Chapter Six—
Orthodoxy

The twentieth century brought forth ominous threats to the intricate fortress of Darwinian thought. Mounting challenges came from science, philosophy, and theology. In science, they came primarily from new developments in biological thought, mainly from the general principles of genetics, the most radical branch in experimental biology. Although it had influential spokesmen and was in command of powerful arguments, the opposition lacked inner unity sufficient to present a formidable threat to the reign of Darwinism. The fragmentation of opposing forces worked in favor of Darwinian purists, deeply engaged in a massive effort to preserve and consolidate the orthodox views.

The purists divided the more recent advances in experimental biology into two groups: those that could readily be integrated, as collateral material, into Darwinian thought; and those that must be rejected because of their incompatibility with Darwin's theory. They accepted modern genetics, for example, only insofar as it enhanced Darwin's orientation by helping explain certain phenomena of heredity, a topic to which the English naturalist did not give sufficient attention. They viewed acceptable contributions of modern biology as elaborations of ideas Darwin had suggested in the first place. While agreeing among themselves in principle, the leading guardians of Darwinian orthodoxy differed in their choice and interpretation of new ideas that could be integrated into Darwinian thought.

Three biologists were widely heralded as the most dedicated defenders of Darwinian orthodoxy. Kliment Timiriazev became well known

through his efforts to present Darwinism as a stronghold of Newtonian science and through his sweeping and emotionally charged crusade against the developments in contemporary biology that stood in open conflict with Darwin's ideas. Mikhail Menzbir conducted a gentle but broadly based defense of Darwin's theory and presented a popular overview of developments on the Darwinian front. A leading ornithologist, he buttressed Darwinism with a strong ecological interest. Aleksei Severtsov was so much preoccupied with elaborating, refining, and generalizing Darwin's theoretical heritage that he showed little inclination to seek help from "unorthodox" developments in experimental biology. As the creator of a theoretical system of evolutionary morphology, he became well known, far beyond the boundaries of Russia.

Different in style of work, scholarly specialty, temperament, and philosophical involvement, Timiriazev, Menzbir, and Severtsov were united in a massive effort to interpret the rapidly expanding world of evolutionary biology from Darwinian positions. They dedicated their lives to Darwinian thought, protecting it from the inexorable forces of erosion and shaping it into an ordered body of scientific knowledge and into a grand strategy for the study of living nature. Their ideas and actions make up the main substance of this chapter.

K. A. Timiriazev:
Darwin's Russian Bulldog

Timiriazev enjoyed a great reputation as a pioneer in the study of photosynthesis, a champion of biological evolutionism, a popularizer of scientific knowledge, and an outspoken defender of academic freedom. With a flair for dramatic expression, he made the popularization and the defense of Darwin's theory integral components of the ongoing struggle for university autonomy, free science, and democratic politics. During most of his scholarly career, which began in the mid-1860s, he made the defense of Darwin's theoretical views the focal point of his writing and public lectures. No Russian scholar of his generation surpassed the scope and the intensity of his concern with Darwin's scientific contributions. He was the editor of an eight-volume collection of Darwin's works in Russian translation, published in 1907–9. Together with M. A. Menzbir, he produced one of the better Russian translations of the Origin of Species .

Timiriazev's view of Darwin was clear and simple. Darwin's theory, he thought, represented welcome opposition to every teleology and to every philosophy that relied on transcendental causation. He saw it as

the unchallengeable foundation for a unitary view of nature and fully agreed with Boltzmann's statement that Darwin's theory was the only salvation for philosophy. Darwin's theory, in Timiriazev's view, enhanced the ties between biology, on the one hand, and physics and chemistry, on the other. Darwinian rationalism, he argued, was a most powerful and distinctive cluster of ideas shaping the modern world view. Timiriazev did not hesitate to place the tag of vitalism on all the experimental studies of inheritance which he happened to regard as anti-Darwinian.

In his dedicated defense and extensive popularization of Darwin's scientific ideas, Timiriazev was inspired and guided by philosophical judgments of two great Western scientists: Hermann Helmholtz and Ludwig Boltzmann. In 1869, in the opening speech before the Congress of German Naturalists and Physicians held in Innsbruck, Helmholtz praised Darwin for showing that the blind laws of nature rather than the interference of a supreme intelligence account for the development of organisms.^[1] In a paper read before a gathering of the Vienna Academy of Sciences in 1886, Boltzmann noted that the nineteenth century will be remembered as a century of natural science, and that, as a century of natural science, it will be remembered for two great achievements: the full victory of the mechanistic view of nature and the triumph of Darwin's theory.^[2] Since biology benefited from both triumphs, it was, in a way, a symbolic expression of the century's most sublime achievements in science. In a sense, Darwinism was a high mark of the century because it covered the two basic attributes of the living world—its evolution and its physicochemical foundations. When Timiriazev protected Darwinism, he in effect protected an evolutionary theory built on Newtonian foundations.^[3]

At the beginning of the twentieth century Timiriazev was convinced that Darwin's scientific authority was stronger than ever before. Darwin's contribution, he argued, was not just another step in a long series of evolutionist developments in biological thought; on the contrary, Darwin opened a new era in the history of biology by dealing a fatal blow to the idea of antitransformism, the dominant view prior to 1859. At the time of the publication of the Origin of Species biological thought was dominated by the antievolutionism of Cuvier, Agassiz, and Owen, as well as by Lyell's efforts to discredit Lamarck's transformist ideas. The effort of É. Geoffroy Saint-Hilaire to fit biology into an evolutionary mold encountered such formidable enemies that it could not become part of established thought.^[4] Darwinism won the day—and wrought a

revolution in biology—not because it had a long list of ancestors but because it succeeded in identifying "evolution" with "progress," and because it rested on the principle of adaptation, the key to a realistic understanding of the "perfection, purposiveness, and harmony" of living nature. Timiriazev compared Darwin with Vico: Vico tried to transform history into natural history; Darwin succeeded in making natural history true history.^[5]

In another essay, devoted to the basic functions of plant physiology, Timiriazev gave a clear picture of his full allegiance to mechanistic biology:

To study the phenomena of plant life successfully, physiology does not need arbitrary suppositions that the sciences dealing with inorganic matter have rejected a long time ago. It needs no help from outmoded beliefs in the existence of a special organic substance. It needs descriptions and general laws applied to inorganic bodies. It does not need a special, elusive, and self-propelled force that ranks above the law of causality and above number and measure. The basic laws of physics meet its needs no less than those of the inorganic matter. Finally, it does not need to assume the existence of a universal metaphysical principle of purposeful development—the vitalist's last resort. As Darwin has shown, it is satisfied with the real historical process that guides the organic world to inevitable perfection and harmony. We have a full right to assert that, in its effort to explain the phenomena of life, plant physiology must study three categories of causes—chemical, physical, and historical. . . . Each category is dominated by a distinct general law that helps shape our world view, and each is associated with a leading figure in modern science. The three laws are: the law of the conservation of matter, the law of the conservation of energy, and the law of the transformation and unity of life. The three leading figures are Lavoisier, Helmholtz, and Darwin.^[6]

Timiriazev's unequivocal emphasis on the methodological superiority of physicochemical analysis of vital processes was a specific expression of an overarching belief in the unity of nature. As a plant physiologist, with photosynthesis as his central interest, he was a natural recruit for the idea of cosmic unity—and of the unity of science. The life of plants depends on photosynthesis, a complex process whereby chlorophyll harnesses solar energy to produce carbohydrates and other organic compounds necessary for the subsistence and growth of green plants. Photosynthesis, as Timiriazev saw it, represents the clearest possible example of the working of the law of the conservation and transformation of energy. A physical explanation of chemical substances holds the key to the understanding of the processes of life without resorting to an imaginary "vital force." In addition to reaffirming the physicochemi-

cal unity of nature, the law of the conservation of energy reinforces the mechanistic foundations of natural science. In his discussion of organic evolution as a specific expression of cosmic unity, Timiriazev depended primarily on a combination of philosophical discourse and poetic effusion.

In his defense and elaboration of Darwinian thought Timiriazev fought on several fronts: he repeatedly returned to Lamarckism for the purpose of showing the fundamental nature of its incompatibility with Darwin's theory, but he also fought the revived vitalism and the threats to Darwinism by modern orientations in experimental biology. He defended Darwinism by waging an uncompromising and bitter war on its enemies, both real and imagined.

Asking himself the rhetorical question, "What requirements must an evolutionary theory meet in order to be scientific?" he made his opposition to Lamarckism unequivocal:

[An acceptable theory] must (1) indicate the role of an evolutionary, or a historical, process in the transformation of species; (2) point out the natural factors that transform this process into progress, that is, into improvement in the adaptation of the organization of living forms to the conditions of existence; and (3) explain the apparent contradiction between the notion of the unity of organic nature as a whole and the presence of discontinuities within and between living groups of all orders. Darwinism is the only theory that meets these requirements. No other effort—not even Lamarckism—has met these standards in a satisfactory fashion.^[7]

Lamarck's idea of the direct influence of the environment on the transformation of living forms, according to Timiriazev, did not receive support from "convincing facts." In fact, modern research has fully rejected the notion of the primary role of use and disuse of organs in the adaptation of living forms to the environment—and in the acquisition of new heritable characteristics, the chief mechanism of organic evolution.

On another occasion Timiriazev was much more conciliatory. He wrote:

If Darwin spoke harshly about Lamarck, it was only in relation to his unfortunate effort to explain the evolutionary process by relying on the behavior of plants and animals, a criticism that has been justified by subsequent developments in science. From the very beginning, Darwin recognized the dependence of organic forms on environment—that is, he recognized the part of Lamarck's theory that has survived as an important contribution to

modern biology. Darwin's appreciation of this idea increased as time passed. Only a merging of this side of Lamarckism with Darwinism can solve the key problem of biology. . . . Many contemporary German neo-Lamarckians suffer from a misunderstanding of the interdependence of the two theories.^[8]

This citation has a double edge. In the first place, it expresses a view of the complementarity of Lamarckism and Darwinism, widespread among Russian biologists. This does not mean, however, that this complementarity was a topic of comprehensive and systematic discussion. Lamarckism existed primarily as a valuable, but little debated, corollary of Darwinism. In the second place, Timiriazev's clearly expressed distaste for the ideas of the German supporters of psycho-Lamarckism represented a fair expression of the general sentiment in Russia. Only isolated Russian biologists concerned themselves with the psychological aspect of evolution, and all firmly opposed the strong metaphysical bias of the more extreme German psycho-Lamarckians, led by A. Pauly and R. Francé.

In the resurgence of vitalism Timiriazev saw not only an unwelcome attack on the spirit of Newtonian science but also a deceitful effort to subordinate science to idealistic metaphysics. The rebirth of vitalism was more than an attack on the reigning orientation in contemporary science; it was an effort to limit the intellectual authority of science.^[9] Timiriazev viewed science as a unique approach to reality that would never reach the point of diminishing returns. The neovitalists, by contrast, saw biology, heavily committed to physicochemical analysis, as a science that had reached a point of diminishing returns and that could be saved only by a heavy reliance on metaphysics. In attacking the neovitalists, Timiriazev concentrated on their pessimistic view of the future of science. His scathing attack on the botanist I. P. Borodin, who welcomed the resurgence of vitalism, helped limit the spread of neovitalist ideas in the Russian scientific community.^[10] Timiriazev's optimism about the future of science was an expression of unlimited faith in physicochemical techniques in the study of life processes.

After 1900 Timiriazev made "the Mendelians and mutationists" the main targets of his war on "anti-Darwinism." The more the criticism of Darwin's theory grew in depth and in fervor, the more he clung to the unmodifid principles of Darwin's theory and the more uncompromising he became in his war on real and imagined enemies. In his criticism of the mutation theory he pursued two lines of attack: on the one hand, he argued that mutations are aberrations rather than regular components

of the natural course of evolution; on the other hand, he contended that Darwin did not ignore mutations and that de Vries and Korzhinskii learned about them from the first edition of the Origin of Species .^[11]

Mendel's followers troubled Timiriazev most because, in his opinion, they advanced the most pernicious arguments against Darwin's theory. In his criticism of Mendel's laws of heredity he asserted that evolutionary research needed most of all physiological experiments as a substitute for "a statistical record of observations."^[12] The claim of Mendel's followers that their genetic laws were universal did not meet with Timiriazev's approval. In contrast to popular opinion, Mendel contended that crossing does not produce either a "fusion" of alternative characters or a disappearance of individual characters. Without adducing empirical evidence to support his claim, Timiriazev argued that a fusion of characters was also possible, and that therefore Mendel's assertion did not constitute a universal law of nature.^[13] He quickly added that Mendel, "a wise man and an experienced scholar," did not intend to attribute universality to his discoveries.^[14] Timiriazev gave Mendel credit for conducting "a careful statistical study" of heredity which led to an empirical generalization in full agreement with Darwin's theory. He considered the fast-rising genetics only a minor partner in the family of biological sciences.

Obviously, Timiriazev tried to make it clear that he opposed Mendelians, not Mendel. In his opinion, the "anti-Darwinism" of the new genetics was the main reason for Mendel's fast-rising popularity. In Germany, he wrote, anti-Darwinism was both a by-product of the growing influence of "clericalism" and an expression of nationalism, a unique sign of anti-English sentiment.^[15] He was particularly angered by an English writer who in 1907 elevated Mendel to the ultimate heights of scientific achievement—a favorable comparison with Newton.^[16]

Whether he criticized mutationism or Mendelism, neo-Darwinism or neovitalism, Timiriazev made Darwinism part of a materialistic ontology of science, of a positivist orientation in epistemology, and of a firm devotion to scientific knowledge as a liberating social force. An exponent of positivist philosophy, he counted Auguste Comte among Darwin's leading forerunners.^[17] In protecting Darwinism Timiriazev also protected a view of science as the primary source of moral progress in the modern world. He undertook the task of popularizing the contents of Marcellin Berthelot's Science et morale, particularly the claim that from the seventeenth century on, science has been the only true

contributor to "the improvement of the material and moral conditions of social life."^[18]

To defend Darwinism, Timiriazev thought, was to be allied with a political ideology that saw the future of Russia in democratic institutions. He saw Darwinism as a bastion of rationalism and as the most powerful tool against metaphysical vestiges in modern scientific thought. In particular, it was the basic weapon in the war against neovitalism, a metaphysical orientation steeped in spiritualism and allied with a strong antiscientific movement.

Timiriazev's scorching attacks on the "enemies" of Darwinism did not evoke serious rebuttals. Powerful groups in and outside the academic world shared his total devotion to Darwin and his thought. He was a charismatic speaker, and everything he said at scholarly assemblies produced strong echoes in educated society. His claim that the triumph of Darwin's theory was a key factor in the rapid growth of natural science in Russia evoked approving responses of massive proportions. Much of his writing consisted of popular accounts of science as a cultural value of the first order. Darwinism, as he presented it, was the real force behind the developments that led to the victory of rationalism, historical outlook, and secular thought in modern Russian society. He benefited from his clear identification with the liberal professoriate, representing the dominant and most influential ideology in the scholarly community. Working in his favor was also the continued high respect for Darwin among the radical intelligentsia, including the most determined critics of the struggle for existence as a prime mover of organic evolution.

Timiriazev fought his enemies either by totally rejecting the scientific merit of their theoretical claims or by treating their work as inconsequential challenges to Darwin's scholarly achievement. His attacks were sweeping and acrimonious; his willingness to compromise was of the most evasive kind. For this reason his contemporaries remembered him primarily as a bitter enemy of all modern developments in biology that did not, in his opinion, follow Darwinian thought.

In 1894 M. M. Filippov, editor of Science Review, published a lengthy article criticizing Timiriazev's defense of Darwinism. He said that Timiriazev oversimplified the raging conflict in the scientific community by identifying all critics of Darwinian orthodoxy as anti-Darwinists.^[19] Filippov was essentially correct. To be admitted to the ranks of Darwinists, according to Timiriazev, a biologist must recognize the evolutionary

significance of Malthus's law, the indirect influence of the environment on the evolution of plants and animals, natural selection as a universal factor of organic transformation, and the evolutionary process as a pure product of external natural causes, unmarred by internal teleological considerations. Filippov, by contrast, claimed that Darwinism needed a broad reformulation that would recognize both the direct and the indirect influence of the environment, would treat the struggle for existence as one of many evolutionary factors (he placed particular emphasis on symbiotic coexistence of different life forms as a source of new species), and would make the idea of purposiveness an integral part of the evolutionary model. He directed particularly harsh remarks at Timiriazev's repeated efforts to view all criticism of natural selection as a flirtation with vitalism.^[20] Timiriazev, he thought, did injustice to Darwin by transforming his ideas into a dogma and by trying to preserve some of Darwin's less defensible suggestions.

Filippov asserted categorically that he was not part of an anti-Darwinian movement, and his published essays attest to the truthfulness of his claim. He wrote that without the scientific legacy of the founder of evolutionary biology, the study of life would not have reached the heights it occupied at the time of his writing. Biology, he added, could advance only by building upon, rather than by negating, Darwin's contributions.^[21] The future of biology was neither in N. Ia. Danilevskii's unfounded anti-Darwinism nor in Timiriazev's dogmatic Darwinism. In assessing the state of evolutionary thought in Russia, Filippov made one major error: he ignored the Russian echoes of the neo-Darwinian efforts to combine Darwinian natural selection with the primacy of internal causes of variation. He was closer to Lamarckism than to any other strand in contemporary evolutionary biology.^[22] As a free-lance writer, mainly on scientific themes, he did not pose a serious threat to Timiriazev, who decided not to be involved in yet another bitter debate. A brief but biting footnote to an article in Russian Thought was the extent of Timiriazev's rebuttal.^[23]

Timiriazev was not always ready to recognize the work of those who contributed to the popular literature on Darwinism as a positive force. For example, he took no note of M. A. Antonovich's Darwin and His Theory, published in 1896, most of which was previously serialized in the journal Russian Thought . Nor did he refer to Antonovich's "Theory of the Origin of Species," published in Sovremennik in 1864, one of the clearest and most laudatory early essays on Darwin's theory to be published in Russia. Antonovich's book covered important topics from the

history of Darwinism which were not previously discussed in Russia in a systematic fashion. It had two strong features: it traced the growth of Darwinian thought from the appearance of the Voyage of the Beagle to the series of studies that appeared after The Descent of Man ; and it provided special discussions of the reception of Darwinian ideas in England, Germany, France, the United States, and Russia—with every country accorded individual treatment.

In one important respect, Timiriazev's adherence to the theoretical substratum of Darwin's biology was somewhat ambivalent. He accepted the struggle for existence but did not give it a precise definition. He "solved" the dilemma simply by avoiding a direct confrontation with this unpleasant and tortuous task. By his own admission, he made a conscious effort to avoid any reference to the struggle for existence. This reluctance had an ideological rather than a scientific explanation: he echoed the opinion of the leading ideologues among the radical intelligentsia, who tried to reconcile Darwinism with social theories that regarded cooperation, rather than competition or conflict, as the prime mechanism of progressive evolution.

In his search for an acceptable notion of natural selection, Timiriazev received assistance from Thomas Huxley's essay "The Struggle for Existence," which he had helped translate into Russian.^[24] In this article, Huxley, in an obvious effort to erase the path leading from Darwin's theory to Social Darwinism, described the difference between the cosmic process of life in general and the ethical process which has dominated human society after its ascent to the higher rungs of evolution. As human society passes from a "natural" to an "ethical" state, natural selection also passes from conflict or struggle to cooperation. To talk about the struggle for survival is to talk about the "natural" phase in the evolution of human society. "The unfortunate expression 'struggle for survival' has nothing in common with the doctrine of morality, because human morality is built by the social structure—'by society'—rather than by the biological endowment."^[25] Or: "The theory of the struggle for survival was abandoned at the threshold of history; the entire rational and cultural activity of man is only a struggle against the struggle for existence."^[26] Neither Huxley nor Timiriazev worked hard to explain the origin and social dynamics of the ethical process; both made scientific concessions to alleviate the ideological pressure coming from many sources. This was one of the very few times that Timiriazev showed a willingness to modify the Darwinian legacy to satisfy the extrascientific pressures of the day.

While shifting the emphasis from conflict and struggle to cooperation, specifically in reference to human society, Timiriazev showed no inclination to abandon the Darwinian notion of natural selection as the basic mechanism of organic evolution. He continued to resist the arguments of critics who emphasized the practical impossibility of giving the notion of natural selection adequate empirical support. Admitting that the search for empirical verification of natural selection faced grave difficulties, he contended that solid steps in that direction had already been taken. As a specific case of natural selection in operation, he cited W. F. R. Weldon's biometric study of the differential adaptation of a small shore-crab (Carcinus maenas ), a denizen of Plymouth Bay, to waters with a low level of sediment and to waters with a high level of sediment.^[27] Timiriazev found it necessary to refute de Vries's claim that artificial selection did not play as important a role in the origin of new varieties of plants and animals as Darwin was predisposed to think. In his rebuttal of de Vries's view, Timiriazev leaned heavily on Luther Burbank's successes in effecting rapid changes in "almost all characteristics" of domestic plants on which experiments were made. Timiriazev particularly welcomed Burbank's open admission that in all his experiments he operated strictly from Darwin's theoretical positions.

Timiriazev's major contribution was in defending Darwin's theory at the time when it was much in need of a strong defense. He helped make Darwinism a high point in the growth of modern secular thought in Russia, and more clearly than any other Russian scientist, showed the unsurpassed proportions of Darwin's contributions to reunifying man with nature and to expanding the range of subjects open to scientific scrutiny. He contributed to making Russia a rare country that did not encourage the emergence of Social Darwinism as an ideological factor of serious consequence. Inasmuch as he tied his defense of Darwinism—and of the evolutionary point of view in general—to a relentless war on the key developments in contemporary experimental biology, his contributions to the advancement of modern biological thought in Russia were clearly negative.

M. A. Menzbir:
A Quiet Defender of Orthodoxy

In 1882, three years after graduating from Moscow University, Mikhail Aleksandrovich Menzbir (1855–1935) wrote two studies which opened two distinct avenues for his future scholarship. The Ornithologi -

cal Geography of European Russia, immediately accepted as a masterwork in zoogeography, started him on a distinguished career in the study of the ecological features and taxonomy of Russian birds. Going against the established practice in zoogeography, he divided the vast territory he studied into distinct regions by relying on faunistic rather than on geographical features. This study kept Menzbir close to the current work in natural history, which acquired massive proportions particularly after the founding of naturalist societies at all the leading universities. It brought quick and impressive rewards: in the same year he was appointed editor of the serial publications of the Moscow Society of Naturalists, a job he held until his death; two years later he was appointed docent at Moscow University, the institution with which he was affiliated most of his life. The second work was an essay commemorating the death of Charles Darwin, the first in a long series of publications Menzbir devoted to the scientific contributions of the founder of the evolutionary theory. Published in the popular journal Russian Thought, this article presented the main components of Darwin's theory, showing, in particular, the usefulness of the evolutionary orientation in ornithology. Unlike most of his Russian contemporaries, he made no objection to Darwin's reliance on Malthusian progressions.^[28]

In the scope and fervor of his defense of Darwin's scientific legacy, Menzbir was Timiriazev's equal. The two men, however, did not fit the same pattern of scholarly engagement. They brought different backgrounds to their involvement in Darwinian studies. Timiriazev, a plant physiologist, brought an awareness of the importance of physiology to the study of evolution, as well as a conviction that physicochemical analysis should be the primary method of physiology. Menzbir, by contrast, came from a background that combined zoogeography and systematics, a common combination at this time. His ornithological studies appealed to bird lovers, ecologists, and taxonomists alike; most of them stayed at a low level of theoretical considerations.

Both Timiriazev and Menzbir addressed most of their writings on evolution to two audiences: professional biologists and interested laymen. The modes of their writing were quite different. Timiriazev was particularly eager to show the intricacies of Darwin's construction of the conceptual base of his theory of evolution. Menzbir was much more interested in showing how evolution, as Darwin interpreted it, worked in real life. Timiriazev used empirical data to illustrate the intricacies of the general theory of evolution; Menzbir used evolutionary theory to trace transformation processes in specific subdivisions of the ani-

mal universe. There were other differences as well. Unlike Timiriazev, Menzbir was calm, careful, and systematic in reacting to "unorthodox" views in evolutionary theory. In his concessions to the new discoveries in experimental biology he was more gracious than Timiriazev, and his arguments did not transgress the limits of academic propriety. In one important respect the two scientists acted as one: both contended that Darwin's theory of evolution needed only clarification and refinement to be fully established as the primary factor of organic evolution. Despite the measured tone of his rebuttals, Menzbir stuck firmly to the idea that all new developments in biological theory must be judged by their contributions to the universal appeal and revolutionary significance of Darwin's science.

There was another pronounced difference between Timiriazev and Menzbir. Timiriazev was very close to Darwin: he cited him profusely, he stuck closely not only to the substance but also to the style of Darwin's scientific argumentation, and he approached Darwin's theory as a symmetrical, explicit, and integrated system of thought. Menzbir was much less prone to make direct references to—particularly to cite—Darwin: in some essays on evolution, written in the Darwinian spirit, he did not make a single direct reference to Darwin. His Darwinism was selective, asymmetrical, and rather personal. He ignored most of Darwin's suggestions for future exploratory work and his views on more sensitive problems of methodology. Yet in his dedication and basic theoretical commitments Menzbir was one of Darwin's most loyal and enthusiastic followers.

Menzbir's loyalty to Darwin's theory made him a staunch defender of the common origin of man and animal. In 1889 R. Virchow, in a speech at the Congress of German Anthropologists held in Vienna, made a plea for dissociating anthropology from evolutionary ideas and from Darwinian theories. He justified his action on the ground that all efforts to produce a scientific explanation of the origin of man had fallen by the wayside.^[29] He argued that no lower animals could be identified as ancestors of man; nor did he think that science would ever be in a position to answer the question of man's animal origin. Four years later Menzbir published an article analyzing and refuting Virchow's argumentation point by point, mainly by relying on a string of authorities in evolutionary biology. Menzbir considered the animal origin of man a foregone conclusion; his major aim was to defend the power and resourcefulness of Darwinian theory and to uphold the supremacy of "scientific materialism." In the process, however, he gave Russian readers an opportunity

to learn about the basic issues that came in the wake of Darwin's suggestions on the ancestry of man.

P. P. Sushkin, a leading ecological evolutionist, noted in 1916 that in his lectures and published studies Menzbir relied on Darwinian models and analytical designs to give his own ideas inner consistency and overall unity.^[30] Although Darwin's ideas, in Menzbir's view, were not unchallengeable dogmas that discouraged criticism, they were impervious to sweeping criticism and flippant negation. Held together by firm principles, they needed only additional supporting facts, more precision, and wider vistas of research. Only the theory of sexual selection required a more radical reconstitution.^[31] Menzbir relied on the Origin of Species not only for help in general biological theory but for empirical information as well. To students in his zoology classes he presented Darwin both as the creator of a grand theory of evolution and as a true master of the inductive method. Darwin, he said, wanted his followers to treat the theory of evolution as an open system of ideas, inviting criticism and obeying the rules of the inductive method. Menzbir wrote:

Darwin's legacy stresses not a blind allegiance to his authority but a reliance on the inductive method of studying nature, discovering its laws, and unraveling its secrets. In none of his volumes do we encounter passages written in a dogmatic tone. Moderation and modesty give weight and credence to the proofs he uses in support of his theses.^[32]

Darwin's close adherence to the rules of the inductive method evoked most favorable—and very frequent—comments in Russia, among opponents no less than among followers. Particularly appealing was Darwin's abundantly displayed willingness to point out his own conclusions that required additional empirical testing and support. In The Variation of Animals and Plants Under Domestication Darwin made concrete suggestions on how to proceed in empirical testing of natural selection:

This hypothesis may be tested—and this seems to me the only fair and legitimate manner of considering the whole question—by trying whether it explains several large and independent classes of facts; such as the geological succession of organic beings, their distribution in past and present time, and their mutual affinities and homologies. If the principle of natural selection does explain these and other large bodies of facts, it ought to be received.^[33]

While praising the power and rich perspectives of Darwin's inductionism, Menzbir was only too ready to point out and to criticize the speculative constructions built into the theories of some scholars who considered themselves true Darwinists. Ernst Haeckel, as Menzbir saw

him, tried to dress Darwinian ideas in the abstractions of "the recently expired Naturphilosophie ."^[34] Right or wrong, Menzbir was convinced that individual German biologists were deeply steeped in the metaphysical habits of the masters of Naturphilosophie, even though this orientation had ceased to exist as an organized movement. Haeckel copied the logical forms, not the ontological foundations, of Naturphilosophie . The complete system of Haeckel's phylogenetic propositions built into the gastraea theory showed a full disregard of accumulated empirical evidence. Haeckel made no reference to the geographical distribution of plants and animals, and he had little respect for paleontology. He spent more time in creating nature than in studying it.^[35] As a systematizer of morphological knowledge, however, he made contributions of lasting value. In general, he was guilty, according to Menzbir, of not following Darwin's advice that the future triumph of the idea of evolution would come from the cooperative work of many branches of biology.

Contemporary developments in biology attracted Menzbir's attention only insofar as they referred to the key positions of Darwin's theory. In Theodor Eimer's theory of orthogenesis—built on the idea of organic evolution as a process moving in a definite direction and clearly affiliated with Lamarckian thought—he saw an unwelcome and dangerous invitation to teleological interference. In elaborating his orthogenetic views, Eimer refused to recognize random variation as a source of organic evolution. By rejecting the random occurrences of variation, he eliminated the need for natural selection. Nor did Menzbir favor Petr Kropotkin's theory of mutual aid, which categorically rejected Darwin's theory of the struggle for existence and was closely tied to Lamarck's idea of the direct influence of the environment on the evolutionary process.^[36] Menzbir was not impressed with the "successful" efforts of Kammerer, Standfuss, and E. Fischer to present the direct influence of the environment as a leading factor of evolution. Laboratory conditions, he said, accelerate the evolutionary process and make it unrepresentative of the work of nature. He was willing to accept the direct influence of the environment only in cases where it did not interfere with the work of natural selection.

In 1891 the popular journal Russian Thought invited Menzbir to contribute an article on "the present state of biology." Responding to the invitation, he wrote that all contemporary biologists were clearly divided into evolutionists (Darwinists) and antievolutionists (anti-Darwinists), that each group had made its position clear and irrevo-

cable, and that the differences between the two groups were irreconcilable, which made the ongoing strife a totally useless exercise. At this time Menzbir was firm in his belief that the anti-Darwinists were "soundly defeated." He saw the triumph of Darwinism not only in its answering specific questions related to organic transformation but also in its giving biology a general method.^[37] The task of modern biology was not to question the validity of Darwinian principles but to carry them to previously unexplored domains of nature. Arguing from a Newtonian position, Menzbir stated that to demand new proofs for Darwin's theory was "as unnecessary, and as harmful, as to enter into a polemic with Laplace."^[38] At this time, it should be noted, Laplace's views on the absolute and universal validity of causal explanations stood for the quintessence of Newtonian science.

In 1893 Menzbir no longer clung to the view of a sharp and irreconcilable split in biology between Darwinists and anti-Darwinists. Now he recognized the clear existence of an intermediate group of biologists who were neither anti-Darwinists nor orthodox Darwinists. This group recognized the generality of the Darwinian struggle for existence, but it also advanced an anti-Darwinian theory of heredity that placed exclusive emphasis on internal causation. Menzbir took the trouble to explain the details of Weismann's neo-Darwinian theory for the readers of Russian Thought . While welcoming Weismann's strong support for Darwinian natural selection, he argued that his interpretation of the mechanism of heredity required extensive refashioning and refinement. Weismann's theory of heredity, as Menzbir viewed it, suffered from conceptual overelaboration that made it far removed from both the experimental and natural-historical base of biology. In Weismann's "biophores," "determinants," and "ids," he saw unreal categories created by philosophical playfulness detached from the empirical underpinnings of modern science.^[39]

Despite these reservations, Menzbir did not hesitate to voice a favorable opinion about the potential usefulness of Weismann's theory of heredity. Weismann, he wrote, must be given credit for helping create a tradition in Russia that encouraged efforts to build a theoretical bridge between Darwin's legacy and experimental biology, particularly the branch concerned with heredity and variation.^[40] Although it was a product of a particular tradition in German philosophy rather than of solid empirical research, Weismann's theory was destined to serve for a long time as a source of fertile ideas.^[41]

Hugo de Vries's mutation theory, which viewed saltation rather than

"slight modification" as the real source of variation in the forms of life, acquired widespread reputation as a major assault on Darwin's theory. At first Menzbir looked at the new theory with a great deal of suspicion. He was unwilling to attach more importance to "sudden leaps" than to "slight modifications" in morphological features. Nor could he see how the extremely rare saltatory digressions from the norm of heredity could explain the universality and unceasing movement of evolution. He was not even sure whether de Vries's "mutation" and Korzhinskii's "heterogenesis" were one and the same thing, as they were generally assumed to be. The struggle for existence, he said, played an important role in de Vries's theory but did not figure at all in Korzhinskii's thinking.^[42] His first reaction was to count de Vries among the anti-Darwinists, whose ranks made significant gains at the turn of the century. He softened his criticism as soon as he learned that de Vries's allegiance to the idea of evolution, and to Darwin's natural selection, was not in doubt. In his judgment:

It is not generally known that de Vries is an evolutionist; if he were not an evolutionist he would not have spent long years in search of an answer to the question of the origin of species. Never questioning the transformability of species, he worked carefully and impartially on experiments aimed at decoding "the secret of secrets," as the origin of species was previously termed.^[43]

After having completed a critical survey of de Vries's mutation theory, Menzbir drew a conclusion that characterized his rather uncertain attitude toward the challenges of the new experimental biology to the Darwinian orthodoxy:

De Vries's theory, still requiring elaboration and still unsettled in its foundations, cannot replace Darwin's theory, which is well balanced and general, and can answer an infinite series of questions. Nor can it cause a crisis in the development of Darwinism, which has brought together all branches of biology. But my last word about de Vries's research shall not be negative. There, where so much work has been done to answer the most important biological questions, even if that work has contributed only a few grains of truth to science, there can be no negative judgment. Even if we cannot agree with the conclusions of the creator of the mutation theory, we sincerely hope that he will continue his experimental work. Without doubt, this work will produce many new ideas, which may or may not sustain the mutation theory.^[44]

Menzbir was less kind to the Russian botanist S. I. Korzhinskii, whose theory of heterogenesis, made public in 1899, attracted much attention in the West. Like de Vries, Korzhinskii recognized saltatory changes, not caused by external influences, as the primary source of

morphological variation in plants and animals. In one respect, however, the two scientists were far apart: while de Vries recognized natural selection and the struggle for existence as factors of evolution and was full of praise for Darwin's contributions to the triumph of the evolutionary view in biology, Korzhinskii had nothing kind to say about Darwin's conclusions and was ready to reject evolution as a useful biological notion. Menzbir lamented Korzhinskii's premature death, which prevented him from completing the work on his new theory. He claimed that Korzhinskii ignored the actual processes linking heterogenetic change to the emergence of new species.^[45] Menzbir reminded his readers that Darwin was fully aware of saltatory changes and their role in the origin of new species. He was convinced, however, that their exceedingly rare occurrence makes it impossible to treat them as a major factor in the general evolutionary process.

Menzbir was untypically slow in commenting on the rediscovery of Mendelian laws of heredity in 1900. The third edition of his popular university textbook in zoology and comparative anatomy, published in 1906, surveyed the basic principles of the mutation theory, but it fully ignored Mendel and current elaborations of Mendelian genetics. He waited more than twenty years after the rediscovery of Mendel's laws of heredity to comment on the relations of genetics to Darwinism. At that time he acknowledged Mendel's contribution to "the field of hybridization" and to the study of the "mechanism of heredity," but he was sure to add that all this did not explain "the evolution of the organic world" and that Mendel did not make such a claim in the first place.^[46]

In Menzbir's view the future of Darwinism, and of science in general, was in the expansion and refinement of the mechanistic view of the universe. He made little effort to examine the growing attack on Newtonianism by the swelling ranks of contemporary scientists and philosophers. He wrote in 1901 in the widely circulated Russian Thought :

The nineteenth century was dominated by the idea that the phenomena of life are open to mechanical explanation, a conviction that met no opposition. The superiority and the power of mechanical explanation are built on the obvious fact that this mode of scientific thinking offers simple and comprehensive interpretations of phenomena, uses the established methods of the exact sciences, and penetrates the depths of the most complex and mysterious phenomena of life. The mechanical approach offers a powerful analytical tool that can handle even the most complex living phenomena and their minutely segmented components. . . . The so-called philosophical school continues to claim that, despite their brilliant discoveries, the scientists continue to be unable to explain force, matter, and life. This is not true;

every scientist has an excellent understanding of life. Regardless of how we view organisms, we know that a plant lives as long as chlorophyll gives it energy by dissolving carbon dioxide and as long as it produces starch. We know that an animal lives as long as its nervous system receives impressions from the outside world and reacts to them. We also know that both plants and animals live only so long as they exist in both space and time. Inasmuch as our study of vital phenomena depends on the methods employed in the study of all other forms of motion, it produces the same results as long as we do not separate the notion of the organic from the notion of the inorganic. We know the difference between these two categories of phenomena. But we also know that all forms of motion in nature—from molecular motion to the motion of celestial bodies—give us an idea of uniformity and harmony superimposed upon the innate diversity of natural phenomena. The nineteenth century built a bridge between inorganic substance and protein compounds, between protein as a cosmic body and protein as a self-destroying body, and between plants and animals, the latter endowed with strikingly complex behavioral mechanisms. It made all phenomena parts of an indissoluble chain. While coming quietly to a close, it presented all those who showed interest in science with a picture of the grand unity of nature, revealed in the gradual development of the universe.^[47]

Menzbir was not very comfortable in discussing philosophical issues. He thought that idealism and materialism, each as a distinct philosophical strategy, had contributed to the accelerated progress of modern science. Idealism helped elaborate and refine the deductive method and the growing role of mathematics in the growth of scientific knowledge.^[48] Materialism made a major contribution to the creation of a unified picture of the universe: it made "matter and motion" the common denominators of inorganic and organic worlds. Materialism had shown that "nature is one"—that every natural phenomenon is part of a causal link, and that there is no predetermined purposiveness in nature, even though there is harmony. While making tactical concessions to the idealistic strain in science, Menzbir appeared to have been leaning toward materialism—toward the idea of the sovereignty of "matter-in-motion." In another paper he stated explicitly that the triumph of "mechanical explanation" in biology was one of the greatest achievements of the nineteenth century.^[49]

Menzbir admitted that Darwin's theory had not yet achieved full victory. He believed, however, that Darwinism would not only survive all the challenges that came from experimental biology, various branches of neo-Lamarckism, and organismic metaphysics, but would acquire new strength and authority. The new biological theories, he said, can survive and become parts of modern scientific thinking only insofar as

they contribute new information and modes of inquiry to the grand edifice of Darwinian science. The new theories enriched Darwinism, and they also benefited from it. "It is difficult for us to imagine how Darwin would have reacted to the data put forth by his enemies. But we do know that Darwin was aware of the ideas that went into the making of de Vries's mutation theory and Mendel's law of heredity."^[50]

Despite accumulated challenges to its principles, Darwinism, as Menzbir viewed it, represented one of the greatest intellectual challenges of modern time. It inspired all those who cherished the spirit of free inquiry and who showed no fear of transgressing the limits of thought imposed by tradition. "Darwinism became a horrifying specter for all those who were steeped in prejudice and egotism." Darwin's theory, Menzbir argued, was too viable and too timely to be crushed by its enemies. The bitter attacks on it during the 1880s—the Danilevskii-Strakhov era—succeeded, in his opinion, neither in beclouding its rising star nor in undermining its scientific principles; they merely showed the deep pessimism of a society in crisis—a society devastated by intellectual "darkness," "moral crisis," and "loss of faith in itself." Menzbir made it clear that "pessimism" and "moral crisis" had taken deep roots in a large part of the civilized world. In his view, the bitter attacks on Darwin's theory were the purest symptoms of the intellectual and ethical disorientation of modern society.^[51]

Darwin, as Menzbir saw him, wrought a revolution in biology and radically transformed the modern world outlook. His works are rich in theoretical thought and research perspectives and are well stocked with precious empirical data and cogent insights. Menzbir was determined to present Darwin as a model scientist—a personification of the highest standards of contemporary scientific methodology. Guided by "the spirit of free inquiry," Darwin tolerated only the ideas open to challenge. He freed science from metaphysical and theological doctrines and modes of thinking, as well as from intellectual subservience to authority of any kind. By purifying the inductive method, he contributed to the modern emphasis on experimental studies and to a methodological recognition of the unity of inorganic and organic nature. Menzbir joined the commentators on the general development of modern scientific ideas who called Darwin "the Newton of biology."^[52]

With Darwinism uppermost in his mind, Menzbir worked on many fronts of biological scholarship. He carried on empirical and synthetic research in ornithology and wrote special essays showing the effectiveness of Darwin's theory as a research tool. In a series of biographical

sketches of the pioneers of modern evolutionary biology he illumined the key ramifications of Darwin's theory and the most potent challenges germinated by more recent developments in evolutionary thought. Not avoiding a confrontation with the philosophical aspects of Darwinism, Menzbir worked with remarkable consistency on clarifying and strengthening the Newtonian base of evolutionary biology. He participated in public debates on the issues of evolution and served as a busy functionary of the Moscow Society of Naturalists. The writer of a successful university textbook on zoology and comparative anatomy, he also translated several biological-evolutionary classics from the English language, including Alfred Russel Wallace's Darwinism and Natural Selection . He was partly responsible for one of the better Russian translations of the Origin of Species .

In 1900 Menzbir published a series of essays under the general title "The Leading Representatives of Darwinism." Individual essays presented the evolutionary views of Wallace, George Romanes, Haeckel, and Weismann. A few years earlier he had published a similar essay on Thomas Huxley. His aim was clearly to show the flow of evolutionary ideas from various disciplinary sources to a central pool of knowledge and to point out both the commendable contributions to and the lamentable digressions from the basic principles of Darwin's theory. The study of "digressions" produced a significant by-product: it led Menzbir to point out the domains of evolutionary thought, such as the theory of heredity, which needed help from the non-Darwinian effort in biological research. In the work of Haeckel and Weismann, Menzbir detected a strong influence of the cognitive habits and metaphysical propensities of Naturphilosophie, which separated the idea of evolution from the reality of empirical data. He did not approve of Wallace's claim that mental differences between man and animal are differences of kind rather than of degree;^[53] and he thought that Romanes's "theory of physiological selection," intended to replace Darwin's theory of natural selection, consisted of incongruous parts that prevented it from acquiring empirical support.^[54] Despite the shortcomings of certain aspects of their theories, Menzbir admitted that these scholars provided the main wheels for the triumph of Darwinian ideas and for carrying the theory of natural selection to new areas for research. Haeckel's empirical work represented the high point in the development of evolutionary morphology; Wallace was the most consistent and most thorough defender of Darwin's general theory; Weismann showed the path for the experimental study of heredity; and Romanes carried Darwin's theory to the vast area of "mental evolution."

A. N. Severtsov:
Morphology and Evolution

Severtsov belonged to the same group of evolutionary biologists as Timiriazev and Menzbir: he was a thorough Darwinist, not interested in accommodating himself to anti-Darwinism, neo-Darwinism, or quasi-Darwinian developments in evolutionary thought. Unlike Timiriazev and Menzbir, he dedicated his life much more to a search for new parameters and logical elaborations of Darwin's theory than to a popularization and defense of Darwinism. He firmly accepted Darwin's views on the struggle for existence, natural selection, heredity, and variation as the basic factors of the evolutionary process. His research interests, however, did not embrace these problems, the key categories of Darwinian thought. The causes of evolution did not attract his attention: he concentrated on the paths and modes of evolution. In this enterprise his task was not to create a new general theory of organic evolution but to give Darwin's theory more depth and broader compass. He was both an astute defender of Darwin's biological legacy and one of the more original and profound contributors to the elaboration of Darwinian evolution.^[55]

As a scientist, Severtsov displayed two general characteristics. First, in his work on the general theory of evolution he depended heavily on the empirical studies conducted by himself and his numerous disciples. His studies radiate an air of fresh exploration both on empirical and on theoretical levels. Second, his approach is interdisciplinary. Although he concentrated on elaborating and codifying the high theory of evolutionary morphology, he drew extensive help from comparative anatomy, embryology, and paleontology. If he ignored physiology and its contributions to the general theory of evolution, it is not because he did not appreciate its strength but because it was outside his competence. He also thought that modern physiology developed in a direction that did not particularly encourage a direct concern with the essential problems of evolutionary biology.

Severtsov's father—Nikolai Alekseevich Severtsov—was a wellknown biologist, combining a strong interest in natural history with biological theory. He was particularly noted for his faunistic and floristic surveys of the Tien-Shan Mountains and the Pamirs. In his widely read Reminiscences, L. F. Panteleev reported that in 1861 Severtsov gave a series of public lectures on the Origin of Species .^[56] During the 1870s his studies showed clearly a firm affiliation with Darwinism. "Darwin's theory," he wrote at this time, "is a convenient and solid philosophical umbrella or a common denominator for all the observable gen-

eral phenomena of organic nature."^[57] In 1876 he visited Darwin in Down. In a special analysis of the emergence of new species among the shrikes of the central Tien-Shan, he placed a strong emphasis on natural selection and felt that he had helped confirm Darwin's theory.^[58] His contribution to Darwinism, he noted, came not from books but from direct study of Central Asian nature. The Vertical and Horizontal Distribution of Turkestan Animals, the first systematic and comprehensive survey of the vertebrates of the region, is rich in analysis inspired by Darwin's theory.^[59] His description of the fifteen newly discovered species of mammals and forty-nine species of birds included rich data on the effects of geographical distribution on evolutionary change. Severtsov showed a particularly keen interest in ecology and systematics as evolutionary disciplines. In his strong emphasis on the direct role of environment in the transformation of species he was a follower of Lamarck.

The family atmosphere helped Aleksei Severtsov acquire a profound appreciation of Darwin's contributions to evolutionary biology and a keen interest in the type of scientific research that combined empirical inquiry with a search for regularities in the work of nature. In 1890 he graduated from Moscow University at the time when this institution was firmly established as the national center for Darwinian studies, thanks primarily to the work of Timiriazev and Menzbir. Four years later he read a paper on the primary and secondary metamerism of the head of vertebrates, at the Ninth Congress of Russian Naturalists, held in Moscow. In 1896—97 he was in western Europe working in laboratories, conducting empirical research, writing papers on sharks and electrical skates, participating in seminars on current developments in cytology and histology, and observing the Western scientific community at work.^[60] He benefited most from his association with Kupffer and Boehm at Munich University and with Anton Dohrn at the Naples Marine Zoological Station.

After a long teaching engagement at Dorpat and Kiev universities, Severtsov returned to his alma mater in 1911 as professor of comparative anatomy. His transfer coincided with Timiriazev's and Menzbir's resignation from Moscow University in protest against the efforts of the Ministry of Public Education to suppress the student movement and to curtail academic autonomy. A professor at Moscow University until 1930, he offered courses in general zoology, vertebrate zoology, comparative anatomy, and the theory of evolution.^[61] Clearly demarcated and individualized, all courses were united by an overarching interest in the theoretical aspect of biological evolution. In 1920 he was elected to

full membership in the Russian Academy of Sciences in Petrograd. Contrary to the time-honored custom, he was allowed to remain in Moscow and to continue his teaching activity at Moscow University.^[62]

Severtsov's works published during the Soviet period, particularly his Morphological Laws of Evolution, gained him an international reputation as a leading scholar in evolutionary morphology.^[63] These works offered a grand synthesis and elaboration of the theoretical ideas presented in three essays he had published before the October Revolution: "Evolution and Embryology" (1910), Studies in the Theory of Evolution (1912), and "Modern Problems of Evolutionary Theory" (1914). These early works represented an impressive effort to make morphology the core system of theoretical categories in evolutionary biology. Unlike Timiriazev, he added new ramifications to Darwinian thought while, at the same time, living in peace with rapid developments that opened new and challenging vistas in the experimental study of evolution, particularly in the domain of heredity and variation.

Severtsov's empirical work showed a rich diversity of topics closely related to the theory of evolution and a high degree of technical competence. During the 1890s he concentrated on the study of the metamerism of the vertebrate head, that is, on the emergence and evolution of the head among the vertebrates as the center of sense organs, brain, and skull. During the first decade of the twentieth century he advanced a new theory of the origin of the pentadactylous extremity in the multiradial fin of primordial fishlike forms. Subsequently he worked on the origin and evolution of lower vertebrates and drew a genealogical tree of these animals by adding reconstructed missing links to presently existing and paleontologically documented species. The purpose of his empirical research was to test specific theoretical ideas or to illumine general issues that invited controversial interpretations.

General theoretical concerns, all related to organic evolution, occupied a central position in Severtsov's involvement in science. The biological tradition, he said, had advanced three major phylogenetic approaches to evolution: paleontological, comparative-anatomic, and compararive-embryological. Readily acknowledging the strengths and weaknesses of all these approaches, his research experience convinced him that the time had come to accord morphology a central position among the evolutionary disciplines in biology. Morphology, he thought, should not only occupy the strategic position among the biological sciences but should also undertake the task of producing a general synthesis of evolutionary thought. He claimed that the time had come for

morphology to go beyond its traditional concern with genealogical trees—and with empirical generalizations—and to become engaged in a search for "the morphological laws of evolution."^[64] The contemporary study of phylogeny, he felt, formed only a preliminary phase in the general search for morphological laws of evolution.

Severtsov worked most successfully in two areas of evolutionary theory: the theory of phylembryogenesis, an elaborate approach to the relationship of phylogeny to ontogeny as a mechanism of evolution, and the general theory of morphology, concerned with universal regularities or laws of organic evolution.^[65] Since in both areas evolution figured as the main object of inquiry, he preferred to label his approach as a historical orientation in biology. In both the theory of phylembryogenesis and the general theory of evolutionary morphology he made an effort to produce a new integration of generalized knowledge.

The theory of phylembryogenesis is "the theory of evolution seen through changes in the course of embryonic development." It is a search for answers to such fundamental biological questions as the correlation between "individual" and "historical" development of characters—between ontogeny and phylogeny. In a way, this theory is an elaboration of Darwin's effort to transform the "law of parallelism," referring to similar characters in different lineages, into the "law of correlation," referring to similar characters in ontogenetic and phylogenetic developments. The theory of phylembryogenesis is in essence a systematic coordination of ontogenetic and phylogenetic developments of "morphological" characteristics. It has laid the groundwork for evolutionary morphology.^[66] Severtsov contended that "ontogeny is a function of phylogeny," that is, that without an understanding of phylogeny we cannot understand the laws of individual development—strictly speaking, the laws of life.^[67] But he also contended that changes in ontogeny are the real source of changes in phylogeny; ontogeny not only repeats phylogeny but also makes it a historical process, subject to constant change.

The theory of phylembryogenesis created a wide base for a systematic inquiry into a complex set of challenging problems. The work on four such problems had proven particularly attractive: regularities in the evolutionary aspect of ontogeny; bonds between the ontogeny of animals and the conditions of their existence, including the adaptation of individual organs to functional changes; comparative data on the ontogenetic development of closely related species and genera; and ties between theoretical inquiry and practical problems, particularly those related to animal breeding.^[68] Russian biologists were particularly attracted to the general theory and ecological dynamics of phylogeneti-

cally significant ontogeny. A new discipline—ecological embryology—grew in the tradition of Severtsov's biological thought.

Severtsov's extensive empirical research, particularly among lower vertebrates, led him to recognize three basic modes of phylembryogenetic changes: anaboly (extension of the last stages of morphogenesis), deviation (changes during the middle stages), and archallaxis (changes during the initial stages). Severtsov was particularly anxious to point out the relationships of individual modes of phylembryogenesis to the tempo and general character of evolution. Anaboly, as he saw it, refers to changes that are exceedingly slow but that lead to highly diversified phylogenetic alterations. Archallaxis, by contrast, depicts discontinuous leaps and relatively fast changes. Deviation occupies a position between anaboly and archallaxis. The notion of three modes of evolution led Severtsov to revise Haeckel's biogenetic law. He accepted the idea of the ontogenetic recapitulation of phylogeny, but he linked it only to anaboly.

In general, Severtsov's theory of phylembryogenesis is an elaboration of two general ideas. First, phylogenetically significant change can take place in every phase of ontogenetic development.^[69] Or, as Bernard Rensch has stated in reference to the work of the Severtsov school: "The results obtained so far indicate that phylogenetic alterations may appear first in very different stages of the ontogenetic development."^[70] Second, during the growth of an organism, phylogenetic alteration takes on different forms and intensities: the earlier the stage of ontogenetic development, the broader the phylogenetically significant changes. Early stages produce alteration in the characteristics of families, classes, or other larger taxonomic groups and affect entire complexes of organs. Phylembryogenesis, in Severtsov's view, is the primary fountain of information on the evolution of the forms of life.

Haeckel studied the relationship of ontogeny to phylogeny only insofar as it helped him in his lifelong project to construct a universal genealogical tree of the animal world. For this reason he was interested in ontogeny as a true recapitulation of phylogeny. Severtsov had an additional interest: he treated the study of this relationship as a preliminary step in a broader effort to formulate the general morphological laws of evolution.^[71] He criticized Haeckel for his inclination to limit evolutionary biology to the study of phylogeny, but he also rejected the neovitalist claim—most explicitly stated in Rádl's History of Biological Theory —that "Darwinian morphology" could never become a historical discipline, for the simple reason that it had no access to historically significant data.

Severtsov's second major activity concentrated on the formulation

and elaboration of evolutionary morphology as a system of integrated theoretical principles. He wrote in 1912:

In recent times, there has emerged a new orientation in the study of the evolutionary process. Independently of each other, paleontologists (paleobiologists), comparative anatomists, and embryologists have adopted this orientation. Previously, all these specialists limited their study exclusively to the evolution of individual groups of animals, and to construction of phylogenetic trees, that is, to preparation of as complete a [genealogical] record of the animal kingdom as possible. At the present time biology has advanced so much that it has become possible to undertake another task that had eluded old zoologists—the study of phylogenetic regularities in the evolutionary process.^[72]

Early Darwinists laid the foundations for a phylogenetic classification of larger taxa, established the phylogeny of a series of organs from head and brain to gill and fin, and unveiled some regularities in the evolutionary process, typified by Haeckel's biogenetic law.^[73] They had spent much time in gathering empirical material related to evolution; the time had now come to concentrate on the search for morphological laws, the quintessential expression of the regularities of organic evolution. Severtsov observed, however, that notable efforts in that direction had already been made, as was shown by such general principles as Osborn's "adaptive radiation," Anton Dohrn's "change of function," N. Kleinenberg's "substitution of organs," L. Plate's "extension and intensification of functions," and D. M. Fedotov's "physiological substitution."^[74] These principles, all pointing in the right direction, required further elaboration, particularly inasmuch as they were interrelated. Above everything else, morphologists were required to search for previously undetected regularities in the evolutionary process.^[75] According to Ernst Mayr, Severtsov contributed to an explanation of the "intensification of function" as a distinct regularity in morphological evolution. Mayr referred specifically to Severtsov's explanation of the conversion of the five-toed foot of primitive ungulates into a two-toed or one-toed foot.^[76]

Severtsov worked on two fronts: he looked for morphological regularities as revealed by direct empirical research, and on a purely theoretical level he endeavored to formulate and codify the morphological laws of evolution. On the empirical level, as a matter of personal taste and predilection, he worked mainly on those embryonic changes that are preserved in adult organisms as adaptation to the environment.^[77] In his empirical search for general modes of morphogenesis he relied heavily on ecological material. Much of his general theoretical work concen-

trated on giving morphology a firmly postulated and comprehensive evolutionary orientation.^[78]

In elaborating the general principles of evolutionary morphology, Severtsov was noted particularly for his effort to make the notion of progress an integral pan of evolutionary studies.^[79] He drew a line between morphophysiological progress in the organization of animals and biological progress in the survival potential of individual species. The first refers to the increasing and decreasing morphological complexity of living forms; the second is based on three criteria: increase in the vitality and rate of growth of a species; the expanding size of the area occupied by a species; and the splitting up of a species into subordinate taxonomic groups, the so-called adaptive radiation.

In his later work Severtsov developed a scheme of four modes of "morphological progress." Aromorphosis, the first mode, designates "the most general adaptive change in the organization and functions of animals, which normally increases the vital energy of animals and the diversity of their forms (differentiation)." This mode of change is important biologically inasmuch as it marks "a useful adaptation of animals to changes in the environment and inasmuch as it produces stable characteristics."^[80] In brief, aromorphosis stands for the evolutionary process as postulated by Darwin's theory. I. I. Shmal'gauzen, the most authoritative interpreter of Severtsov's scientific legacy, viewed aromorphosis as "a more substantial step in the process of transformation, signifying the rise of an organization to a higher level on the [evolutionary scale]."^[81] B. S. Matveev, another disciple, did not hesitate to identify aromorphosis as saltatory change.^[82] Idioadaptation, the second mode, usually follows aromorphosis. It denotes adaptation to specific conditions of life, which, however, does not add to the complexity of organization.^[83] This mode of evolution explains the mosaic character of present-day flora, made up of forms that, by their morphological character, belong to various geological eras. Cenogenesis, the third mode, stands for embryonic adaptations not reflected in the structure of grown organisms.^[84] These adaptations are progressive inasmuch as they help increase the proportion of animals reaching the age of maturity. Regression, the fourth mode, denotes morphological simplification as an adaptation to specific conditions of existence. It is best illustrated by animals that change from a roaming to a stationary way of life or from active to parasitic feeding.^[85] "The process of partial or general regression," according to Severtsov, "should in no case be identified as a phenomenon of degeneration. In all cases we have analyzed, the process of regression is useful to

a group of animals and enhances their adaptability to the given conditions of existence: morphological regress becomes a condition of biological progress." The adaptability of organisms may be strengthened by the increased efficiency of existing organs; but it may also be strengthened by the disappearance or atrophy of individual organs. He recognized two kinds of regressive changes in organs: changes in which the functions of eliminated or atrophied organs are not taken over by other organs, and changes in which they are transferred to other organs. Severtsov contended that no mode of adaptive evolution occupies a dominant position—that "animals can exist and flourish for an unlimited time regardless of the evolutionary path they have followed."^[86]

In essence, evolution, as Severtsov interpreted it, is a result of the adaptation of organisms to the environment. Adaptive change is primary or correlative. Primary change is the main course of evolution; correlative change is a by-product of primary change and is totally dependent on it for survival—if primary change is erased, correlative change becomes atrophied. Since it is not hereditary, correlative change may or may not recur with regularity.^[87] While recognizing the Lamarckian use and disuse of organs as an evolutionary factor, Severtsov gave it only a correlative significance. He rejected the Lamarckian use and disuse of organs as a source of heritable characteristics.^[88]

In paying homage to the Russian scientists who contributed to the advancement of the general theory of organic evolution, Severtsov selected P. P. Sushkin for special praise. An ecologically oriented evolutionary biologist, Sushkin studied the role of major climatic and geomorphological changes in the evolution of vertebrates.^[89] He produced suggestive ideas on the combined effects of these changes in giving a unique direction to the evolution of mammals. Severtsov thought that Sushkin's work opened wide possibilities for a systematic and comprehensive study of the evolutionary role of environmental factors. He felt much closer to the environmentalism of the Lamarckian tradition than to the Mendelian legacy, which regarded environment as an evolutionary factor of secondary importance.

The scientific study of the evolution of animals, as Severtsov saw it, must take into account two separate factors: the organization—the degree and the complexity of the structure—of animals at the time a change takes place in the habitat, and the general direction of change in the habitat. The first factor determines the change in a given organism, for it is well known that a specific change in the environment may be differently reflected in various animal and plant forms. The second fac-

tor determines whether the particular change in a given organism will lead to progress or regress, divergence or convergence. "These are regularities," he said, "of very general character that worked in the past, that work at the present time, and that most probably will work in the future."^[90]

Severtsov accepted the struggle for existence as an empirically verified fact. He also accepted the idea that the influence of the environment on the process of evolution is "indirect," rather than "direct," as Buffon and Lamarck had emphasized.^[91] He dealt, however, much more with the morphological aspects of variation than with the prime causes of transformation processes.^[92] Despite powerful challenges from genetics, Severtsov stuck steadfastly to the Darwinian view of environment as a primary—even though an indirect—factor shaping and directing the process of evolution.

The question of evolution as a reversible process did not escape Severtsov's attention. L. Dollo, the well-known Belgian paleontologist, suggested that evolution is an irreversible process, by which he meant specifically that an organ cannot repeat evolutionary phases it had left behind in its long historical journey. Some biologists generalized this suggestion into a universal law of the irreversibility of evolution. Severtsov thought that Dollo's suggestion could be accepted only with reservations. When we state, for example, that a fully atrophied organ cannot be restored to a normal state, we are making an empirical statement that we do not know of any case of a restoration of such organs. In some cases, however, the reversibility of the evolutionary process can be readily documented. In the evolution of a part of the skeleton of some species of deepwater fish, to give one example, flexible cartilage was replaced by inflexible bone which, in turn, was replaced by flexible cartilage. Severtsov was ready to admit that the cases of the reversibility of evolution were exceedingly rare.^[93]

Severtsov made an explicit statement on the nature and the strength of Darwin's theory and, by implication, on the reason for his belief that the basic postulates of this theory were unchallengeable. He wrote in his classic Studies in the Theory of Evolution (1912):

For our purposes, it suffices to note the following features of Darwinian evolutionism that separate it from all preceding evolutionary constructions and make it a solid basis for further research in the theory of evolution. According to Darwin, the ultimate cause of phylogenetic change in the organization of animals is always the change in the conditions of existence, that is, in the surrounding environment, taken in a broad meaning of the term. For

the most part, change in the conditions of existence exercises an indirect influence on the organism, that is, it determines the direction of the accumulation of individual variations acquired by natural selection. Without a change in conditions, there can be no change in species. . . . From a theoretical point of view, it is equally important that Darwin does not rely on an unverifiable and unprovable internal evolutionary principle, not related to changes in the environment. In other words, Darwin's theory deals with facts open to direct verification by experiment and observation. In his opinion, phylogenetic changes, as products of natural selection, always appear as useful adaptations of organisms to their environment. They are purposive alterations in the structure and functioning of a given animal. It is possible that Darwin was in full agreement with the principle of purposiveness in the living world, but, unlike Karl von Baer, he treated it, not as a basic—and unfathomable—quality of organisms, but as a problem open to examination. His entire theory serves as a brilliant explanation of the phenomenon of organic purposiveness, which at first sight appears so mysterious.^[94]

In von Baer's view, purposiveness antedates organic evolution—evolution is a creation of predetermined purposiveness. Darwin, by contrast, viewed purposiveness as a creation of evolution; the higher the place of a species on the scale of evolution, the more complex the inner mechanics of its purposive action. In Darwin's view, as Severtsov interpreted it, purposiveness is an empirical phenomenon subject to natural causation; it is an evolutionary variable, not a "constant" of organic life.^[95]

Despite his deliberate effort to avoid sociological involvement, philosophical construction, and popular elaboration, Severtsov reached a wide-ranging reading public. The magic of his influence was not only in the innovative character of his theory but also in the lucidity, appealing precision, and natural flow of his writing style. Particularly appealing was his attitude toward Darwinism as an open theory, inviting new research on substantive, methodological, and conceptual levels. His criticism of anti-Darwinian orientations was mild but not perfunctory. Unlike Timiriazev, he did not subject his "enemies" to unmitigated scolding.

Severtsov's close adherence to the uniformitarian roots of Darwin's thought prevented him from taking serious note of theories advocating multiple lines of evolution and of the emergence of new causal factors in the transformation of species, such as, for example, the accumulated effects of human intelligence. As an uncompromising critic of autogenesis, he could not help but look with suspicion at some of the most dynamic and promising branches of experimental biology. Suspicion,

however, did not prevent him from anticipating a convergence of Darwinism and the new genetics.^[96]

Severtsov is remembered for his effort to draw a clear line between Darwinism as a science and Darwinism as a world view, or as an ideology. Darwinism as science is a system of theoretical thought inviting challenge and open to change. Darwinism as a world view is a system of beliefs and sentiments that discourages any criticism of its basic premises and is intolerant of change in basic evolutionary theory. The representatives of resurgent vitalism, particularly strong in Germany but not without influential spokesmen in Russia, criticized the scientific foundations of Darwinism from the vantage point of a world view steeped in idealistic metaphysics. Hans Driesch, in his view, rejected Darwinism on ideological grounds, but his effort was unsuccessful on scientific grounds. Severtsov stated:

It is clear that the antagonism between neovitalism, on the one hand, and the general evolutionary theory and Darwinism, on the other hand, is based on historical and psychological arguments rather than on logic. Despite the scientific veneer and mathematical formulas of Driesch's theory, neovitalism is not a scientific theory but a philosophical world view shared by a group of modern biologists. Driesch is linked to the modern idealistic orientation in metaphysical thought to the same degree that the Naturphilosophie of Oken and Carus was linked to the philosophy of Fichte and Schelling.^[97]

Severtsov was careful to point out the basic differences between neovitalist and Darwinian interpretations of the work of purposiveness in the living world. To a typical neovitalist, purposiveness is an "internal teleological principle" that cannot be analyzed into component parts and into empirically ascertainable elements. It is inaccessible to scientific scrutiny. To Darwinists, as Severtsov represented them, purposiveness is a complex process that can be divided into functional components and is open to empirical ascertainment and scientific inquiry. Whereas to neovitalists purposiveness is a metaphysical category, totally inaccessible to science at the contemporary level of its methodological competence, to Darwinists it is an empirical category and a legitimate object of scientific study.

We know, wrote Severtsov, that every great scientific discovery shapes the world view of the given time. Galileo and Newton helped create the world view of their time, and more recently Darwin had played a similar role. The world views of Galileo and Newton had gone out of style, and it is possible that the same fate awaits Darwin. Even if this happens,

it will not reduce the value of Darwin's contributions to science: Darwinism will continue to serve as a "working theory" for zoologists and botanists insofar as they concern themselves with the relations between the organism and the environment. "Although we attach great value to Darwin's theory, we have no right to be dogmatic and to be satisfied with the achievements of Darwin and his immediate followers: scientific theories are strong inasmuch as they open possibilities for new discoveries and for asking new questions."^[98] Severtsov showed exemplary loyalty to the cardinal principles of Darwin's theory, but he never abandoned the idea that Darwinism needed much elaboration and refinement.

Compared with Timiriazev, Severtsov showed more subtlety and more precision in separating Darwinism as a world view from Darwinism as a turning point in modern science. He readily admitted that science and the world outlook are overlapping cognitive and sociological categories. The modern world outlook contains intellectual ingredients drawn from science; science, in turn, harbors residual beliefs drawn from the world outlook. He merely noted that, in validating relevant knowledge, science and ideology use different standards. A scientist depends on the rigor of logic, theoretical consistency, and empirical verification in accepting new knowledge and in integrating this knowledge into larger systems of secular wisdom. An ideologue, by contrast, validates knowledge by establishing its compatibility with preferred values and philosophical prejudgments. A scientist depends on the weight of "proofs"; an ideologue depends on the "harmony" between the facts of science and his scale of values.^[99] A vitalist in biology errs in judging scientific theory from the standpoint of idealistic metaphysics, a unique world outlook. Ernst Haeckel, on the other hand, was guided by the criteria of materialistic metaphysics when he translated Darwin's theory into a rigid monistic system. Severtsov was ready to recognize Haeckel's specific effort to make Darwin's theory the cornerstone of a scientific theory of organic evolution. He was not ready to recognize Haeckel's specific effort to make Darwin's theory the cornerstone of a closed philosophical system. He knew that Darwinism was caught in a double crisis: the crisis generated by new advances in science (particularly in genetics), and the crisis caused by ideological conflicts and uncertainties.

Timiriazev placed Darwinian study within a narrow framework: he endorsed all the cardinal principles that went into the making of Darwinian evolutionism, but he did very little to elaborate, refine, and ramify these principles. He was a doctrinaire Darwinist in a very strict

sense. Severtsov was different by virtue of his temperament, intellectual bent, and theoretical achievement. Like Timiriazev, he made no effort to disrupt the symmetry and logical harmony of the theoretical principles that gave Darwin's theory its distinctness and inner unity. Unlike Timiriazev, however, he carried Darwin's principles to previously unexplored, or little explored, domains of evolutionary biology, and he gave these principles a more precise meaning and authority. He had a livelier predilection for exploratory work in the realm of general theory and a clearer picture of the countless research vistas Darwin's work had bequeathed to future biologists.

In the process of giving morphology an evolutionary orientation, Severtsov gave the theory of evolution both new support and new research challenges, and in the end produced a very active school of biological thought. In one important respect, however, Severtsov did not keep pace with contemporary developments in biology: he did not go beyond general pronouncements about the promising perspectives of a closer cooperation of evolutionary morphology with experimental biology in the common search for a general theory of organic transformation. Mark Adams has given a judicious appraisal of the evolution of Severtsov's attitude toward genetics:

Severtsov's attitude toward genetics was less a product of his own reorientation toward experimentalism than a response to the changing orientation of geneticists toward evolutionary theory. He had bemoaned the antagonism of such geneticists as Bateson, Johannsen, and Filipchenko toward Darwinism, but came to applaud genetics when it began to disprove neo-Lamarckian views, confirm natural selection, and favor evolutionary theory as he knew it. However, genetics had still not really provided a theory of the causes of evolution in Severtsov's terms because genetics, and even population genetics, had still not made any progress toward explaining the major macro-evolutionary phenomena.^[100]

Severtsov was firmly convinced that the pioneers of genetics—as represented by Bateson and Johannsen—were at first much more interested in advancing a "static" approach to heredity than in joining evolutionary studies. Gradually, the leading geneticists accepted the idea of casting their experimental studies within evolutionary frameworks, thus opening the doors for fruitful cooperation with Darwinian scholars. The new biology widened the base for the study of organic transformation and for work on an integrated evolutionary theory.

In his attitude toward the new branches of experimental biology, Severtsov showed much uncertainty and considerable wavering. For ex-

ample, he recognized mutations as a key factor of organic evolution, but, at the same time, he reaffirmed his position as an unbending foe of autogenesis. It is most probable that he thought of mutations as environmentally induced leaps in the evolutionary process, subject to natural selection. Despite all the reticence and uncertainty, he deserved credit for alerting his students to the great achievements and promise of experimental biology. The time was fast approaching, he said at the end of his distinguished career, for the students of ecology, genetics, and developmental mechanics (W. Roux's Entwicklungsmechanik ) to join forces in the search for new perspectives in evolutionary thought.^[101] He wrote at this time: "We are fully justified in claiming that the vast and valuable material collected by geneticists and students of mutations will be used by the champions of natural selection."^[102] I. I. Shmal'gauzen not only followed his teacher's counsel but also became one of the most accomplished contributors to the grand theory of evolutionary synthesis. Severtsov's students, particularly Shmal'gauzen, helped abate the traditional conflict between genetics and Darwin's theory of organic evolution by making elaborate recommendations for an integrated approach to evolution. They accomplished this not by turning against their teacher but by adding to the breadth and depth of his theoretical insights.

Deeply aware of the need for bringing together Darwinian and genetic evolutionary strategies, Severtsov was convinced that neither Darwin's theory nor genetics was advanced enough to justify immediate work on such a project. He dedicated his life to preparing the Darwinian side of the evolutionary equation for a grand synthesis by giving it more depth and precision and by helping raise it to higher levels of scientific abstraction.

Severtsov had a logical and disciplined mind. In the intricate conceptual structure of his evolutionary morphology, only the notion of "regression" appeared to be insufficiently clarified and imprecisely stated, particularly as a unique mechanism of "biological progress." His extensive use of the adjective "morphophysiological" did more justice to morphology than to physiology. He did not make the historical orientation of the theory of phylembryogenesis and the structural orientation of morphology parts of a unified strategy in evolutionary research. Concentrating on the "how" rather than on the "why" of organic evolution, he showed much more interest in bringing genetics closer to Darwinism than in bringing Darwinism closer to genetics.^[103] Severtsov's achievements were, nonetheless, of major proportions. Particularly noteworthy

was his generally successful effort to raise evolutionary study to higher levels of conceptualization and to make morphology a central integrating link in the modern approaches to organic change. He succeeded in elevating the theory of biological evolution above the recurring and ever threatening intrusions of neovitalism and speculative branches of neo-Lamarckism. In all his studies, Severtsov adhered closely to the laws of evolution stated in the Origin of Species .

In reflecting on the history of evolutionary biology, Severtsov summed up his views on the history of Darwinian thought. Darwin, unlike Lamarck, was successful because the scientific community was ready to absorb his ideas, which "attracted talented and brilliant representatives of many sciences: the comparative anatomists Huxley and Weismann, the embryologists Balfour and A. O. Kovalevskii, and the paleontologists Cope, V. O. Kovalevskii, and Gaudry."^[104] In his opinion, the first ten to fifteen years after the publication of the Origin of Species produced such an abundance of great results that contemporaries became convinced that the salient points of the evolutionary theory were firmly established and that the future generations of biologists would be expected only "to fill in details." This did not happen, however. The deeper the biologists went into Darwin's theory, the more they became convinced that it needed much more than details giving added strength to the established principles. According to Severtsov, it also needed additional principles applicable to the newly carved out domains of inquiry. The new evolutionary biology grew in two directions: horizontally, by widening the base of evolutionary studies, and vertically, by endeavoring to reach higher levels of scientific abstraction. Severtsov distinguished himself primarily by his comprehensive effort to make morphology, as a core discipline of organic evolution, an elaborate network of scientific laws and principles.

Severtsov's heavy reliance on high theory was only one mode of defending and advancing Darwinian orthodoxy. N. V. Tsinger, a professor at the Novo-Aleksandriia Institute of Agriculture and Forestry, relied on a different mode. He devoted no time to building up an elaborate theoretical structure true to Darwin's basic principles. Working on a purely empirical level and taking Darwin's principle of natural selection for granted, he undertook to show how it worked in concrete situations. Particularly noted was his study of the origin of Camelina linicola, an annual false-flax plant producing small yellow flowers, which grows in fields under flax cultivation, a condition indicating that it is a relatively

new species. After a long study, Tsinger concluded that this plant has evolved from a xerophytic to a hydrophytic species, and that it no longer could revert to xerophytic existence.

Tsinger's study attracted particularly wide attention because it dealt with a unique case of natural selection. Tsinger concluded that one of the xerophytic Camelina plants of the family Cruciferae was the ancestor of C. linicola . The question was why the other Camelina species continued to live outside the cultivated flax fields. The answer was in the common technique of selecting flax seed for planting. The farmers usually relied on special sieves to isolate the large seed of flax from the smaller seed of undesirable wild plants. Of all seeds of wild plants, only those of the ancestor of C. linicola happened to be large enough to remain with flax seed during the sieving process; in due time they produced a new species that took on many characteristics of cultivated flax and became fully adapted to the wet habitat of flax fields. C. linicola, the new species, survived because it emerged victorious in its struggle for survival—which happened to be a struggle against human effort to eliminate it from its new habitat. This selection was not artificial, because "artificial selection"—at least the way Darwin knew it—refers to human effort to produce new varieties of domestic plants and animals. Nor was it natural: "natural selection"—at least as Darwin saw it—does not provide so much room for human interference. In one important respect, however, it was natural: it was clearly a product of the struggle for existence.^[105] Tsinger's study provided one of the rare empirical and direct descriptions of the work of "natural selection" as a mechanism of evolution. What Severtsov showed on a high theoretical level, Tsinger achieved on an empirical level: both produced evidence showing that the struggle for existence and natural selection are dynamic and flexible processes with infinite ramifications.

Darwinism as a World View

A strong group of scientists depended on philosophical metaphors in expressing their Darwinian affiliation. These scholars were not professionally conversant with the specific ramifications of evolutionary principles built into Darwinian thought. Nor were they necessarily involved in evolutionary research. They merely looked at the work of Darwin as a triumph of modern intellect and as a most sublime achievement of science as a body of knowledge, a method of thinking, and a world outlook. In this department Darwin's contributions found a great and

eloquent supporter in the famous neurophysiologist Ivan Pavlov. In "Experimental Psychology and Animal Psychopathology," a paper delivered at the Fourteenth International Congress of Medicine, held in Madrid in 1903, Pavlov professed his strict adherence to the Darwinian view of the scientific approach to the adaptation of organisms to the dynamics of environment. This approach had no use for the philosophical notion of teleology, a lure to vitalism.^[106] In a speech delivered in London in 1906, Pavlov identified Thomas Huxley as an energetic supporter of the theory of evolution, the "greatest idea" in biology.^[107] In a later speech he noted the profound influence of the Origin of Species on the intellectual world in general and on the scientific community in particular.^[108]

Pavlov's article "Natural Science and the Brain," delivered in December 1909 at the Twelfth Congress of Russian Naturalists and Physicians, appeared in In Memory of Darwin (1910), a collection of essays honoring the one-hundredth anniversary of Darwin's birth and the fiftieth anniversary of the publication of the Origin of Species . The article made no specific reference either to Darwin or to the theory of evolution. But that did not make much difference: important was the fact that a widely read and discussed book made Pavlov's sentimental and philosophical allegiance to Darwinism firmly documented and generally known. Loyal to Darwinian principles, he claimed that only an experimental study of animal adaptation to the external environment can produce scientific knowledge on the elementary modes of behavior, which Pavlov identified as "higher nervous activity."

In 1913, in a paper presented at the Moscow Scientific Society, Pavlov made his assessment of Darwin's place in modern science clear and forthright:

In all justice, Charles Darwin must be given the major credit for stimulating and inspiring the modern comparative study of the higher [psychic] manifestations of animal life. In the second half of the last century, as every educated person knows, his brilliant explanation of [organic] development fertilized the entire intellectual sector of human activity, particularly the biological branch of natural science. The hypothesis of the animal origin of man has led to an absorbing interest in the study of the higher manifestations of animal life. The post-Darwinian period faces the task of finding the best way to answer this question and to organize a study of the problem.^[109]

In 1916 Pavlov contributed a paper to a symposium honoring K. A. Timiriazev, the most ardent and consistent Russian Darwinist. Pavlov ended the paper by identifying Timiriazev as a "tireless champion of a

real scientific analysis in a region of biology" in which it was easy to stray along "false paths."^[110] By "real scientific analysis" Pavlov could have meant only a defense of Darwin's evolutionary views, the main theme of Timiriazev's involvement in biological scholarship. Pavlov and Timiriazev were united in a firm belief that neovitalism was a metaphysical aberration in biology and that physiology, depending exclusively on the experimental method, was the backbone of biology.

Although Pavlov's expressions of a favorable attitude toward Darwin's contributions did not usually go beyond parenthetical statements, they placed the eminent neurophysiologist solidly in the camp of Darwinism, bolstering its defenses and carrying its influence to a new domain of scholarly activity. At this time the Russian anti-Darwinists found it much easier to attack the ghost of Darwin than to challenge Pavlov's firm hold on the scientific community. At a time when Darwinism was besieged from all sides, Pavlov's admiring attitude toward Darwin's philosophy contributed immensely to the strength of a vital tradition in national science.

Despite his frequent testimonials, Pavlov did little to place his own research within an evolutionary framework. He did not accept Karl von Nägeli's challenging idea that the real study of organic evolution belonged to a physiology built on the model of Newtonian mechanics. Severtsov saw organisms as morphological unities and as systems of adaptive mechanisms responding to changes in the habitat. Neither Pavlov nor any other Russian scientist undertook a systematic and comprehensive study of the physiological unity of organisms as adaptive or evolutionary mechanisms. Without mentioning Pavlov by name, Severtsov pointed out the difference between the evolutionary bent of morphology and the nonevolutionary interest of physiology:

For a given species it is irrelevant whether one of its organs has performed the same function for both ancestors and descendants. What is relevant is whether the performance of this function has become more efficient in the struggle for existence. It is exactly here that our view differs from that of physiologists: they study the functions of organs per se, we study these functions as means that help individual species in their struggle for survival. The changing organs are only the tools that help the descendants of a given living form create biologically significant active or passive adaptation mechanisms.^[111]

During and immediately after World War I, Pavlov showed slight interest in linking the theory of conditioned reflexes to the Lamarckian principle of the inheritance of acquired characteristics.^[112] Subsequently, he stated publicly that he was not a partisan of the theory of the heredity

of conditioned reflexes.^[113] W. H. Gantt, Pavlov's American student, acknowledged his teacher's Lamarckian leanings, but he noted that Pavlov's "Lamarckism" consisted only of a few passing remarks. Working on the experimental foundations of the theory of unconditioned reflexes, Pavlov gave the problem of the inheritance of acquired characteristics only minor significance. Gantt thought that Darwin's and Pavlov's theories were mutually complementary: while Darwin treated adaptation of individual species to the habitat over long periods of time, Pavlov dealt with adaptation—by means of conditioned reflexes—within the life-spans of individual organisms.^[114] In Severtsov's terminology, whereas Darwin's approach was historical, Pavlov opted for an essentially ahistorical approach.

Among the contributors to In Memory of Darwin the physicist N. A. Umov, a well-known professor at Moscow University, enjoyed an enviable reputation as one of the earliest Russian commentators on quantum and relativity theories. An expert in the theory of earth magnetism, the diffusion of aqueous solutions, and optical qualities of opaque media, he expressed clearly articulated philosophical views, which in their total effect can be labeled scientific humanism. Like several other Russian scientists, including I. I. Mechnikov and V. I. Vernadskii, he equated the evolution of human intelligence with the steady expansion of a force of cosmic proportions.^[115] He was the moving force in the founding of the Ledentsov Society, the first serious effort in Russia to set up a private foundation providing financial support for research in the natural sciences and technology. Umov's attitude was best expressed in the following statement:

The great thinkers Helmholtz and Darwin have removed the barriers from the roads leading to the understanding of human origin and life. The first disproved the existence of a special [vital] force in living nature . . . ; the second adduced incontrovertible evidence in support of genetic bonds between man and animal. New scientific studies have carried the idea of evolution to the study of inorganic nature as well. In consequence, science has shown that without exception all natural phenomena, regardless of their inner organization, are rational, that is, open to human reason for examination. Although there are secrets which cannot be decoded at this rime, [we must remember that] everything is part of nature—that there are no secrets outside nature.^[116]

In an earlier paper, clearly inspired by Darwin's evolutionary idea, Umov postulated "the third law of thermodynamics," which worked in the opposite direction from the law of entropy. The processes of life, he said, lead to an increase in both the quantity and the harmony of the

organic world. In the "selective adaptation" of organisms he saw the real propelling force of this law. In the living universe, "selective adaptation is a weapon in the struggle against both disharmony and entropy"—it is Maxwell's demon selecting favorite molecules.^[117] Umov did not pursue his intriguing ideas; he merely wanted to show how the various branches of modern physics combined with the grand idea of organic evolution to create a world view permeated by scientific optimism. He rejected vitalism for its negation of the possibility of creating a unified picture of nature.

Pavlov and Umov shared a cosmic outlook dominated by an organic blend of Darwinian evolutionism and the Newtonian mechanistic view of nature. P. P. Lazarev, a new physicist with old ideas, went so far as to claim that Newtonian physics was not only a source of models for a scientific study of organic evolution but also a fountain of information corroborating the basic principles of Darwin's theory. In an earlier article published in 1915 in Priroda he cited Helmholtz to show that Newtonian physics, which he thought was the high point in the evolution of science, gave full support to Darwin's notion of the purposive adaptation of organisms to their environment. He also credited Boltzmann with having adduced "physicochemical" arguments in favor of the struggle for existence as a prime mover of evolution.^[118]

More than any other Russian scholar, Maksim Kovalevskii carried Darwin's ideas to the domain of sociology. In his studies of the history and social organization of the obshchina and in his analysis of the Caucasian legal customs he expressed himself in favor of an evolutionary approach to the universal history of human society, based on the use of the comparative method as the most reliable tool of sociological inquiry. In 1890, in a monograph on the origin of the family and private property, he noted the indebtedness of modern sociology and social history to Darwin's biological contributions. Darwin's "great law of evolution," he observed, exercised a growing influence on the study of social phenomena and had become a guiding force in "the philosophy of history and in the sciences of religion, law, and morality."^[119]

In a later study Kovalevskii offered a detailed assessment of the influence of Darwinian biological thought on the development of modern social theory. He made four points. First, Darwin's major contribution was in influencing the emergence of an empirical approach to social phenomena and in adopting causal analysis as a method of sociological explanation. Second, there was no modern sociological orientation free of the influence of Darwin, his precursors, and his followers.^[120] From the

first published essays of Herbert Spencer to the contemporary French school, which emphasized both struggle and solidarity as the nexus of social existence, all sociology, according to Kovalevskii, built upon biological foundations, and all sociological laws appeared as variations on the laws that, in Darwin's opinion, explained the origin of species.^[121] Third, natural selection required major modifications to become a sociologically useful notion. Durkheim's "organic solidarity," Petr Kropotkin's "mutual aid," Lester Ward's "psychological method," and G. Tarde's "opposition universelle " indicated the preferred sociological responses to Darwin's ideas. Fourth, by planning for a society devoid of class struggle, Marx transformed sociology from a budding science into a utopia. No doubt Kovalevskii was reading his theoretical impulses and social vision into the sociological empire of Darwinism. He translated Darwin's science into his own world view. Nonetheless, he was generally considered the leading Russian sociologist of his time, and it came as no surprise in 1914 when the St. Petersburg Academy of Sciences elected him to full membership.

Russian historians, concerned with the methodological and theoretical problems of their discipline, made a habit of carrying Darwin's suggestive ideas into their own academic fields. P. G. Vinogradov, whose expertise in the social history of medieval England earned him an academic position at Oxford University, believed that the notion of evolution, as applied to both nature and society, stood out as the greatest and potentially most fertile product of the modern scientific mind. In his view, "natural science began to exercise a real influence on the study of history only after it absorbed the ideas of transformation and development and adopted the historical method."^[122] The main contribution of Darwinism consisted not only of making evolution a central problem in biology but also of pointing out its significance for the social sciences. While Darwin concentrated on biological change, his followers laid the foundations for a comprehensive "philosophical explanation of the theory of evolution."^[123] The future of human society, as Vinogradov saw it, depended primarily on knowledge of the universal laws of nature.

The Ministry of Public Education kept particularly vigilant control over the selection of professors who taught philosophy on the university level. During the 1890s it became clear that only persons identified with idealistic metaphysics were allowed to hold the title of professor of philosophy. For this reason there was not a single philosophy professor in Russian universities willing to match the forthright assertion of John Dewey, a Columbia University professor of philosophy, that the real

strength of Darwinian influence on philosophy was in conquering "the phenomena of life for the principle of transition," and in freeing "the new logic for application to mind and morals and life." Darwin, Dewey continued, "emancipated, once for all, genetic and experimental ideas as an organon of asking questions and looking for explanations."^[124] Nor did Russia produce a single university professor of philosophy ready to agree with Harald Höffding, professor of philosophy at the University of Copenhagen, who wrote that Darwin, whose contributions he valued as much as those of Copernicus and Newton, deserved full credit for pointing out the verifiable base of the notion of the origin of species.^[125]

Outside the universities, the philosophical situation was very different. Idealistic metaphysicists were here, too, but so were the writers favoring a close alliance of philosophy and science. One of the more accomplished and influential of these writers was Mikhail Mikhailovich Filippov, editor of the journal Science Review and recipient of a doctorate in natural philosophy from Heidelberg University in 1892, with a dissertation on a specific aspect of differential equations. In 1895–98 Filippov published Philosophy of Reality, a two-volume synthesis of philosophy and science. He viewed philosophy as a systematic study of the basic principles and ideas of contemporary science and as an effort to create an "integrated scientific world view."^[126] He operated on the assumption that his approach was the only acceptable path to sound philosophical discourse and that philosophers must rely primarily on scientific knowledge. The Philosophy of Reality presents the ideal of evolution as the most basic and penetrating link between individual sciences. Without evolution, the unity of scientific disciplines could not be based on concrete knowledge. Such topics as cosmogony, evolutionary paleontology, organic evolution, and psychological and sociological evolution form the heart of the study. The huge volumes stand out as a critical synthesis of modern scientific knowledge.

The study has some major flaws; for example, it needs a more precise structure of individual chapters, its selection of scientists who contributed to the elucidation of the idea of evolution tends to be fortuitous, and it does not give a clear picture of the relative significance of individual subsidiary topics. Despite these omissions, the study was a major success, primarily because it helped counterbalance the mysticism of academic philosophy. It introduced Russia to the fresh rays of modern philosophy grounded in science and opposed to metaphysical obscurantism. The Philosophy of Reality depicted the triumph of the evolution-

ary principle in modern scientific thought, introduced Darwin's work as a fundamental contribution to modern philosophy and to a new world outlook, and presented the main trends in the development of evolutionary thought after the publication of the Origin of Species . Written simply and lucidly, it gave the general reader a comprehensive idea of evolution as the cornerstone of modern secular thought.

Filippov belonged to the group of evolutionists who favored Lamarckism no less than Darwinism. He saw only a limited use for the struggle for existence and natural selection in the evolutionary process, but he was ready to admit that the triumph of the evolutionary principle owed more to Darwin than to any other scientist. It was Darwin who made the universality of transformism both a scientific and a philosophical conception and who opened many new avenues for a future elaboration of the evolutionary idea. Above all, Filippov showed that negative criticism of the struggle for existence and natural selection should in no way interfere with the recognition of Darwin as one of the greatest scientists of all time. Despite the striking "weaknesses" of individual principles built into his theory, Darwin won the day because he allowed no room for "forces and impulses acting independently of the known laws of nature," which made his theory acceptable to "a majority of natural scientists."^[127]