as well as demonstration, and so we are left with an agnosticism for the theoretical powers of reason. The realm of faith for Adickes is as broad as whatever cannot be demonstrated or refuted through reason or experience; it therefore includes all metaphysics, not least of all Haeckel’s own metaphysics, which is as much a matter of faith as Christianity (88, 96–98). It is simply naive, Adickes argues, to think that these principles are the simple and straightforward result of experiment and observation, which never proves universality and necessity.
As much as Adickes defends Kant’s doctrine of practical faith, he gives it an interpretation that hardly could be called Kantian. What we believe is for Adickes a matter of individual choice and feeling, and its justification is entirely personal and pragmatic: that I as an individual cannot get through life without it. There is no element of morality in Adickes’ version of practical faith, no attempt to use the categorical imperative to justify the beliefs in God, freedom and immortality. The problem with Haeckel’s rejection of practical faith is not that he ignored its moral dimension but that he failed to see how important faith is to individuals. Who was Haeckel to deprive people of their faith in immortality and God when it gave them comfort against the blows of fortune? (95) Haeckel’s atheistic and materialistic worldview is no less an act of faith than Christian theism because it too goes beyond the limits of experience and therefore knowledge.
Adickes concludes his polemic with a brief account of why Haeckel’s book has become so popular (115–129). He finds four reasons: 1) because people nowadays overestimate the powers of natural science; 2) because there is a philosophical need for a comprehensive worldview; 3) because of a trendy radicalism in all intellectual circles; and 4) because of an increasing anti-clericalism and anti-Christian tendency among intelligentsia. It was a plausible and exhaustive account of the reasons for Haeckel’s success. But it leaves the reader wondering whether Haeckel, despite all Adickes’ polemics, had won after all. From Adickes diagnosis of his success, it is easy to understand that the Zeitgeist was in Haeckel’s favour. All these were indeed reasons why neo-Kantianism would prove less popular in the new century.
1 John Theodore Merz, A History of European Thought in the Nineteenth Century (Edinburgh: William Blackwood & Sons, 1904–1912), I, 251, n.4.
2 Darwin to Wilhelm Preyer, March 1861, The Life and Letters of Charles Darwin (New York: Appelton, 1986), II, 270.
3 As cited in Alfred Kelly, The Descent of Darwin: The Popularization of Darwinism in Germany 1860–1914 (Chapel Hill, NC: University of North Carolina Press, 1981), p. 23.
4 Of late, there has been much research on Darwin’s reception and influence in Germany. See Mario Di Gregario, ‘Under Darwin’s Banner: Ernst Haeckel, Carl Gegenbaur and Evolutionary Morphology’, and Dirk Backenköhler ‘Only Dreams from an Afternoon Nap? Darwin’s Theory of Evolution and the Foundation of Biological Anthropology in Germany 1860–1875’, in The Reception of Charles Darwin in Europe, eds Eve-Marie Engels and Thomas F. Glick (London: Continuum, 2008) I, 79–97, 98–115; Eve-Marie Engels, Die Rezeption von Evolutionstheorien im 19. Jahrhundert (Frankfurt: Suhrkamp, 1995); Lynn Nyhart, Biology Takes Form: Animal Morphology and the German Universities 1800–1900 (Chicago, IL: University of Chicago Press, 1995), pp. 105–142; William Montgomery, ‘Germany’ in Comparative Reception of Darwinism, ed. Thomas F. Glick (Austin, TX: University of Texas Press, 1972), pp. 81–115; P.J. Weindling, ‘Darwinism in Germany’, in The Darwinian Heritage, ed. David Kohn (Princeton, NJ: Princeton University Press, 1985), pp. 685–698; and Andreas Daum, Wissenschaftspopularisierung im 19. Jahrhundert (Munich: Oldenbourg, 2002), pp. 65–84, 300–324, 359–369. See also the study by Alfred Kelly cited in note 3.
5 Robert J. Richards has recently argued that we have reason to correct our understanding and to bring it more in line with Haeckel’s interpretation. See his The Meaning of Evolution (Chicago, IL: University of Chicago Press, 1992), pp. 84–90.
6 See Ernst Haeckel, Gemeinverständliche Vorträge und Abhandlungen aus dem Gebiet der Entwicklungslehre, Zweite Auflage (Bonn: Emil Strauß, 1902), I, 1–34. On Haeckel, see above all Robert J. Richards, The Tragic Sense of Life: Ernst Haeckel and the Struggle over Evolutionary Thought (Chicago, IL: University of Chicago Press, 2008).
7 Haeckel, Vorträge und Abhandlungen, I, 29–30.
8 Robert Chambers, Natürliche Geschichte der Schöpfung des Weltalls (Braunschweig: Vieweg, 1851), trans. Karl Vogt; a second edition appeared in 1858.
9 Chambers, Vestiges of the Natural History of Creation (London: Churchill, 1844). The work, which went through many editions, originally appeared anonymously.
10 On the materialists’ reception of Darwin, see Frederick Gregory, Scientific Materialism in Nineteenth Century Germany (Dordrecht: Reidel, 1977), pp. 175–188.
11 Gregory, Scientific Materialism, p. 175.
12 See Charles Darwin, Über die Entstehung der Arten im Thier und Pflanzenreich durch natürliche Züchtung (Stuttgart: Schweizerbart, 1860). Bronn added a critical appendix, ‘Schlusswort des Übersetzers’, pp. 495–520, which was widely read and important for the early reception of Darwin. On Bronn, see Richards, Tragic Sense of Life, pp. 474–478, and Nyhart, Biology Takes Form, pp. 110–117. Because Darwin disliked the appendix, and because many saw it as interfering with the reader’s own judgement, a new translation was undertaken by Viktor Carus, Über die Entstehung der Arten im Thier und Pflanzenreich durch natürliche Züchtung (Stuttgart: Koch, 1872). All references to Darwin’s work in this chapter will be to the first edition, On the Origin of Species (London: John Murray, 1859).
13 Weindling, ‘Darwinism in Germany’, p. 686.
14 As cited in Richards, The Tragic Sense of Life, p. 100.
15 Friedrich Albert Lange, Geschichte des Materialismus, 2nd edn. (Iserlohn: Baedeker, 1873–1876), II, 240.
16 Kelly, Descent of Darwin, p. 21.
17 Kelly, Descent of Darwin, p. 21.
18 Otto Liebmann, ‘Platonismus und Darwinismus’, in Zur Analysis der Wirklichkeit, 3rd edn. (Straßburg: Trübner, 1900), pp. 318–319.
19 Kelly, The Descent of Darwin, p. 21.
20 Friedrich Albert Lange, Die Arbeiterfrage in ihrer Bedeutung für Gegenwart und Zukunft (Duisburg: Falk & Volmer, 1865), pp. 7–55. The first chapter, which contains long citations of Darwin’s Origin, is entitled ‘Der Kampf um das Dasein’.
21 Friedrich Albert Lange, Geschichte des Materialismus und Kritik seiner Bedeutung in der Gegenwart (Iserlohn: J. Baedeker, 1866), pp. 398–409.
22 Friedrich Albert Lange, Geschichte des Materialismus und Kritik seiner Bedeutung in der Gegenwart, Zweite Auflage (Iserlohn, J. Baedeker, 1875), pp. 240–284. Lange kept the original discussion from the 1866 edition, which appears on pp. 241–253.
23 All references to Lange, Geschichte des Materialismus in parentheses are to the second edition.
25 Lange, Geschichte des Materialismus (2nd edn), I, 23.
26 Darwin, The Descent of Man and Selection in Relation to Sex (London: John Murray, 1871).
27 Darwin wrote at the close of Chapter 3 of Origin of Species: “When we reflect on this struggle, we may console ourselves with the full belief, that the war of nature is not incessant, that no fear is felt, that death is generally prompt, and that the vigorous, the healthy, and the happy survive and multiply.” Origin of Species, p. 79.
28 See Lange, Geschichte des Materialismus, II, 58, 60.
29 See Engels to Lange, March 29, 1865, in Friedrich Albert Lange: Über Politik und Philosophie, Briefe und Leitartikel 1862–1875, ed. Georg Eckert (Duisburg: Braun Verlag, 1968), pp. 79–83.
30 Friedrich Albert Lange, Die Arbeiterfrage. Ihre Bedeutung für Gegenwart und Zukunft. Vierte Auflage (Winthur: Bleuler, Hausheer & Cie, 1879), pp. 217, 225, 227, 234–235. Great changes were made in later editions of this work. It is possible that Lange made this reply by the second edition, though this has not been available to me.
31 On Vogt’s complex views about species, see Gregory, Scientific Materialism, pp. 175–178.
32 Although it is not explicit, Lange seems to be responding here to Bronn’s objection, set forth in the widely read appendix to his translation of Origin of Species, that variation would result in a chaos of intermediate forms, where there would not be distinct groups. See Bronn, ‘Schlusswort des Übersetzers’, pp. 503–505.
33 Ernst Haeckel, Die Radiolaren (Rhizopoda Radiara). Eine Monographie. (Berlin: Georg Reimer, 1862), 2 vols. Though Lange does not explicitly cite this book, he was well-read in Haeckel’s work, which he cites often in the notes to this chapter. Lange refers specifically to Haeckel’s theory of individuality from Haeckel’s Generelle Morphologie der Organismen (Berlin: Reimer, 1866), I, 265ff.
34 See Darwin, Origin of Species, p. 413.
35 On the reaction to Darwin among these thinkers, see Nyhart, Biology Takes Form, pp. 105–142. Lange endorses the views of Kölliker and Nägeli, Geschichte des Materialismus, II, 262–263.
36 Lange cites Ernst Haeckel, Natürliche Schöpfungsgeschichte, Vierte Auflage (Berlin: Reimer, 1873), p. 373
37 See Meyer, ‘Die Rangordnung der organischen Wesen’, in Philosophische Zeitfragen, Populäre Aufsätze (Bonn: Adolph Marcus, 1870), pp. 104–119, esp. 105–107.
38 See Jürgen Bona Meyer, ‘Der Darwinismus’, Preussische Jahrbücher 17 (1866), 272–302, 404–452. In 1866 Rudolf Suchsland drew this review to Darwin’s attention, arguing that Meyer had misunderstood Darwin at one point because of the Bronn translation. See Suchsland to Darwin, April 2, 1866, in The Correspondence of Charles Darwin, ed. David Burkhardt et al. (Cambridge: Cambridge University Press, 2004), XVII, 111. Unfortunately, the enclosure containing the passage from the review is lost, so it is not clear how Suchsland thought that Meyer misunderstood Darwin.
39 ‘Die Entstehung der Arten. Der Darwinismus’, in Jürgen Bona Meyer, Philosophische Zeitfragen. Populäre Aufsätze (Bonn: Adolph Marcus, 1870), pp. 39–103. This chapter is in large parts a revised version of the original article in the Preussische Jahrbücher. All references in parentheses are to this later version.
40 George Cuvier, La Régne animal distribué d’après son organisation (Paris: Déterville, 1817), I, 20.
41 Meyer cites the opinion of Mattheus Schleiden from his Ueber den Materialismus der neueren deutschen Naturwissenschaft (Leipzig: Engelmann, 1863), p. 10n.
42 Carl Vogt, Vorlesungen über den Menschen (Gießen: Ricker, 1863), II, 269. The entire passage is cited by Meyer, pp. 48–49.
43 Darwin, Origin of Species, p. 257.
44 Darwin, Origin of Species, p. 248
46 On Darwin’s methodological guidelines, see C. Kenneth Waters, ‘The Arguments in the Origin of Species’ and David L. Hull, ‘Darwin’s science and Victorian philosophy of science’, in The Cambridge Companion to Darwin, second edition, eds Jonathan Hodge and Gregory Radick (Cambridge: Cambridge University Press, 2009), 120–146, 173–196. According to Waters, the entire structure of the Origin of Species revolves around Herschel’s theory of explanation.
47 Darwin, Origin of Species, p. 10.
48 Darwin, Origin of Species, pp. 8, 82, 133–134.
49 Darwin, Origin of Species, pp. 42–43. Cf. p. 8.
50 Darwin, Origin of Species, p. 13.
51 Darwin, Origin of Species, pp. 133–134.
52 Darwin, Origin of Species, pp. 83–84.
53 Darwin, Origin of Species, pp. 467–468.
54 Kant, ‘Bestimmung des Begriffs einer Menschenrace’, AA VIII, 89–106. This essay was first published in the Berlinische Monatsschrift VI (1785), 390–417.
55 Otto Liebmann, ‘Platonismus und Darwinismus’, in Zur Analysis der Wirklichkeit (Straßburg: J. Trübner, 1900), 3rd edition, pp. 317–361. All references in parentheses are to the third edition.
56 Otto Liebmann, ‘Idee und Entelechie’, and ‘Organische Natur und Teleologie’, in Gedanken und Thatsachen (Straßburg: J. Trübner, 1899), I, 89–121, 230–275.
57 Immanuel Kant, ‘Von den verschiedenen Racen der Menschen’, AA II, 427–444. This article first appeared in an announcement for Kant’s lectures on physical geography in the Summer Semester, 1775. Von den verschiedenen Racen der Menschen zur Ankündigung der Vorlesungen der physischen Geographie im Sommerhalbenjahre 1775 (Königsberg: Hartung, 1775).
58 See Immanuel Kant, Anthropologie in pragmatischer Hinsicht AA VII, 327–328n.
59 Darwin, Origin of Species, p. 413.
60 Ernst Haeckel, Die Welträthsel (Bonn: Emil Strauß, 1899). All references in parentheses are to this edition. There is an old English translation of this work by Joseph McCabe, The Riddle of the Universe (New York: Harper & Brothers, 1900), though it is of questionable reliability. Even the translation of the title is misleading. Haeckel’s title is pointedly in the plural, a reference to Emil Du Bois-Reymond’s Die Sieben Welträthsel.
61 Emil Du Bois-Reymond, ‘Die Sieben Weltraetsel. Nachtrag’, Monatsbericht der Koeniglich- Preussischen Akademie der Wissenschaften (8 Juli 1880), 1045–1072. Reprinted in Über die Grenzen des Naturerkennens. Die sieben Welträthsel, Zwei Vorträge (Leipzig: Veit, 1882), pp. 83–110.
62 Haeckel’s reaction against his former allies and colleagues begins in his Freie Wissenschaft und freie Lehre (Stuttgart: E. Schweizerbart, 1878), which was a critique of Ernst Baer, Emil Du Bois-Reymond and his old teacher Rudolf Virchow.
63 See Haeckel, Die Welträtsel, pp. 206, 259.
64 Erich Adickes, Kant contra Haeckel: Erkenntnistheorie gegen Naturwissenschaftlichen Dogmatismus (Berlin: Reuther & Reichard, 1901); and Friedrich Paulsen, ‘Ernst Haeckel als Philosoph’, in Philosophia Militans (Berlin: Reuther & Reichard, 1901), pp. 119–192.
65 Gustav Theodor Fechner (1801–1887) was the author of two books expounding a vitalist view of the universe, Nanna: oder Über das Seelenleben der Pflanzen (Hamburg: Voß, 1848) and Zend-Avesta: oder Über die Dinge des Himmels und des Jenseits vom Standpunkt der Naturbetrachtung (Hamburg: Voß, 1851). The former work maintains that plants have feelings and desires; the latter holds that even material things are animate.
66 KrV B xxx. My translation follows Adickes’ inexact citation.
67 See, for example, Haeckel, Die Welträthsel, pp. 182–183, 254, 259.