The Darwinian revolution in Germany: from evolutionary morphology to the modern synthesis

ENDE-542; No. of Pages 12

The Darwinian revolution in Germany:from evolutionary morphology to themodern synthesisGeorgy S. Levit1,2,3,*, Uwe Hossfeld3,2 and Lennart Olsson4

1 Bundesforschungsinstitut fur Tiergesundheit (FLI), Naumburger Str. 96a, 07743 Jena, Germany2 ITMO University, Lomonosov str. 9, 191002 St. Petersburg, Russia3 Arbeitsgruppe Biologiedidaktik, Biologisch-Pharmazeutische Fakultat, Friedrich-Schiller-Universitat Jena, Am Steiger 3,

Bienenhaus, D-07743 Jena, Germany4 Institut fur Spezielle Zoologie und Evolutionsbiologie mit Phyletischem Museum, Friedrich-Schiller-Universitat Jena, Erbertstr. 1,

D-07743 Jena, Germany

Endeavour Vol. xxx No. x Full text provided by www.sciencedirect.com

ScienceDirect

The Darwinian revolution in the German speakinglands was the result of a variety of influences anddisciplinary convergences. One of the paths led frompre-Darwinian comparative morphology via Darwin-ian and Lamarckian evolutionary morphology to theModern Synthesis. Our research demonstrates thatthere was no immediate replacement of one para-digm by another as described in the classical workof Thomas Kuhn. Rather, the development of novelconceptual structures looked like a Russian‘matryoshka doll’ consisting of an over-arching‘meta-paradigm’ embracing conceptual structuresof ever smaller scale. Such a meta-paradigm for Ger-man life sciences was initially established by JohannWolfgang von Goethe, which determined the specific-ity of German evolutionism throughout the 2nd halfof the 19th and well into the 20th century.

IntroductionIn the early 1960s Thomas Kuhn1 contributed to the ‘crisis ofrationality’2 with his hypothesis that science develops bymeans of paradigmatic shifts. He challenged the positivistconcept of cumulative and continuous scientific progress.According to Kuhn, the relation between two succeedingscientific traditions ‘separated by a scientific revolution’ ischaracterized by the concept of incommensurability thatconstrains the interpretation of science as a cumulative,staidly progressing enterprise.3 The most fundamental as-pect of incommensurability is that ‘the proponents of com-peting paradigms practice their trades in different worlds’.4

*Corresponding author at: Bundesforschungsinstitut fu r Tiergesundheit (FLI),Naumburger Str. 96a, 07743 Jena, Germany.

1 Kuhn T. The Structure of Scientific Revolutions. Chicago: The University ofChicago Press, 1996.

2 Hacking I. Representing and Intervening. Cambridge: Cambridge UniversityPress, 1983, p. 1.

3 Hoyningen-Huene P. Three Biographies: Kuhn, Feyerabend and Incommensura-bility. In: Harris RA (ed.) Rhetoric and Incommensurability. West Lafayette, Indiana:Parlor Press, 2005, p. 152.

4 Kuhn T. The Structure of Scientific Revolutions. Chicago: The University ofChicago Press, 1996, p. 150.

Please cite this article in press as: Levit, G.S., et al., The Darwinian revolution in Germany: fr10.1016/j.endeavour.2014.10.010

www.sciencedirect.com 0160-9327/� 2014 Published by Elsevier Ltd. http://dx.doi.org/10.101

Peter Galison5 opposed both positivists and anti-positi-vists, introducing the term ‘trading zone’ to demonstrate theway science and innovation correlate. As nicely summarizedby Collins et al. (2007): ‘His purpose was to resolve theproblem of incommensurability between Kuhnian para-digms: How do scientists communicate if paradigms areincommensurable? Galison’s approach has two legs. Thefirst leg denies that scientific paradigms are as monolithicas Kuhn says. The second leg uses the metaphor of thetrading zone to explain how communication is managedwhere there is a degree of incommensurability’.6 Galison,first of all, studied the relationships between theoreticalscience and experimental work and came to the conclusionthat the laboratory is a place where ‘the local coordinationbetween beliefs and action takes place’.7 In other words,Galison described the interaction between the level of theoryand ‘lower’ experimental and even instrumentals levels.

By contrast, we are interested in the relationshipsbetween theoretical and metatheoretical levels. We willargue that the Darwinian theory (theories) interacted withnational research traditions (metatheoretical level) andthe resulting conceptual body represented an amalgam-ation of a metatheoretical framework with the ‘purelyscientific’ theoretical beliefs such as the theory of naturalselection. We will demonstrate this using the example ofthe German research tradition in evolutionary biology.

There are two important assumptions underlying ourconsiderations. First, we do not support the idea that theDarwinian revolution is a homegrown phenomenon to beanalyzed exclusively in terms of British intellectualhistory. The very fact of the rapid spread of Darwinism

5 E.g.: Galison, P. Image and Logic: A Material Culture of Microphysics. Chicago:Chicago University Press, 1997; Galison, P. In: Biagioli M. (ed.) Trading Zone:Coordinating Action and Belief. The Science Studies Reader. New York: Routledge,1999, pp. 137–160.

6 Collins H., Evans R., Gorman R. Trading zones and interactional expertise.Studies in History and Philosophy of Science, Special Issue – Case Studies of Expertiseand Experience, Vol. 38, No. 4, pp. 657–66, 2007.

7 Galison, P. In: Biagioli M. (ed.) Trading Zone: Coordinating Action and Belief. TheScience Studies Reader. New York: Routledge, 1999, pp. 137–160.

om evolutionary morphology to the modern synthesis, Endeavour (2014), http://dx.doi.org/

6/j.endeavour.2014.10.010

http://dx.doi.org/10.1016/j.endeavour.2014.10.010


http://www.sciencedirect.com/science/journal/01609327


12 Darwin Ch. Uber die Entstehung der Arten im Thier- und Pflanzen-Reich durchnatu rliche Zu chtung, oder Erhaltung der vervollkommneten Rassen im Kampfe um’sDaseyn. Trans. Heinrich Bronn. Stuttgart: E. Schweizerbart, 1960; Gliboff S. TheCase of Paul Kammerer: Evolution and Experimentation in the Early TwentiethCentury,’’ Journal of the History of Biology 39: 525–563, 2006.13 Jahn I. ,,Biologie‘‘ als allgemeine Lebenslehre. In: Jahn I. (ed.) Geschichte der

2 Endeavour Vol. xxx No. x


in such different cultural-political landscapes as the Ger-man lands8 and the Russian Empire9 demonstrates that thecontinental intellectual culture was ready to accept funda-mental changes in the life sciences. The concept of theDarwinian Revolution as an intercultural and internationalmovement can be approached from various perspectives.Robert Richards10 famously argued that German romanti-cism shaped Darwin’s worldview to a very significant extent.Richards concentrated on how continental influences guidedthe theoretical evolution of the Englishman’s ideas. Ourperspective differs from that of Richards. We claim thatGerman romantic biology strongly influenced the paths ofDarwinian revolution in the German lands. The impact wasso strong that it can be traced right into the time of theModern Synthesis. Our perspective is supplementary toRichard’s conclusions. Both approaches suggest that ‘theDarwinian Revolution’ goes far beyond Down, and thatintercultural influences are parts of the same narrativeand are obligatory for an understanding of the growth ofDarwinism both inside the English-speaking world andoutside of it. Second, we propose that meta-paradigmscan exist in various national intellectual traditions. Thesemeta-paradigms remain invisible when we constrain ouranalysis to one tradition (e.g., British), but become visible inthe light of a comparative analysis.

We will demonstrate that the change of the world-view,which took place during the Darwinian revolution inGermany, corresponded rather to a cumulative model thanto Kuhn’s incommensurability model. However, this is nota positivist cumulative model. Crucial architects of Ger-man Darwinian evolutionism built on pre-revolutionarydevelopments not only in terms of empirical data andconceptual details, but most importantly in terms of con-sequent development of coherent fundamental methodo-logical and ontological assumptions. In other words, manyof the pre- and post-Darwinians shared a common world-view, which served as a basis for the evolution of theirresearch programmes (a meta-paradigm). Second, we willshow that this worldview, initially outlined by Goethe,persisted until the completion of the Modern Synthesisand beyond in the German-speaking countries. Third, wewill argue that crucial figures of the First and SecondDarwinian revolutions in Germany (Ernst Haeckel, VictorFranz, Bernhard Rensch) saw themselves as bearers of theGoethean tradition in biology. Since German evolutionisminitially developed mostly within the field of morphology,we will concentrate on the growth of evolutionary morphol-ogy, before moving on to the Modern Synthesis in theGerman-speaking lands.

Goethe’s morphological revolutionThe explosive growth of Darwinian thought in Germanyafter the publication of the Origin of Species11 and its

8 Junker T., Hossfeld U. Die Entdeckung der Evolution. Eine revolutionare Theorieund ihre Geschichte. 2nd ed. WBG, Darmstadt, 2009.

9 Levit G.S. The roots of Evo-Devo in Russia: is there a characteristic ‘‘Russiantradition’’? Theory in Biosciences, 4:131–148, 2007.10 Richards R.J. The Romantic Conception of Life: Science and Philosophy in the Age

of Goethe. Chicago & London: The University of Chicago Press, 2002.11 Darwin Ch. On the Origin of Species by Means of Natural Selection, or the

Preservation of Favoured Races in the Struggle for Life. 1st Ed. London: John Murray,1859.


www.sciencedirect.com

German translation12 was enabled by pre-Darwiniandevelopments. Arguably the most important of thesewas the growth of pre-Darwinian morphology and alliedfields such as embryology. Johann Wolfgang von Goetheplayed a paradigmatic role for the science of biologicalform. In fact, the very term ‘morphology’ was firstemployed in 1796 by Goethe to denote a sub-discipline ofthe science of living beings, although Goethe was not thefirst to bring the term to print.13 Goethe defined morpholo-gy as a science of morphing: metamorphosis (Verwan-dlungslehre). As a ‘low Church’, his morphology was acomparative science studying differences and similaritiesbetween various organic structures. Yet morphology as a‘high Church’ had as its subject a moving, emergent anddisappearing Gestalt: ‘The doctrine of Metamorphosis isthe clue to all signs of Nature [Zeichen der Natur]’.14 ForGoethe, morphology was a fundamental enquiry into themost essential features of life and ultimately of the uni-verse. The ‘high Church’ methodological principles guidedempirical research and principles of the ‘low Church’.

Considering that distinction, one can outline severalfundamental methodological principles which guidedGoethe’s morphology.

The first such principle is the idea of the type (arche-type). The search for a vertebrate type resulted, for exam-ple, in the discovery of the intermaxillary bone in man.15

Goethe’s intention was to compare various vertebrate ‘os-teological’ structures to search for the general vertebratearchetype: ‘Goethe tried to reach a clear idea of the verte-brate archetype not only from wide induction but also froma study of function. A bone which is not only present inmost vertebrates but also obviously serves a very impor-tant function is likely-for both these reasons-to belong tothe archetype’.16 The ‘archetype’ (‘Der Typus’, the termusually translated as ‘archetype’) was for Goethe a ‘mainthread’ running through the labyrinth of Gestalts, a gen-eral scheme to be found as a result of empirical general-isations. In the works of 1790s devoted to the structure ofanimals, Goethe put forward the idea of the archetype as apattern to be used in comparative morphology, but mostimportantly he saw the archetype as ‘a dynamic forceactually resident in nature’,17 as a potentiality: ‘. . .ananatomical archetype will be suggested here, a generalpicture containing the forms of all animals as potential, oneof which will guide us to an orderly description of eachanimal. [. . .] The mere idea of an archetype in generalimplies that no particular animal can be used as our point

Biologie. Jena: Gustav Fischer 1998, p. 279; Richards R.J. The Romantic Conception ofLife: Science and Philosophy in the Age of Goethe. Chicago & London: The Universityof Chicago Press, 2002, p. 453.14 Cited and translated from: Jahn I. ‘‘Biologie’’ als allgemeine Lebenslehre. In: Jahn

I. (ed.) Geschichte der Biologie. Jena: Gustav Fischer, 1998, p. 279.15 Goethe J.W. Scientific Studies. Ed. by D. Miller. N.Y.: Suhrkamp, 1988, pp. 111–

116.16 Wells G.A. Goethe and the Intermaxillary Bone. The British Journal for the

History of Science, 3(4): 348–361, 1967.17 Richards R.J. The Romantic Conception of Life: Science and Philosophy in the Age

of Goethe. Chicago & London: The University of Chicago Press, 2002, p. 440.




Endeavour Vol. xxx No. x 3


of comparison; the particular can never serve as a measurefor the whole’.18

The second methodological principle, important in ourcontext, was his pantheism, which was incorporated intohis Spinozism. In his later years Goethe abandoned the‘Newtonian God’, who only impels the world from theoutside, and turned towards Spinoza’s Ethics and adaptedthe ‘God in Nature, Nature in God’ principle: ‘In the Deussive Natura of Spinoza the God is not lost behind matter.He is present and lives, as the inner side of the same greatwhole that to our senses appears as nature’.19 In otherwords, Goethe found in Spinoza’s thought a system thatreflected the core of his own worldview, the idea of aneternal unity of the Universe including the unity of Godand Nature.20

Finally, Goethe advocated a cognitive method which hedescribed in a short essay Judgment through intuitiveperception.21 Goethe undertakes a short critical analysisof Kant’s thesis that human cognition is restrained by the‘discursive judgement’ (logical, analytical thought) as op-posed to intuitive ‘viewing of a whole to the parts’. In otherwords Goethe claims that ‘intuitive perception of a whole isa valid scientific method’.22 In A Study based on SpinozaGoethe abandoned empiricism and emphasised that aliving thing must be measured by its own gauge. Itsessence is spiritual and cannot be found through thesenses.23

Goethe’s morphological studies certainly containedmore than the three aspects described above, but thesethree parts of his worldview are crucial for our purposes.All three parts are interconnected. Thus, the search for anarchetype presupposes the use of intuitive perception, andthe presence of the divine in nature was an immanent partof experience. As Richards puts it: ‘. . .if archetypal ideasare necessary for our experience of organic nature, thenthey must be constituents of that archetype’.24 And, since‘creative ideas are resident in nature’, Goethe’s Spinozismbecomes a trinity of God, nature, and intellect.25 Goethe’spantheism is at the heart of his Spinozism and it is viaGoethe that it enters German Darwinian evolutionism.

At the same time, Goethe’s comparative morphologywasn’t only a ‘Faustian’ project aimed at the cognition ofthe final causes of the Universe, but also an appliedscience. The best example of its practical value was theestablishment of the Veterinary School in Jena (in 1816)under Goethe’s immediate patronage.26 Goethe himselfsaw this site as a place for conducting research of bothpractical and theoretical relevance.

18 Goethe J.W. Scientific Studies. Ed. by D. Miller. N.Y.: Suhrkamp, 1988, p. 118.19 Lange A.F. History of Materialism and Criticism of its Present Importance. Trans.

by Thomas E.C. Vol. II. Boston: Houghton, Osgood, and Co., 1880, p. 148.20 Troll W. Deus sive natura: Goethe und Spinoza. In: Troll W. (ed.) Goethes

Morphologische Schriften. Jena: Eugen Diederichs Verlag, 1932, p. 15–33.21 Goethe J.W. Scientific Studies. Ed. by D. Miller. N.Y.: Suhrkamp, 1988, pp. 31–32.22 Heitler W. Goethean Science. In: Seamon D. & Zajonc A. (eds.) Goethe’s Way of

Science. N.Y.: State University of New York Press, 1998, p. 65.23 Goethe J.W. Scientific Studies. Ed. by D. Miller. N.Y.: Suhrkamp, 1988.24 Richards R.J. The Romantic Conception of Life: Science and Philosophy in the Age

of Goethe. Chicago & London: The University of Chicago Press, 2002, p. 490.25 Ibid, pp. 506, 490.26 Schonherr W. Die Verwaltungstatigkeit Goethe’s im Auftrage des Großherzogs

Carl August und die Verdienste des Dichters um Gru ndung und Entwicklung derVeterinaranstalt in Jena. Wissenschaftliche Zeitschrift der FSU Jena. Mathematisch-Naturwissenschaftliche Reihe. Heft 3. Jahrgang 15, 1966, p. 373–379.



Haeckel walked in Goethe’s footstepsThe importance of morphology for the growth of evolution-ary theory was aphoristically phrased by Robert Richardsin his claim that ‘evolutionary theory was Goethean mor-phology running on geological time’.27 In fact, however,Goethe inspired both Darwinian and Lamarckian evolu-tionism as well as ‘counter-revolutionary’ idealistic mor-phology.

If we accept that the first period in the development ofevolutionary morphology in Germany was determined byErnst Haeckel (1834–1919) and Carl Gegenbaur (1826–1903), then the second period can be exemplified by theworks of Victor Franz (1883–1950), Hans Boker (1886–1939) and Alexej Sewertzoff (1866–1936). Yet, evolution-ary (historical) methodology was not a single player, nei-ther in the first nor in the second period in the German-speaking world. As such, evolutionary morphology co-existed with the idealistic (structuralist) methodologicaltradition. Moreover, evolutionary morphology was not amethodological monolith, because Darwinism itself wassplit into neo- and old school-Darwinism, and purely La-marckian schools were accompanied by further methodo-logical doctrines such as holism. The idealists, such asWilhelm Troll (1897–1978), Edgar Dacque (1878–1945)and Adolf Naef (1883–1949), Adolf Portmann (1897–1982), the Lamarckian Hans Boker, and the DarwinianVictor Franz all contributed significantly to the empiricalstudy of morphology. Despite methodological discrepan-cies, all of them embraced Goethe and explicitly countedhis doctrines as a basis for their own methodologies.

This is especially true for Ernst Haeckel, the majordriving force of the first Darwinian revolution: ‘Thus na-ture herself, in Goethe’s view, was a creative font thatshowered diversity, though along unified trajectories. Thisfundamental view would underlay all of Haeckel’s work inscience’.28

Haeckel was inspired by his older colleague in Jena, theanatomist Carl Gegenbaur, who had been instrumental inbringing Haeckel to Jena as a professor. Gegenbaur wrotea number of research monographs and textbooks, whichwere seen as a model of critical investigation based on anextensive collection of facts, something Haeckel admired.Gegenbaur pioneered investigations into, e.g., vertebratehead development in an evolutionary context and incorpo-rated an evolutionary view in his later work.29 Both Gegen-baur and Haeckel contributed importantly to creating anevolutionary morphology, specializing in vertebrates andinvertebrates, respectively. But it was Haeckel who incor-porated morphological and evolutionary studies into abroader philosophical context and tried to create an all-embracing world-view of monistic pantheism. Goetheanpantheism underlies Haeckel’s monism, while monismbuilds a framework for his evolutionism. Haeckel alwaysemphasised this genetic connection to Goethe and referredto the evolutionary theory as the theory created by

27 Richards R.J. The Romantic Conception of Life: Science and Philosophy in the Ageof Goethe. Chicago & London: The University of Chicago Press, 2002, p. 407.28 Richards R.J. The Tragic Sense of Life. Ernst Haeckel and the Struggle over

Evolutionary Thought. Chicago: The University of Chicago Press, 2008, p. 36.29 Hossfeld U., Olsson L., Breidbach O. (ed.) Carl Gegenbaur and evolutionary

morphology. Theory Biosci, vol. 122, Heft 2/3, 2003.




Figure 1. Entry of the Phyletic Museum in Jena (1910) with a hand-written note by

Haeckel. One can see a Goethe citation on a ceiling ledger (1908): ‘Wer Wissenschaft

und Kunst besitzt, hat auch Religion, wer jene beiden nicht besitzt, der habe Religion’

(Whoever possesses both science and art, possesses religion too; whoever

possesses neither science nor art, let them have religion) [EHH Archive, Jena].

Figure 2. Advertisement postcard of the First Monist Congress in Hamburg (1911)

[EHH Archive, Jena].

Figure 3. A drawing with Goethe and Friedrich Schiller, Ex Libris Ernst Haeckel

(private collection Uwe Hossfeld).



‘Darwin, Goethe and Lamarck’, and only ‘reformed byDarwin’.30 In Generelle Morphologie Haeckel emphasisedthat ‘both Lamarck and Goethe already articulated mostimportant claims of the theory of descent with all clarity’31

and even tried to convince Darwin that Goethe ‘had em-braced the rudiments of transformation theory’ (Fig. 1).32

Monism is a doctrine trying to reduce the manifoldnessof the universe to a single explanatory principle. As aworldview, monism has the ambition to explicate the mostbasic principles of being. The term was coined by ChristianWolff (1679–1754) to label a philosophy postulating thatthe world can be explained by only one basic substance(matter, spirit, soul). In the 2nd half of the 19th centurymonism takes on its contemporary meaning of a philosophyclaiming the unity of the universe as a fundamental condi-tion of reality, as well as reducibility of diversity to thepostulated unity.33 Around 1900 a heterogeneous move-ment takes form, which became known as ‘naturalisticmonism’, and tries to integrate natural science and mo-nism and to develop a monistic ethics. Haeckel, along withother influential figures such as Wilhelm Ostwald (1853–1932) und Auguste Forel (1848–1931), attempted to asso-ciate monism with natural sciences (Fig. 2).34

For Haeckel, the most fundamental principle of monismis the Law of Substance (Substanzgesetz). In Weltrathsel35

(Haeckel, 1899) Haeckel explains that it combines Lavoi-sier’s Law of the Conservation of Mass and Meyer undHelmholtz’ Law of the Conservation of Energy. In Lebens-wunder36 (Haeckel, 1904) Haeckel introduces a third

30 Haeckel E. Natu rliche Schopfungsgeschichte. Gemeinverstandliche wissenschaf-tliche Vortrage u ber die Entwickelungslehre im allgemeinen und diejenige vonDarwin, Lamarck und Goethe. Berlin: Georg Reimer, 1868; Kleeberg B. God-NatureProgressing: Natural Theology in German Monism. Science in Context 20(3): 537–569,2007.31 Haeckel E. Generelle Morphologie der Organismen. Band I. Berlin: Georg Reimer,

1866, p. 69.32 Richards R.J. The Tragic Sense of Life. Ernst Haeckel and the Struggle over

Evolutionary Thought. Chicago: The University of Chicago Press, 2008, p. 119.33 Hillermann A., Hu gli A. Stichwort Monismus. In: Ritter J., Gru nder K. (Hrsg.):

Historisches Worterbuch der Philosophie. Band 6. Basel, Stuttgart: Schwabe, 1984.34 Ziche P. (ed.) Monismus um 1900: Wissenschaftskultur und Weltanschauung.

Ernst-Haeckel-Haus-Studien 4. Berlin: VWB Verlag 2000.35 Haeckel E. Die Weltratsel. Bonn: Emil Strauß, 1899.36 Haeckel E. Die Lebenswunder. Stuttgart: Alfred Kroener, 1904.



element, the principle of perception, the psychoma. In1914 he brings together all three attributes [Grundei-genschaften] of the substance: the space occupying matter,the acting energy and the perceiving psychoma.37 The lastcategory was developed under the influence of Ernst Mach(1838–1916) and Max Verworn (1863–1921). The psycho-somatic becomes a fundamental principle of his panthe-ism.38 Proceeding from Haeckel’s theory of substance,Spinozism and the monistic concept of energy, Verworncame to the conclusion that a coherent monistic worldviewcan only be substantiated as psychomonism.39 The idea ofpsychomonism remained influential in Germany even atthe time of the Modern Synthesis.

For Haeckel, Goethe was an inspiration to build ageneral worldview (monism), to create a general theoryof organic life, to develop methodological instruments40

and to describe the basic principles of evolutionary

37 Haeckel E. Gott-Natur (Theophysis). Leipzig: Alfred Kroener Verlag, 1914, p. 3.38 Weber H. Monistische und antimonistische Weltanschauung. Ernst-Haeckel-

Haus-Studien 1. Berlin: VWB Verlag, 2000.39 Verworn M. Naturwissenschaft und Weltanschauung. Leipzig: Barth, 1904.40 Such as analysis and synthesis, see e.g. Haeckel E. Generelle Morphologie der

Organismen. Band I. Berlin: Georg Reimer, 1866, p. 74.






morphology, because it was Goethe who ‘according toHaeckel, established the fundamental principles of mor-phology, especially the proposal that various animal andplant characters could be understood as variations on somebasic types’ (Fig. 3).41

Post-Haeckelian morphology in GermanyIn 1908 Haeckel retired from his position as Director of theInstitute of Zoology and Jena University offered the posi-tion to Ludwig Plate (1862–1937). Plate was one of themost important figures in the ‘pre-synthetic’ period (firstthird of the 20th century) of continental European evolu-tionary biology. Plate developed a synthetic approach thathe called ‘old-school Darwinism’.42 He campaigned for arevival of the ‘original Darwinism’ that combined selection-ism with neo-Lamarckian ideas (factors that were impor-tant also for Darwin and Haeckel), and was seen by manycontemporaries worldwide as a proper advocate of Darwin-ism.43 Plate’s empirical as well as his theoretical works hadan enormous impact both during his life-time and after;they are still cited in the morphological literature.44 Platewas certainly committed to monistic evolutionary theory inHaeckel’s sense, just like many of Haeckel’s followers and‘old-schoolers’ such as Richard Semon (1859–1918) andPaul Kammerer (1880–1926).45 As a founding member ofthe Monist League, Plate departed from Haeckelian anti-religious propaganda, but adhered to the basic lines of histheory of descent.

Plate’s successor in Jena was Victor Franz, known asHaeckel’s academic grandson.46 As a zoomorphologist,Franz carried the strictly selectionist version of the Haeck-elian tradition further. Franz had a very broad educationin histology as well as morphology and physiology (underthe tutelage of Arnold Lang and Willy Ku kenthal), whichenabled him to do interdisciplinary work in evolutionarybiology. He had originally belonged to the camp (the so-called ‘Vervollkommnungsnegierer’), which denied thatevolution is progressive, producing ever more perfectorganisms.47 From 1910 onward, however, he changedhis mind and tried to give the concept of ‘Vervollkomm-nung’ (improvement) scientific content. He thereby explic-itly placed himself in a tradition that includes Goethe,Haeckel, Karl Ernst von Baer (1792–1876), Plate, andKammerer.48 Largely building upon Haeckel’s ideas, Franz

41 Richards R.J. The Tragic Sense of Life. Ernst Haeckel and the Struggle overEvolutionary Thought. Chicago: The University of Chicago Press, 2008, p. 119.42 As opposed to the neo-Darwinism of Wallace, Weismann, and Galton – see: Plate

L. Darwinsches Selectionsprinzip und Probleme der Artbildung. Ein Handbuch desDarwinismus. Leipzig: Verlag von Wilhelm Engelmann, 1908, p. 8.43 Levit G.S., Hossfeld U. The Forgotten ‘‘Old Darwinian’’ Synthesis: The Evolution-

ary Theory of Ludwig H. Plate (1862–1937) NTM International Journal of History andEthics of Natural Sciences, Technology and Medicine, 14:9–25, 2006.44 E.g.: Vorster W., Starck J.M. Anatomy of the middle ear of the Japanese crane

Grus japonensis (Grui- dae: Aves) Journal of Morphology 257(3): 260–269, 2003;Reynolds P.D. The scaphopoda. Advances in Marine Biology, 42:137–236, 2002.45 Gliboff S. The Case of Paul Kammerer: Evolution and Experimentation in the

Early Twentieth Century,’’ Journal of the History of Biology 39: 525–563, 2006.46 Hossfeld U, Olsson L The road from Haeckel. The Jena tradition in evolutionary

morphology and the origin of ,,evo-devo‘‘. Biol Phil 18:285–307, 2003.47 Franz, V. Uber Hoch und Niedrig im Tierreiche, Aus der Natur 3, 243–249, 1907;

Franz, V. Die Welt des Lebens in objektiver, nicht-anthropozentrischer Betrachtung,Verlag von J. A. Barth, Leipzig, 1907.48 Franz V. Die Vervollkommnung in der lebenden Natur. Jena: Gustav Fischer

Verlag, 1920; Haeckel E. Generelle Morphologie der Organismen. Band I. Berlin:Georg Reimer, 1866, pp. 370, 550.



formulated a concept of ‘improvement’ in 1911, and in 1920 a‘law of the superiority of differentiation and centralisation’.Between 1920 and 1935, he published a number of papers ofimportance for the theoretical understanding of the connec-tion between embryology, morphology and evolution.49

Franz saw his own contribution to the development ofthe theory of evolution foremost in his concept of ‘improve-ment’,50 but he also worked on the relationships betweenontogeny and phylogeny. Building upon the work of vonBaer, Fritz Mu ller and Haeckel, Franz tried to give agenetic and developmental explanation of the biogeneticlaw.51 If Plate can be seen as one of the major figures in thepre-Synthetic period, Franz is one of the major figureswithin the German language Evolutionary Synthesis. Heplayed an important role in Gerhard Heberer’s project, theedited volume Die Evolution der Organismen,52 which isarguably the most comprehensive statement of the Syn-thesis that was published during its formative phase inGermany.53

In his later works, Franz made explicit his true ambi-tions in elaborating and propagating the idea of a laddertowards perfection, which he attempted to convert into auniversal biological category. In his mature programmaticwork, Die Vervollkommnung in der lebenden Natur (Im-provement in Living Nature), Franz surveys the history ofthe idea of progress towards perfection (improvement)giving much attention to Kant and especially to Goethe’s‘doctrine of perfection’ (Vervollkommnungslehre).54 Heanalyses the concept of metamorphosis and claims that,although Goethe was more of an artist, with an outstand-ing intuition, than an actual scientist, and that he cannottherefore be counted among the forerunners of evolution-ary theory (here he departs from Haeckel), neverthelessGoethe proposed clear criteria of perfection: differentiationand centralisation.55 Darwin, according to Franz, playedan equivocal role in the story, since he inspired bothchampions and opponents of the theory of improvement.

Franz’s own concept of improvement mostly follows hisinterpretations of Goethe, although under consideration ofthe Darwinian concept of the struggle for existence, which hesaw as absolutely compatible with his idea of progress.56 Hedistinguishes a morphological concept of perfection (Goethe),centered on differentiation and centralization, which he callsan ‘ecological’ approach and traces back to Kant.

Goethe’s influence is central also to Franz’s ambitiousGeschichte der Organismen (The history of Organisms),

49 Franz V. Die Vervollkommnung in der lebenden Natur. Jena: Gustav FischerVerlag, 1920; Franz, V. Ontogenie und Phylogenie, Abhandlungen zur Theorie derorganischen Entwicklung III, 1–51, 1927; Franz, V. Die stammesgeschichtliche zuneh-mende Arbeitsersparnis beim Akkomodationsapparat des Wirbeltierauges. Ein Baus-tein zur Vervollkommnung der Organismen, Biologisches Zentralblatt 54, 403–418,1934; Franz, V. Der biologische Fortschritt. Die Theorie der organismengeschichtlichenVervollkommnung, Gustav Fischer, Jena, 1935.50 Ibid.51 Rehkampfer G. Zur fru hen Rezeption von Darwins Selektionstheorie und deren

Folgen fu r die vergleichende Morphologie heute. Sudhoffs Arch 81:171–192, 1997.52 Heberer, G. (ed.) Die Evolution der Organismen. Ergebnisse und Probleme der

Abstammungslehre. Jena: Gustav Fischer, 1943.53 Reif, W.-E.; Junker, T. and Hossfeld U. The synthetic theory of evolution: general

problems and the German contribution to the synthesis. Theory in Bioscience 119 (1):41–91, 2000.54 Franz V. Die Vervollkommnung in der lebenden Natur. Jena: Gustav Fischer

Verlag, 1920.55 Ibid, p. 36, 64.56 Ibid, p. 75.




https://www.researchgate.net/publication/286595616_The_synthetic_theory_of_evolution_General_problems_and_the_German_contribution_to_the_synthesis?el=1_x_8&enrichId=rgreq-e281d132-e1bf-4d55-a318-7e990197b237&enrichSource=Y292ZXJQYWdlOzI2ODIyMDgzODtBUzoxNjM4NDMyMDg2NTQ4NDhAMTQxNjA3NDY3MzEwNw==










63 Naef, A. Idealistische Morphologie und Phylogenetik. Jena: Gustav Fischer, 1919,p. 13.64 Naef, A.: Die individuelle Entwicklung organischer Formen als Urkunde ihrer

Stammesgeschichte. Jena: Fischer, 1917, p. 57.



where he applies Gothean morphology criteria to the mor-phological analysis of phylogenetic history.57 He claimsthat, despite the fact that Darwinian natural selection istheoretically far-reaching, it cannot solve the problem ofimprovement. There has been a long discussion, Franzargues, about whether Goethe’s Metamorphosis, skull re-search and other works influenced the way scientific stud-ies were conducted, but in relation to the concept ofimprovement, his importance was only now being fullyunderstood. Goethe’s concept of centralisation and differ-entiation is the basic idea of his entire volume Morphologie,which summarises Goethe’s botanical and zoologicalviews.58 The idea is clearly expressed in Goethe’s descrip-tion of the metamorphosis of insects and plants, as well asthe metamorphosis of the vertebra. Goethe was not aforerunner of Darwin, Franz continues, for he was stillfar away from the idea of phylogeny. However, if we wouldreplace his Urpflanze with simpler plants (such as a sea-weed or a fir tree) that appear to be the ancestors (Stamm-formen) of flowering plants, we would be able to discover aphylogenetic or evolutionary law (Entwicklungsgesetz) init.59 In other words, Franz claimed that Goethe’s morphol-ogy was in a certain sense ahead of Darwinian evolution-ism. The methodological problem that he tried to solve wasborrowing conceptual tools from Goetheanism to improvethe Darwinian research programme. Franz also empha-sised that his interpretation of progress in evolution is apart of the tradition going from Goethe via Haeckel tocontemporary issues (Goethe-Haeckelsche Vervollkomm-nungsgedanke).

Yet, not only Darwinian evolutionists appealed toGoethe’s heritage. The representatives of the structuralist(idealistic or typological) approach were under strongGoethean influence as well.60 Adolf Meyer-Abich (1893–1971), a contemporary of this structuralist renaissance,described its most important features.61 The cornerstoneof idealistic morphology (Meyer-Abich labelled it ‘idealisticbiology’) was the concept of the type. The type is an ideal orreal pattern (Muster) representing a certain class of phe-nomena and embodying the norm of this class. Idealisticmorphology is thus a ‘typological biology’ that is based on theidea of logical organisation of organic forms. These formsdevelop like crystals in accordance with their own laws andtheir ‘organs’ are primary in relation to their functions. Inother words, the primary objective of pure typology was tocreate classification systems for living organisms based onstructurally explicable characters without reference to phy-logenetic history or causal explanations. Typology, as a non-phylogenetic foundation of idealistic morphology, was con-ceptually neutral with respect to evolutionary mecha-nisms.62 The typologists all explicitly based their theories

57 Franz V. Geschichte der organismen. Jena: Gustav Fischer Ferlag, 1924.58 Ibid, p. 29.59 Ibid, p. 30.60 Levit G.S., Hossfeld U. A bridge-builder: Wolf-Ernst Reif’s historical studies and

the difficult fortune of Darwinism in German paleontology. Historical Biology,25(2):297–306, 2013.61 Meyer-Abich A. Das Wesen der idealistischen Biologie und ihre Beziehungen zur

modernen Biologie. Archiv fu r Geschichte der Mathematik, Naturwissenschaften undder Technik, 11: 149–178, 1928.62 Levit G.S., Meister K. The History of Essentialism vs. Ernst Mayr’s ‘‘Essentialism

Story’’: A Case Study of German Idealistic Morphology. Theory in Biosciences, 124(3–4): 281–307, 2006.



on the Goethean methodology and drew on his morphologi-cal works to a significant extent.

One of the characteristic examples is Adolf Naef. Naefwas one of the crucial figures in idealistic morphology but, atthe same time, he attempted to stay within the framework ofthe established empirical sciences and the pure typologicalmethod, without straying into metaphysical and religious-like generalisations in the manner of other influential ide-alistic morphologists such as Dacque and Troll. Naef’s pri-mary scientific focus was on molluscs. His early work dealtwith the biology of cephalopods. He saw it as his task tocreate a new ‘synthesis’, i.e. to revise the foundations ofmorphology within the context of a broad theoretical per-spective. His new morphology was to be built on the ‘soundfoundation of old idealistic morphology’.63 One of Naef’stheoretical objectives was the reformulation of Haeckel’sbiogenetic law in a way similar to that of Franz and AlexeiSewertzoff. Naef proposed the so-called ‘law of terminalmodifications’.64 Although the same basic assumption that‘phylogeny is due to modified ontogeny’ was shared by VictorFranz, Walter Garstang (1868–1949), Adam Sedgwick(1854–1913) and Gavin de Beer (1899–1972),65 Naef’s ver-sion of the relationship between phylogeny and ontogenywas incorporated into a different theoretical context.

The idealistic morphologists themselves called theirscience systematic morphology or comparative morpholo-gy.66 They used the typological method as the foundationfor their research programs.67 However, typology was onlyone element (although important) of their theoretical sys-tems, which could also include other elements, such ascreationism, phylogeny, mutationism, orthogenesis andneo-Lamarckism.

Idealistic morphology was not at all a methodologicalmonolith,68 but all idealistic morphologists subscribed tothe same initial idea, and Goethe played a crucial role inshaping their methodological presumptions: ‘With Goethe,the idealistic morphologists adopted holism and a concep-tion of organisms not as atomistic aggregates but as ganz-heitliche Gestalten’.69 Crucial was Goethe’s search for ageneral doctrine of form, for the idea of a certain structure,which escapes pure observation and simplistic explana-tions. This ‘idea’ can be expressed in different forms andcan be grasped indirectly by means of empirical studies.

But not only Darwinians and idealistic morphologiststraced their roots back to Goethe. Non-Darwinian evolu-tionists were also embracing the Goethean paradigm. Thebest known example is the anatomist Hans Boker

65 Sewertzoff A. N. 1949. Sobranije sotchinenij. V. 5. Moscow: Izd Akad Nauk [inRussian], pp. 389–397.66 Rieppel O. Wilhelm Troll (1897–1978): Idealistic morphology, physics, and phy-

logenetics, History and Philosophy of the Life Sciences, 33: 321–342, 2011; Rieppel O.‘‘Adolf Naef (1883–1949), systematic morphology and phylogenetics, Journal of Zoo-logical Systematics and Evolution Research, 50: 2–13, 2011.67 Rieppel O. Karl Beurlen (1901–1985), Nature Mysticism, and Aryan Paleontology.

Journal of the History of Biology. 45: 54–299, 2012.68 Rieppel O., Williams D.M., Ebach M.C. ‘‘Adolf Naef (1883–1949): On foundational

concepts and principles of systematic morphology’’, Journal of the History of Biology,46(3): 445–510, 2013.69 Rieppel O. ‘‘Wilhelm Troll (1897–1978): Idealistic morphology, physics, and phy-

logenetics’’, History and Philosophy of the Life Sciences, 33: 321–342, 2011.




75 Mayr, E. Thoughts on the Evolutionary Synthesis in Germany. In: Die Entstehungder Synthetischen Theorie: Beitrage zur Geschichte der Evolutionsbiologie inDeutschland (Junker, Th. and Engels, E.-M. (eds.). Berlin: VWB-Verlag, 1999, pp.19–30.76



(1866–1939) who combined neo-Lamarckism and holism inhis research programme. Boker himself claimed that hedeveloped his concept of ‘biological anatomy’ when writinghis Habilitationsschrift (2nd thesis) and initially employedit in his lectures in the 1920s. Boker tried to create a neo-Lamarckian evolutionary synthesis.70 He was aware ofselectionism but maintained that its explanatory poweris limited, even in the late 1930s. As he puts it: ‘if somebodynevertheless would claim that he could explain the originand transformation of species by means of mutation andselection alone, he must first wish to witness the richnessand complexity of anatomical and biological interconnec-tions and interdependencies going into the finest detail. Hewould then probably understand that biomorphologicalcorrelations cannot be explained only by appealing tothe separate ‘characters’ and ‘properties’ to which geneti-cists attach so much importance’.71

Boker called his central doctrine ‘comparative biologicalanatomy’72 and assumed that the organism is a ‘construc-tion’ confronting its environment. An organism remains inharmony with its environment until the environmentchanges. When it happens, there are two possibilities forthe organism: it will either perish or adapt to the newenvironment. An adaptation proceeds by means of anatomi-cal ‘re-constructions’ [Umkonstruktion] of the whole organ-ism and these re-constructions are heritable. It is importantto emphasise that, according to Boker, not all anatomicalstructures are ‘constructions’: ‘An organism consists of ana-tomical constructions and indifferent anatomical features;each anatomical construction is representative of a corre-sponding manifestation of life and environmental condi-tions’.73 Considering that ‘manifestations of life’ arecausally determined by their environment, ‘constructions’are adaptations and can be seen as relatively autonomousparts of the organism. Accordingly, ‘comparative biologicalanatomy’ is essentially a research programme comparingboth homologous and analogous ‘constructions’ of variousorganisms by considering their functional roles. For exam-ple, bats should be compared with all kinds of flying organ-isms. Doing so, one should reconstruct the completephylogenetic history of the organism by taking into accountecological, ethological, and morphological factors. At thesame time, reconstructing ‘constructions’ presupposes theuse of the typological method and makes Boker into a bridge-builder between evolutionists and idealistic morphologists.As might be expected, Boker was strongly influenced byGoethe, and wrote several works analysing his morphologi-cal heritage.74 Boker also made significant efforts to dem-onstrate that it was his own research programme thatcontinued the genuine Goethean tradition. He attributed

70 Boker, H. Begru ndung einer biologischen Morphologie. Zsch. Morph. u. Anthrop.24: 1–22, 1924.71 Boker H. Einfu hrung in die vergleichende biologische Anatomie der Wirbeltiere.

Jena. Bd. I 1935, Bd. II, 1937, p. IV.72 Hossfeld, U. ‘‘Konstruktion durch Umkonstruktion’’ – Hans Bokers vergleichende

biologische Anatomie der Wirbeltiere. Verh. zur Geschichte und Theorie der Biologie9: 149–169, 2002.73 Boker H. Einfu hrung in die vergleichende biologische Anatomie der Wirbeltiere.

Jena. Bd. I 1935, Bd. II, 1937, p. 8.74 Boker, H. Goethe und die Anatomie. Mu nchener Medizinische Wochenschrift, 79:

457–461, 1932.Boker H. Die anatomischen Sammlungen in Jena durch Goethe.Anatomischer Anzeiger 81: 293–302, 1936.Boker H. Goethes Beziehungen zur Ana-tomie und zum anatomischen Institut Jena. Leipzig: Wilhelm Engelmann, 1936.



to Goethe not only the doctrine of the type, but also theconcept of holistic ‘reconstructions’.

In summary, the figureheads of all morphological tradi-tions in Germany (Darwinian and Lamarckian evolution-ary morphology, developmental biology, idealisticmorphology) saw themselves as carriers of the Goetheantradition, and even tried to monopolise this tradition byshowing that they are the only ‘true Goetheans’. It isimportant to notice that Goethe wasn’t simply a ‘cultfigure’; all of the above morphologists adapted clearlydetectable concepts from Goethe. In other words, Darwini-an evolutionism developed within a specific conceptualframework, and these circumstances strongly influencednot only the first wave of the Darwinian revolution inGermany (Haeckel), but also its second wave (Rensch),to which we now turn.

Post-synthetic Darwinism: Bernhard RenschErnst Mayr (1904–2005) pointed out that the developmentof the Evolutionary Synthesis can be divided into twoperiods. The first period was initiated by the publicationof Genetics and the Origin of Species (1937) by the Russian-born American evolutionist Theodosius Dobzhansky(1880–1959). This period was ‘essentially completed in1947, as demonstrated by the Princeton conference andby Rensch’s book’.75 One can add that by this time (1947)the basic ideas of the Evolutionary Synthesis had propo-nents not only in the USA,76 the UK77 and Germany,78 butalso in the Soviet Union.79 Thus the revised version ofDarwinism was established simultaneously in three essen-tial language areas: English, German and Russian.

The second period in the development of the Synthesis,after 1947, Mayr labelled as ‘post-Synthesis’ to emphasizethat in this period Darwinians were in agreement aboutthe fundamental principles, the post-Synthetic develop-ments just specified, and had strengthened an alreadyexisting paradigm. Bernhard Rensch (1900–1990), withhis contribution to Heberer’s Evolution der Organismen80

and his mature theory of macroevolution, can be consid-ered as a crucial figure in both the Synthetic and the post-Synthetic periods in Germany.

Rensch was, arguably, one of the most controversialfigures on the international scene of the Synthetic move-ment. On the one hand, due to the efforts of Ernst Mayr andsome historians of science,81 Rensch became the figure-head of the German-language Synthesis. Mayr counted

Jepsen, G.L.; Mayr E. and Simpson, G.G. (eds.) Genetics, Paleontology, andEvolution. Princeton University Press, Princeton, N.J., 1949.77 Huxley, J. Evolution: the modern synthesis. Allen & Unwin, London, 1942.78 Heberer, G. (ed.) Die Evolution der Organismen. Ergebnisse und Probleme der

Abstammungslehre. Jena: Gustav Fischer, 1943; Rensch B. Neuere Probleme derAbstammungslehre. Die transspezifische Evolution. Stuttgart: Ferdinand Enke, 1947.79 Levit G.S., Hossfeld U., Olsson L. From the ‘‘Modern Synthesis’’ to Cybernetics:

Ivan Ivanovich Schmalhausen (1884–1963) and his Research Program for a Synthesisof Evolutionary and Developmental Biology, Journal of Experimental Zoology (MOLDEV EVOL) 306B: 89–106, 2006.80 Heberer, G. (ed.) Die Evolution der Organismen. Ergebnisse und Probleme der

Abstammungslehre. Jena: Gustav Fischer, 1943.81 E.g. Junker T. Die zweite Darwinsche Revolution. Geschichte des synthetischen

Darwinismus in Deutschland 1924 bis 1950 (Acta Biohistorica, Bd. 8). Basilisken-Presse, Marburg, 2004.






Rensch among the six ‘canonical’ architects of the ModernSynthesis (along with Huxley, Dobzhansky, Stebbins,Simpson, and Mayr himself).82 On the other hand, Renschcreated an exotic and sophisticated evolutionary meta-physics that seems, from a modern viewpoint, unrelatedto his sound evolutionary biology and hardly compatiblewith the worldviews of the other major figures in theSynthetic movement, such as Mayr’s philosophy of biology.Yet Rensch’s evolutionary biology is integral to his ‘philos-ophy’, which perfectly fits into the Goethean-Haeckelianline of thinking.

Rensch is first of all known as a biologist, who along withErwin Baur (1875–1933), Walter Zimmermann (1892–1980), Nikolai Timofeeff-Ressovsky (1900–1981) and Ger-hard Heberer and others contributed to the growth of theModern Synthesis in the German-speaking countries. Hismost well-known book in this respect is Neuere Problemeder Abstammungslehre – Die Transspezifische Evolution(1947), which became known in English under the titleEvolution above the Species Level.83 The rest of his scien-tific legacy is less known, with the exception of his histori-cal paper published in the seminal collective monographedited by Mayr & Provine,84 which shaped the mainstreamretrospective view of the history and borderlines of theSynthesis. Rensch was praised by Mayr as the only Ger-man co-architect of the Modern Synthesis. Following Mayrmany other English-speaking authors also reduce theSynthesis in the German lands to the contributions madeby Rensch.

Rensch himself retrospectively saw his scientific workas a part of a German and international interdisciplinarysynthetic lobby.85 His specific contribution to the Synthesiswas not restricted by the incorporation of systematics intothe general theory, but also involved the fields of paleon-tology and evolutionary morphology. Rensch’s writings onevolutionary biology between 1929 and 1947 demonstratean astonishing continuity of topics, methodology, and em-pirical generalizations, despite his shift from ‘old-Darwini-an’ to the Synthetic explanatory patterns in the late 1930s.

Rensch’s philosophy is an organic part of his theoreticalsystem. It is therefore insufficient to simply talk about the‘philosophy’ of a ‘scientist’. Rensch developed the ‘theoreti-cal’ part of his system as a framework and foundation forhis applied scientific methodology. Both parts developedtightly interconnected and interdependent.

In one of his latest works, the book Probleme generellerDeterminiertheit allen Geschehens (The Problems of thegeneral Determinacy of all Events) Rensch presented hispantheistic metaphysics as a holistic and scientificallybased world-view. This work is far from being the eccen-tricity of a retired scientist, but rather sums up methodo-logical reflections that began, according to Rensch himself,

82 Mayr E., Provine W.B. (eds.) The evolutionary synthesis: Perspectives on theunification of biology. Harvard University Press, Cambridge MA and London, 1980.83 Rensch B. Evolution above the species level. Columbia University Press, New

York, 1960.84 Mayr E., Provine W.B. (eds.) The evolutionary synthesis: Perspectives on the

unification of biology. Harvard University Press, Cambridge MA and London, 1980.85 Rensch B. Historical Development of the Present Synthetic Neo-Darwinism in

Germany.//Mayr and Provine, Hrsg, S. pp. 284–303, 1980, p. 298.86 Rensch B. Probleme genereller Determiniertheit allen Geschehens. Berlin; Ham-

burg: Parey, 1988, p. 11.



in 1939.86 We summarize his metaphysics as it is repre-sented in this culminating book, taking the earlier workssuch as his Biophilosophy87 into account.

Rensch assumes that ‘the only entirely reliable founda-tion for a philosophical world view is the indisputablereality [Wirklichkeit] of the phenomena [Tatsachen] ofconsciousness’, which normally appear as a ‘stream ofconsciousness’ and this is what should be analyzed froman evolutionary viewpoint.88 The very human ability toanalyze is an inherited feature acquired in the course ofevolution. The most essential trait of our ability to ‘drawconclusions’ can be explained by the adaptedness of thehuman mental apparatus to the regularities of the externalworld. This adaptedness to the lawfulness of the ‘extra-mental’ reality is the premise of the correlation betweenthe mental and extra-mental worlds.

Already on the first pages of this book Rensch makes acrucial point. In commenting on the difference between hisconcept and ‘evolutionary epistemology’, he is respondingto criticism by the evolutionary epistemologist GerhardVollmer, who claimed that Rensch‘s panpsychistic ident-ism is redundant if one considers Konrad Lorenz’ (1903–1989) concept of ‘fulguration’. In reply, Rensch arguedagainst all attempts to multiply reality, as was done byLorenz or Karl Popper (1902–1994), with his idea of tripleworlds. For Rensch, as we will see below, there is only onesingle, i.e. monistic, reality having, however, two funda-mentally different aspects: the mental and the material.

The basis of Rensch’s philosophy includes the negationof a-causal processes, i.e. in his view both the inorganicand the organic worlds are causally determined.89 Thusnatural selection is the major factor determining organis-mic evolution. Biological progress can be fully explained interms of Darwinian selectionism. Referring to Plate’sconcept of orthoselection, Rensch emphasizes that it issufficient for explaining orthogenetic series. Insofar evo-lution is a process determined in all its stages by funda-mental law-like principles, which control both thestructures’ development and their functions.90 For Renschmaterial, biological evolution is a determined and gradualprocess, although it involves stochastic events such asrandom mutations (whose randomness, however, stillwere conceived within an overall causal framework, asexplained below).

The evolution of the nervous system and of intellectualabilities is directed by natural selection as well, due to theadaptive advantages of more differentiated and specializedcells as compared to homogenous cell conglomerates.91

Going down the phylogenetic tree to lower vertebrates,one can experimentally show that they possess primitiveforms of mental abilities [Vorstellungen], for example, gen-eralizations. Even mollusks, Rensch argued, have primitivetaste-like sensations. The evolution of human cultures pro-ceeds mostly on the level of non-heritable characters,Rensch continues, and it is important to distinguish

87 Rensch B. Biophilosophy. New York [u.a.]: Columbia Univ. Press, 1971; Rensch B.Biophilosophie auf erkenntnistheoretischer Grundlage. Stuttgart: G. Fischer 1968.88 Rensch B. Biophilosophy. New York [u.a.]: Columbia Univ. Press, 1971.89 Ibid, pp. 15–16.90 Ibid, p. 23–24.91 Ibid, p. 30.




Figure 4. The philosopher and psychiatrist Theodor Ziehen (1862–1950) from Halle

University (The National Library of Medicine).

Figure 5. Theodor Ziehen communicated with both Haeckel and Rensch. Here

Ziehen’s letter to Haeckel (from the EHH Archive, Jena): ‘Jena, 2.12.[18]91. Sehr

geehrter Herr Professor! Da ich Sie in der vorletzten Sitzung des

naturwissenschaftlichen Vereins verfehlte und an der letzten selbst nicht

teilnehmen konnte, war ich bislang verhindert Ihnen meinen Dank fur die

freundliche Ubersendung ihrer Anthropogenie auszusprechen [. . .]. Mit

vorzuglicher Hochachtung. Ihr ergebenster Th. Ziehen’ (Dear Professor! Since I

missed you at the last but one meeting of the Society for Natural Sciences, and I

myself missed the most recent one, I had no possibility to express my gratitude to

you for sending me your Anthropogenie. With all due respect. Yours truly.

Th. Ziehen).



between psychic and neurophysiological phenomena.92 Forhuman consciousness, Rensch argues, the only ultimateobjects are its own psychic phenomena, resulting from theimmediate experiences: perceptions, imaginations, feelingsand thoughts. Only an analysis of these experiences makesit possible to develop concepts of extra-mental reality, whichappears to be a visible and testable formation [Gestalt].Thanks to physics we know that matter consists of atoms,elementary particles and waves. Finally, matter appears tobe ‘the ultimate something’, which will perhaps in the futurebe described only in terms of interactions of various forces,causal chains, and fundamental constants. Rensch appealsto the reductive realism of the German philosopher andpsychologist Theodor Ziehen (1862–1950), one of the mostcited authors in Rensch’s works, who posed the question ofthe suitability of ‘matter’ as a scientific term (Figs. 4 and 5).Ziehen is known as an author of psycho-physiological epis-temology93 based on monist assumptions. Rensch sharedthe philosophy of Ziehen and labelled it a ‘monistic princi-ple’.94 Ziehen was not a ‘Goethean’ in the same way asidealistic morphologists (who claimed to be his direct fol-lowers) and saw Goethe rather as a chain in a tradition goingback to Aristotle (384-322 B.C.E.).95 As any philosophicalmonism, the ‘monistic principle’ constitutes an ultimate,ontologically definable reality, which cannot be multipliedor decomposed into further elements, representing thevery foundation of the Universe, and providing it with the

92 Ibid, p. 34.93 E.g., Ziehen Th. Psychophysiologische Erkenntnistheorie. Jena: G. Fischer, 1898.94 Rensch B. Biophilosophy. New York [u.a.]: Columbia Univ. Press, 1971, pp. 29.95 Ziehen Th. Goethe’s Naturphilosophische Anschauungen. In: Walther J. (ed.)

Goethe’s Stellung zu den Problemen der Natur. Halle, Leipzig: Keiserlich Leopoldi-nische Deutsche Akademie der Naturfoscher, 1930.



elements of an individualized whole. In other words, mo-nism implies elements of holism. Rensch was looking for thistype of universal principle. It is important to emphasise thatthe rough draft of the contents of the book Evolution abovethe Species Level found in the Archives of the Academy ofSciences in Prague96 demonstrates that Rensch conceivedhis work from the very beginning as a deep theoreticalinvestigation with explicit methodological reflections. Zie-hen was Rensch’s main philosophical inspiration and it isnot a coincidence that in the first edition of the book Ziehen ismentioned more often than Darwin. As we know fromRensch’s diaries, the intensive reading of Ziehen’s episte-mological works immediately paved the way for writingEvolution above the Species Level.97

Rensch argued that the reduction of the basic mentalfeatures (sensations and imaginations) to their founda-tions will inevitably lead to the concept of ‘the ultimate

96 Levit G.S., Simunek M., Hossfeld U. (2008) Psychoontogeny and Psychophylo-geny: The Selectionist Turn of Bernhard Rensch (1900–1990) through the Prism ofPanpsychisticIdentism. Theory in Biosciences, 127:297–322, 2008.97 Ibid.




Figure 6. Bernhard Rensch and his wife Ilse in Endeh (13 July 1927) during their

Expedition to Lesser Sunda-Islands [preparation of the monitor lizard (Varanus

komodoensis Ouwens)] (Gerhard Heberer’s legacy, courtesy of Uwe Hossfeld).

This expedition stimulated Rensch not only to purely zoological insights, but also

ultimately to philosophical, anthropological, and culturological considerations.

103 Complete quote in German: ‘‘Gegeben ist uns nur Psychisches im Sinne desgewohnlichen Sprachgebrauchs, die sogenannten materiellen Dinge sind nicht gege-ben sondern werden erschlossen; see: Ziehen Th. Grundlagen der Naturphilosophie.Leipzig: von Quelle & Meyer, 1922, S. 2.104 Rensch B. Biophilosophie auf erkenntnistheoretischer Grundlage. Stuttgart: G.Fischer 1968; Rensch B. (1971) Biophilosophy. New York [u.a.]: Columbia Univ. Press,



something’; why not call this ‘something’ matter.98 It istherefore possible to advance a monistic view. A possiblecandidate could be a kind of spiritualism,99 for example theidealism of George Berkeley (1685–1783), Rensch main-tains. But the natural scientists would evidently havedifficulties with accepting Berkeley’s idealism. Alterna-tively, one can appeal to Benedict de Spinoza’s (1632–1677) concept of substance (1677), in order to avoid dual-ism. Spinoza postulated the basic and self-explanatorysubstance available for experience due to its attributes(substantia cogitans and substantia extensa). Along withSchelling and Hegel, who represented a similar position ‘toa certain extent’, Rensch also listed a couple of dozens ofmodern philosophers and scientists (e.g., Mario Bunge,Arthur S. Eddington, Ernst Haeckel, Bertrand Russel),who, in his view, developed the same or a similar method-ology.

Along these lines Rensch created his concept of psycho-physical identism.100 Already in the first edition of hismajor ‘synthetic’ publication, the Abstammungslehre (writ-ten in his Prague period) Rensch, in his own words, ‘pre-sented this worldview for the first time’. He was fully awarefrom the very beginning that his thinking is in line withSpinoza and Goethe.101 Commenting on the ‘psychic’ biasof his epistemology, Rensch stated: ‘We would like to pointout here once more that this world view is an idealistic one,since what is primarily given to us is the ‘psychic’; there isdefinitely no opposition between subject and object, matterand soul; even the abstract reductionist world [Reduktwelt]of natural scientists should not be searched for outside ofthe ‘conscious’ [Bewußten]’.102 Here Rensch reformulateswhat Ziehen labels as the basic idealistic principle [idea-listisches Grundprinzip] suggesting that ‘what is given is

98 Rensch B. Probleme genereller Determiniertheit allen Geschehens. Berlin; Ham-burg: Parey, 1988, S. 35.99 Rensch means (subjective) idealism in more ordinary terms.

100 Ibid, S. 36.101 Rensch B. Neuere Probleme der Abstammungslehre. Die transspezifische Evolu-tion. Stuttgart: Ferdinand Enke, 1947, S. 373.102 Ibid, S. 372.



only a psychic, in the habitual language use; the so-calledmaterial things are not given, but ought to be revealed’.103

In the Biophilosophie104 Rensch converted Ziehen’s ‘ide-alistic principle’ into the identistic foundation of his phi-losophy of biology, and coined the term ‘panpsychistic-identical or polynomistic world view’. Rensch formulatedtwo basic ‘facts’ constituting the basis of panpsychisticidentism: ‘1. The only reality of which we can be absolutelycertain relates to experienced phenomena, which includesensations, mental images, feelings, and volitional process-es as a whole. 2. Man does not consist of two separatecomponents – matter and mind, or body and soul, butrepresents an indivisible psychophysical unity’.105

In the voluminous book Das universale Weltbild [TheUniversal Worldview] originally published in 1977106 wefind Rensch’s most detailed and inclusive account of hisphilosophy of evolution. Like Ernst Mayr, Rensch main-tained that the laws of evolution differ in principle from thelaws of physics, because biological laws can have excep-tions. Thus he prefers to talk about the law-like character[Regelhaftigkeit] of evolution. Rensch lists about a hundredbasic law-like regularities in evolution, although eventhese one hundred rules do not exhaust the record. Belowwe extract some characteristic examples essential for un-derstanding Rensch’s position in relation to progress anddeterminacy in evolution.

The most universal evolutionary regularities inRensch’s list correspond to the standard set of rules ofthe Modern Synthesis, claiming that all plants and ani-mals undergo random mutations, while sexually propagat-ing organisms obey the laws of Mendel and all organismsproduce an excess of offspring. Natural selection controlsall developmental stages of all organisms, but acts also onand above the species level, therefore ultimately control-ling ontogeny and phylogeny. The new and advantageousstructures appear and evolve due to natural selection. Inthe case of weakly specialized forms (‘law of the unspecial-ized forms’) it leads to evolutionary progress (Hoherenent-wicklung).107 The steady and long-term selection undercertain environmental conditions causes orthogenetic se-ries (orthoselection, the term adapted by Rensch fromLudwig Plate). Thus all major evolutionary events andtransitions can be explained exclusively by means of natu-ral selection. The concept of the pre-phenomenal nature ofmatter plays no direct role in Rensch’s evolutionary expla-nations. Furthermore, even cultural evolution, Renschasserts, is directed by natural selection, the only differencebeing that genetically non-heritable features play themajor role. The most important part in the history of

1968.105 Rensch B. Biophilosophy. New York [u.a.]: Columbia Univ. Press, 1971, p. 299.106 Rensch B. Das universale Weltbild: Evolution und Naturphilosophie. Frankfurtam Main: Fischer Taschenbuch Verlag, 1977 (2. Auflage, durchges. und mit Anm.sowie einem Vorw. Von Franz Wuketits: 1991, Darmstadt: WBG).107 Rensch B. Das universale Weltbild: Evolution und Naturphilosophie. 2. Auflage,durchges. und mit Anm. sowie einem Vorw. Von Franz Wuketits: 1991, Darmstadt:WBG, S. 102.






civilization is assigned to science, which is driven byselection processes as well. The evolution of human cul-tures has been determined, first of all, ‘by the growingscientific knowledge108 bringing about new technologiesand social institutions’, whereas scientific knowledge itselfmakes progress due to the positive selection of concepts.109

So Rensch advocated an all-embracing evolutionism andselectionism and this research programme became explicitalready in his Evolution above the Species Level (Fig. 6).110

As Delisle puts it: ‘It has perhaps not been sufficientlyrealized, however, that the microevolution/macroevolutionequation in his conception only constitutes the intermediatelink of a gigantic and universal causal chain binding togeth-er all the cosmic entities, from microphysical phenomena allthe way up to the most complex life forms’.111 Naturalselection is the major source of lawfulness in evolution;although it differs from the lawfulness of physics, ‘it isnevertheless, possible to characterize evolutionary regular-ities [Regelhaftigkeiten] as laws [Gesetzlichkeiten]’.112 Con-sidering that natural selection continuously selects thebetter variants, evolution appears to be canalized into tightpathways, i.e. inevitably proceeds in certain directions.Thus, although elementary evolutionary events appear tobe random, evolution towards human intelligence and evo-lution of intelligence itself takes place along invisible rails.

Rensch’s view on the inevitability of evolution towardshuman-level intelligence is in sharp contrast to most otherleading Synthetic and ‘post-Synthetic’113 evolutionists (T.Dobzhansky, G. Simpson, F. Ayala, E. Mayr, J. Monod andmany others), which tend to claim that ‘there is no indica-tion in the geological record that the evolution of intelli-gence is at all inevitable’.114 Rensch, on the contrary,insists that the origin of humans from ape-like ancestors‘was presumably a lawfully determined [gesetzma ßigbedingter] process’.115 He does not reduce his concept of‘lawfulness’ to vulgar determinism and coins the notion of‘polynomic determination’. Polynomic determinationimplies that the whole range of biological, physical, chemi-cal, social and other natural laws control the entire processof evolution, intercrossing and interacting and bringingabout seemingly stochastic events, which, in fact, can beexplicated in terms of lawful processes. In other words,there is little chance in organic and cultural evolution, andlife would certainly occur on other planets with comparablechemical-physical conditions, and would evolve in a com-parable way to evolution here on Earth.116

108 Rensch’s italics.109 Rensch B. Probleme genereller Determiniertheit allen Geschehens. Berlin; Ham-burg: Parey, 1988, S. 116.110 Rensch B. Neuere Probleme der Abstammungslehre. Die transspezifische Evolu-tion. Stuttgart: Ferdinand Enke, 1947.111 Delisle R.G. The uncertain foundation of neo-Darwinism: metaphysical andepistemological pluralism in the evolutionary synthesis. Studies in History andPhilosophy of Biological and Biomedical Sciences 40, 2009, pp. 119–132.112 Rensch B. Das universale Weltbild: Evolution und Naturphilosophie. 2. Auflage,durchges. und mit Anm. sowie einem Vorw. Von Franz Wuketits: 1991, Darmstadt:WBG, S. 107.113 ‘‘Post-Synthesis’’ is, according to Ernst Mayr, a period after 1947.114 Barrow J.D., Tipler F.J. The Anthropic Cosmological Principle. Oxford, New York:Oxford University Press, 1986, p. 133.115 Rensch B. Das universale Weltbild: Evolution und Naturphilosophie. 2. Auflage,durchges. und mit Anm. sowie einem Vorw. Von Franz Wuketits: 1991, Darmstadt:WBG, S. 225.116 Ibid, S.108.



To sum up, we believe that Rensch’s general philosoph-ical background played a very important role for his all-embracing evolutionism. As becomes clearer in his latestworks, Rensch argued in favor of the gradual developmentof the entire world. For him there were no qualitativebarriers even between inert and living matter, animalsand humans. Both his universalist gradualism and ident-ism, along with the attempt to rescue some anthropocen-trism, are in line with the German naturphilosophicaltradition and can be seen as a further development ofHaeckel’s monistic aspirations.

ConclusionsErnst Mayr claimed that ‘virtually every author who hasattempted to apply Kuhn’s thesis to theory change inbiology has found that it is not applicable in his field’.117

Mayr listed the differences between Kuhnian paradigmshifts and scientific revolutions in the life sciences. First,Mayr found no clear-cut difference between science at thetime of revolutions and Kuhnian ‘normal science’. A seriesof microrevolutions can take place even in any of theperiods that Kuhn reserved for ‘puzzle solving’. In otherwords, there is no rigid distinction between revolutions andnormal science. Second, Kuhn makes no distinction be-tween theoretical shifts caused by new empirical discover-ies, such as the structure of DNA, and changes caused bynew conceptual developments. Third, ‘the introduction of anew paradigm by no means always results in the immedi-ate replacement of the old one’.118

The Darwinian revolution in Germany was the result ofa variety of influences and disciplinary convergences. Oneof the paths led from pre-Darwinian morphology via evo-lutionary morphology to the Modern Synthesis. Our re-search has confirmed Mayr’s claim that there was noimmediate replacement of one paradigm by another. Rath-er the development of novel conceptual structures lookedlike a Russian ‘matryoshka doll’ consisting of an over-arching ‘meta-paradigm’ embracing conceptual structuresof ever smaller scale. In our case studies, we demonstratedthat such a meta-paradigm for German morphology wasinitially established by Goethe. All subsequent methodo-logical frameworks evolved within this super-paradigm.Neo-Lamarckian and Darwinian evolutionary morpholo-gies, as well as structural morphology, developed theirspecific research programmes within the Goethean tradi-tion. Crucial figures of German Darwinism in all periods ofits history embraced this tradition. Ernst Haeckel, LudwigPlate, Victor Franz, and most notably Bernhard Renschnot only experienced ‘some influence’ from Goethe’s mor-phological ideas, but created their basic methodologiesalong the lines of Goethe’s theoretical foundations. A moststriking example of such a paradigmatic ‘matryoshka’ isthe path going from Goethe via Haeckel’s monism toRensch’s pantheism. Although Rensch adapted his panthe-istic metaphysics from Theodor Ziehen, its affinity withHaeckel’s monism is conceptually and historically uncon-troversial. Therefore, one can detect continuity in the devel-opment of German-language evolutionary worldview’s

117 Mayr E. What Makes Biology Unique? Cambridge, New York: Cambridge Uni-versity Press, 2004, p. 165.118 Ibid, p. 164.




https://www.researchgate.net/publication/24428002_The_uncertain_foundation_of_neo-Darwinism_metaphysical_and_epistemological_pluralism_in_the_evolutionary_synthesis?el=1_x_8&enrichId=rgreq-e281d132-e1bf-4d55-a318-7e990197b237&enrichSource=Y292ZXJQYWdlOzI2ODIyMDgzODtBUzoxNjM4NDMyMDg2NTQ4NDhAMTQxNjA3NDY3MzEwNw==





stretching all the way from pre-Darwinian to post-Synthesistimes.

One of the most striking problems, which occurs in thisrespect, is the nature of the Darwinian revolution as ameta-paradigmatic shift.

Ernst Mayr famously interpreted the ‘population vs.typological thinking’ controversy as a key issue in theentire history of both Western philosophy and naturalscience. He declared that typological thinking is basedon the essentialist philosophy, which can be traced backto Plato and Pythagorean geometry.119 The basic objectiveof essentialists was to discover this hidden nature ofthings. Essentialists dominated the intellectual landscapealso in the Middle Ages and well into the modern era.Nearly all philosophers until Darwin’s time, Mayr argued,were essentialists and ‘all of Darwin’s teachers and friendswere, more or less, essentialists’.120

According to Mayr, essentialism had direct and harmfulconsequences for biology, since species were considered tobe clearly discontinuous ‘natural kinds’ with constantcharacteristics (species fixism). It was Darwin, Mayrclaimed, who radically improved the situation by perceiv-ing the uniqueness of every individual in sexually reprodu-cing species. This view became a cornerstone of a new modeof thinking – population thinking – and laid the foundationfor the natural selection theory. Population thinking pro-ceeded from the assumption that biological reality consistsof uniquely different entities, while the statistical meanvalue is an abstraction121 (Mayr, 1982, pp. 46–47). In ourvocabulary, Mayr described the meta-paradigmatic shiftthat formed the foundation for the Darwinian revolution.

Now, there is a serious problem with Mayr’s account inthe light of our story. As a crucial figure in the German lifesciences, Goethe was a typologist and according to thereceived view must have been washed away by the streamof the Darwinian revolution. This, however, was not thecase. Instead, the specificity of German evolutionism per-sisted through the 2nd half of the 19th and into the 20th

119 Mayr, E. The Philosophical Foundations of Darwinism. Proceedings of the Ameri-can Philosophical Society. 145 (4): 488–495, 2001.120 Mayr, E. One Long Argument. Charles Darwin and the Modern EvolutionaryThought. Cambridge (Massachusetts): Harvard University Press, 1991, p. 41.121 Mayr, E. The Growth of Biological Thought. Cambridge & London: Belknap Press,1982, pp. 46–47.



century. Thus, Gegenbaur failed to make the methodologyof evolutionary morphology consistently evolutionary. Al-though the results of his research were presented in phy-logenetic terminology, the way he posed the problems wassignificantly typological.122 Haeckel’s Darwinism was ac-companied by a strong typological bias as well. BothGegenbaur and Haeckel, as well as their direct successors,failed to create a consistent Darwinian (in its original‘British’ version) evolutionary morphology. ‘Typologicalthinking’ survived in their concepts. As Di Gregorio sug-gested: ‘The old wolf had survived in sheep’s clothing’.123

At the times of the mature Modern Synthesis we findthat Rensch’s holistic theoretical system is in almost directopposition to Mayr’s philosophy, coinciding with it only onthe purely phenomenological level and in empirically test-able explanations. Indeed, beyond the elementary level, ofaccepting mutation, recombination, geographical isolation,and natural selection as the most important factors ofevolution, there is little that unites them, in light of thedeep philosophical differences between their systems.

Considering all this, we hypothesise that there are‘trading zones’ of a kind between theories and meta-para-digms. If Galison’s ‘trading zones’ were between ‘highchurch’ theories and ‘lower’ legions of applied scienceand engineering, our interpretation presupposes a mutualexchange between a theory and a meta-paradigm. As aresult, a theory undergoes serious transformations. Thispartly explains the specificity of the Darwinian revolu-tion(s) in Germany.

AcknowledgementsWe are thankful to Richard Delisle, University of Lethbridge, Canada, forinviting us to this Special Issue. Furthermore, we would like to thank IanG. Stewart, University of King’s College, Halifax, Canada, for valuableeditorial suggestions and encouragement. We would also thank AlexandrA. Lvov, ITMO University, St. Petersburg, Russia, for useful feedbackand proofreading the manuscript.Finally, we extend our thanks to the anonymous referees for a carefulreading of the manuscript.

122 Starck, D. Vergleichende Anatomie der Wirbeltiere von Gegenbaur bis heute.Verhandlungen der Deutschen Zoologischen Gesellschaft in Jena 1965: 51–67, 1965;Coleman, W. Morphology between Type Concept and Descent Theory. Journal of theHistory of Medicine 31: 149–175, 1976.123 Di Gregorio, M.A. A Wolf in Sheep’s Clothing: Carl Gegenbaur, Ernst Haeckel, theVertebral Theory of the Skull, and the Survival of Richard Owen. Journal of theHistory of Biology 28: 247–280, 1995.




https://www.researchgate.net/publication/22370723_Morphology_between_Type_Concept_and_Descent_Theory?el=1_x_8&enrichId=rgreq-e281d132-e1bf-4d55-a318-7e990197b237&enrichSource=Y292ZXJQYWdlOzI2ODIyMDgzODtBUzoxNjM4NDMyMDg2NTQ4NDhAMTQxNjA3NDY3MzEwNw==





The Darwinian revolution in Germany: from evolutionary morphology to the modern synthesis

Documents