Studies in History and Philosophy of Biological and Biomedical Sciences 44 (2013) 735–744

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Studies in History and Philosophy of Biological andBiomedical Sciences

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Ancestor of the new archetypal biology: Goethe’s dynamic typologyas a model for contemporary evolutionary developmental biology

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E-mail address: mriegner@prescott.edu

Mark F. RiegnerEnvironmental Studies Program, Prescott College, Prescott, AZ 86301, USA

a r t i c l e i n f o

Article history:Received 1 June 2012Received in revised form 17 May 2013Available online 18 July 2013

Keywords:ArchetypeEvo–devoGoetheMorphologyTheoretical morphospaceTypological thinking

a b s t r a c t

As understood historically, typological thinking has no place in evolutionary biology since its conceptualframework is viewed as incompatible with population thinking. In this article, I propose that what Idescribe as dynamic typological thinking has been confused with, and has been overshadowed by, a staticform of typological thinking. This conflation results from an inability to grasp dynamic typological think-ing due to the overlooked requirement to engage our cognitive activity in an unfamiliar way. Thus, ana-lytical thinking alone is unsuited to comprehend the nature of dynamic typological thinking. Over200 years ago, J. W. von Goethe, in his Metamorphosis of Plants (1790) and other writings, introduced adynamic form of typological thinking that has been traditionally misunderstood and misrepresented. Idescribe in detail Goethe’s phenomenological methodology and its contemporary value in understandingmorphological patterns in living organisms. Furthermore, contrary to the implications of static typolog-ical thinking, dynamic typological thinking is perfectly compatible with evolutionary dynamics and, ifrightly understood, can contribute significantly to the still emerging field of evolutionary developmentalbiology (evo–devo).

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Form is a moving, a becoming, a passing thing. The doctrine offorms is the doctrine of transformation. The doctrine of metamor-phosis is the key to all signs of nature.

J. W. von Goethe (quoted in Richards, 2002, p. 454)

1. Introduction

There are few concepts identified by evolutionary biologiststhat have received more criticism than typological thinking andessentialism. As Mayr (e.g., 1963, 1982, 1991, 1997) never tiredof pointing out (see also Chung, 2003), Darwin (1859) addressedthese notions and hoped to put them to rest by proposing that onlypopulations of variable individuals evolve, so-called populationthinking. Typological thinking was viewed as incompatible withthis evolutionary principle and thus had no place in evolutionarycausality (see Amundson, 2005 for in-depth critique of this posi-tion). Indeed, it has become anathema to even allude to typological

explanations in one’s research program, notwithstanding recentconceptual explorations in evolutionary developmental biologythat are more accommodating (e.g., Amundson, 1998, 2005; Hall,1996; Jenner, 2008; Lewens, 2009a).

In this paper I hope to show that, first, historically a static modeof typology has overshadowed a dynamic mode of typology. Conse-quently, a straw man has been erected and perennially attacked,but this caricature bears little semblance to the dynamic typologyproposed herein. Secondly, I will attempt to demonstrate how thedynamic typological thinking implicit in Goethe’s research ap-proach is perfectly compatible with a notion of evolutionarychange and, if rightly understood, not only stands as a forerunnerto modern evolutionary developmental biology (evo–devo) butalso speaks to current questions regarding the nature of evolution-ary dynamics. In fact, recent insights in evolutionary developmen-tal biology, including genetic regulatory networks, developmentalconstraints, analysis of theoretical morphospace, developmentaltrade-offs, and recursive properties of morphological evolution,

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reaffirm a notion of dynamic typology. However, to grasp dynamictypological thinking, it is necessary to engage our cognitive activityin an uncustomary way, and this is the very reason why this way ofseeing has been historically distorted: our practice of analyticalthinking falls short of what is necessary to apprehend the dynamicthinking implicit in Goethe’s way of understanding nature. Accord-ingly, I will explore in detail the subtleties of Goethe’s methodol-ogy to show how it is not just an historical curiosity but hascontemporary relevance for how we formulate questions regardingunderstanding morphological evolution. In this vein, I concur withRichards (2002, p. 408) ‘‘that Goethe’s understanding of scientificprocedure marked him not simply a good scientist for the time,but a good scientist for all time.’’

2. The dynamic nature of the archetype

Central to typological thinking is the notion of ‘‘archetype.’’Descriptions of archetypes and their relationship to physical enti-ties date back to Plato’s Republic and other writings. His oft-quotedallegory of the shadows on the cave wall, ultimately mistaken forthe full reality, identifies the relationship of, for example, actualorganisms and the informing ‘‘Ideas’’ that give them shape. Accord-ing to this interpretation, there exists an archetype, or eidos, of Cat,for instance, and all actual cats are but mere imperfect shadows, orapproximations, of this nonphysical entity. These archetypes havebeen taken to be ‘‘perfect,’’ whatever that may mean (it’s rarelydefined), constraining, and static, that is, unchanging andunchangeable. (Such interpretations, in fact, may stem frommisinterpretations of Plato. Bortoft (2012, p. 82), for example, citesH-G Gadamer, the Plato scholar: ‘‘Plato was no Platonist.’’) Accord-ingly, such notions cannot support organic transformation on anevolutionary timescale and lead to views of species fixism. If thearchetype is a nonphysical entity—not of this earth—how can itbe influenced by earthly processes? And if it exists in a state ofeternal perfection, how, and why, would it change? Why are livingorganisms so variable and thus only imperfect expressions of theirrespective presumed archetype?

To illustrate how this static interpretation has influenced biol-ogy, we need look no further than to the pre-Darwinian era, forexample to Richard Owen’s search for the archetypal vertebrate.Owen was determined to discover the ‘‘essence’’ of the vertebratebody plan, the unifying principle, or Unity of Type, common to allliving vertebrate forms (Amundson, 2005; Gould, 2002; Owen,2007[1849]; Richards, 1992, 2002; Rupke, 1993). Accordingly, hedistilled what he believed to be the key ingredients, the common

Fig. 1. Richard Owen’s ‘‘archetypal’’ vertebra

denominators, of vertebrate architecture and constructed a blue-print of basic, repeating skeletal features (Fig. 1). Owen, therefore,abstracted elements of the vertebrate body plan and juxtaposedthem in a generalized configuration; accordingly, his was a ‘‘reduc-tive theory’’ (Richards, 2002, p. 302). Clearly, Owen’s schemalooked like no actual vertebrate, living or extinct, although it hada vague resemblance to a fish skeleton. In 1859, with the publica-tion of Origin of Species, Darwin supplanted Owen’s hypotheticalarchetype with the presumed actual ancestral vertebrate—the ‘‘un-known progenitor’’—which gave rise to all subsequent vertebratesthrough descent with modification (Amundson, 1998; Brady,1987). Consequently, Owen’s influence was demoted, and alongwith him the Naturphilosophie movement of which he was a part,and apparently the problem of the vertebrate archetype, andarchetypes in general, was resolved.

Earlier, in 18th century Germany, however, a previous attemptwas made to ascertain the nature of the archetype, but this timenot only animals but geologic formations, meteorological phenom-ena, and especially plants provided the focus (Amrine, Zucker, &Wheeler, 1987). J. W. von Goethe’s (1749–1832) original researchon morphology—a term he coined (Nyhart, 1995)—sought to graspthe unity disclosed through the diversity of a given class of phe-nomena through ‘‘disciplined and cultivated perception’’ (Steiger-wald, 2002, p. 293). Regarding plants, after many years ofdetailed botanical observations, culminating in his celebrated Ital-ian journey, Goethe some years later claimed to have experiencedwhat he called the Urpflanze, the archetypal plant, the basic trans-formative element of which he termed ‘‘leaf’’ (Richards, 2002; Tan-tillo, 2002). Unlike Owen, Goethe did not attempt to express hisarchetype in a visual schema except for a few hastily scribbledlines he once showed to his philosopher friend Friedrich Schillerduring an animated conversation. Oddly enough, only subsequentself-proclaimed interpreters of Goethe have taken liberty to illus-trate his archetypal plant; as discussed below, these efforts were,and continue to be, based on a misguided notion of Goethe’sarchetype.

According to philosopher of science Brady (1987), after 1859Goethe’s notion of the archetype suffered the same ignominiousfate as Owen’s. But was this justified? A superficial analysis wouldnod in agreement, but, as Brady points out, this is based on a mis-reading of Goethe. In contrast to Owen’s abstract schema, Goethe’snotion of the archetype does not necessarily imply an ancestralform (nor does it deny one) and, more importantly, requires a dy-namic mode of cognition to be apprehended. Unlike a static blue-print that serves as a distilled generalization and representation

te (1848); reproduced in Owen (2007).

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of the phenomena under observation, Goethe’s archetypal Plant isa kind of fluid concept that unites the changing structures of theplant and enables the observer to see each structure not as sepa-rate but as multiple expressions of one ideal organ (Bortoft,2012). Thus, it is a dynamic property, a unifying principle withoutuniformity (Bortoft, 1996), that comes to expression through thedetails of the diverse, spatially separated form elements. In otherwords, it draws upon a dynamic typology, not the static typologythat has dominated Western thought through a likely misunder-standing of Platonism (Bortoft, 1996, 2012). An example fromgeometry may be helpful at this point.

From a Goethean perspective, the archetypal Triangle can neverbe represented or schematicized, but its essential, ideal principlesinform any number of triangles we may wish to construct. Clearly,while an infinite number of triangles can potentially be con-structed, no single triangle represents the archetype, but, rather,the essential attributes of the archetype are represented in everytriangle, otherwise the shape would not be a triangle but someother construct. Thus the archetypal Triangle is the idea that uni-fies—but does not generalize!—the diversity of shapes that are soconfigured by three lines and three angles. Any triangle that wemay draw would be a specific triangle but never the archetype,which exists only as a sort of unifying, or relational, idea that de-fines the limits and possibilities of all potential triangles and onlypartially comes to presence in any given triangle. How does Goe-the’s archetypal Plant fit with this notion?

Some visual examples may be helpful here. The Common Sow-thistle (Sonchus oleraceus) and Common Ragweed (Ambrosia artem-isiifolia), as in many plants, exhibit pronounced heterophylly, thatis, the leaf shape changes dramatically from the base of the stemto the apex. If the leaves are removed from the stem and arrangedin a linear sequence, one can readily notice the graded series oftransformation (Fig. 2). Goethe (1790) had a particular interest inthis phenomenon and maintained that in a given specimen thereis ‘‘one leaf’’ that undergoes ‘‘metamorphosis.’’ In other words,there exists a unifying idea that comes to expression in—or better,through—the numerous related shapes. This idea—which to Goethewas a cognitive experience grounded in sensory experience—is not

Fig. 2. Examples of leaf metamorphosis (heterophylly): (a) Common Sowthistle and (b)plant while those on the right are from the apex. (a) from leaf pressings made by autho

a static representation or an abstraction but a dynamic movement,a continuum, a living potential that belongs to the whole phenom-enon of the plant as much as do the individual organs. Again, this isnot to be confused with a ‘‘general plan common to all organs’’(Bortoft, 2012, p. 58). Rather, it is an expression of the plant’sbecoming, its temporal dimension. Accordingly, the leaves can beconceived as frozen moments in the development of the plant, vis-ible steps that enable the continuum to come to expression in anobserver’s consciousness. Although the continuum is not sensiblyperceived, it is, as Goethe maintained, a cognitive experience, forif the leaves are mixed randomly, a student, never having seenthe plant, is able to order them correctly with relative ease byweighing the differences against the similarities and thus ‘‘seeing’’the movement in his or her mind’s eye. Furthermore, if an earlyand later leaf of the sequence were removed and juxtaposed, theirrelatedness would be questionable (for example, the third leaffrom the left and last leaf of each sequence of Fig. 2). But, as differ-ent as the two leaves are morphologically, in the ‘‘context of move-ment’’ (Brady, 1998) their relatedness is immediatelycomprehensible.

The next step in apprehending the plant in its temporal devel-opment is to observe how the floral organs are further metamor-phic elements of the ‘‘leaf,’’ the ideal transformative impulse (andnot an actual leaf; see Richards, 2002, p. 396). In The Metamorphosisof Plants (1790), Goethe carefully describes the transition to calyx,petals, anthers, etc. as the plant continues its development beyondthe vegetative stage: ‘‘serial homology’’ in contemporary terminol-ogy. Compared to tracing the foliar metamorphosis, a further cog-nitive penetration of the phenomena is needed to identify theunifying thread that weaves though the floral parts. In some cases,however, the transition between foliar and floral organs is patentlyobvious as seen, for example, in the transition between leaf andbract in the neotropical heliconia (Fig. 3). In addition, after200 years, Goethe’s proposal has been acknowledged and corrobo-rated by genetic research that has identified how homeotic varia-tion in plants can induce the development of different floralorgans (e.g., Dornelas & Dornelas, 2005; Friedman, 2009; Smyth,2005; Theißen & Saedler, 2001; Weigel & Meyerowitz, 1994).

Common Ragweed. In each example, the leaves on the left are from the base of ther; (b) courtesy of C. Holdrege.

Fig. 3. Heliconia latispatha showing transition (‘‘metamorphosis’’) between leaf andbract.

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The previous observations need to be extended to yet anotherlevel. As becomes evident through a contemplation of Fig. 2, byengaging the cultivated imagination, one can quite readily andobjectively envision potential leaves within the gaps of the leaf se-quence; again, a student can easily sketch a potential leaf any-where in the sequence. It is quite a cognitive leap, however, tograsp the lawful nature of ‘‘plantness’’ so that one can pictoriallyenvision non-existent, yet conceivably possible, whole plants in asimilar way that one can invent undrawn triangles. This ap-proaches Goethe’s cognitive experience of the Urpflanze, or, inapproximate modern terminology, his experience of the theoreticalmorphospace of plants, the ‘‘occupiable’’ morphospace of Arthur(1997; for definition of theoretical morphospace, see McGhee,1999, 2007). In this regard, one must take Goethe’s words literally:

With this model and the key to it, it will be possible to go on for-ever inventing plants and know that their existence is logical;that is to say, if they do not actually exist, they could, for theyare not the shadow phantoms of vain imagination, but possessan inner necessity and truth. The same law will be applicable toall other living organisms. (quoted from Goethe’s Italian Journeyin Brady, 1987, p. 268)

Clearly, more is demanded of our cognitive abilities to reach theexperience of the archetypal Plant than is needed to cognize a miss-ing leaf in the sequence, but in each case it is the ability to appre-hend dynamically the precise boundaries and possibilities of anorganic integration that is prerequisite. In this sense, Goethe’s no-tion of the archetype anticipated Cuvier’s principle of the correla-tion of parts (presented in 1798), which also acknowledged theprinciple of organic integration. But because Cuvier’s organic visionwas grounded in a static typology, it failed to incorporate the pos-sibility for transmutation (Farber, 1976), that is, for evolution.

3. Between totipotentialism and constraint

The typological thinking implicit in Goethe’s dynamic concep-tion of the archetype is paradoxical. Regarding the leaf metamor-phosis example (Fig. 2), on the one hand there exists an infinitenumber of potential leaf shapes between any two actual leaves;this follows as a property of a continuum. In fact, every organism,through its ontogenetic trajectory, moves through a continuum ofinfinite forms. I will call this property totipotentialism (as distinctfrom the more narrowly defined concept of totipotency, which re-fers specifically to the fate of undifferentiated cells during morpho-genesis). On the other hand, the shapes of possible leaves arebounded and restricted, not just by the two actual bordering leavessurrounding each gap in the sequence but also by the unifiedmovement itself; not any random leaf will fit in the series. Thisis constraint. Thus the living organism exists somewhere in the dy-namic tension between totipotentialism and constraint, which canalso be thought of as the parameters of theoretical morphospace.Note that, contrary to the standard representation of typology

(e.g., Mayr, 1982; Sober, 1994), Goethe’s dynamic typological think-ing actually embraces the uniqueness of individual organisms or partsthereof, and thus the distinction between this form of typology andpopulation thinking begins to dissolve (see Levit & Meister, 2006).In fact, it is only through the identification and comparison of vari-ations on multiple levels of biological organization that Goethe’sdynamic archetype comes to presence through at least partial dis-closure. Evidently, striving to understand the ‘‘great malleability ofnature’’ is a central theme in Goethe’s scientific works (Tantillo,2002, p. 104).

But there’s more. According to Bortoft (2012), to enter morefully into Goethe’s way of seeing, one must understand what is im-plied by the act of distinguishing. ‘‘Distinguishing is a dual move-ment of thinking which goes in opposite directions at once: inone direction it differences [read as verb], whereas in the otherdirection it relates. So the act of distinction ‘differences/relates’—not differences and relates, because this would be two movements,whereas there is one movement which is dual’’ (p. 22). Further-more, our attention is usually drawn to what is distinguished andconsequently the act of distinguishing goes unnoticed, so we over-look the unity of phenomena and instead focus on the differencesand thus see only separation; this is characteristic of the analyticalmode of thinking. However, if we shift our awareness to the act ofdistinguishing, or the ‘‘coming-into-being of distinction’’ (p. 22),we begin to grasp Goethe’s way of seeing, which is characteristicof the holistic mode of thinking. This shift of awareness is criticalto understanding the dynamic typological thinking implicit in Goe-the’s phenomenology, but it is also an elusive and difficult cogni-tive activity to experience—and, to be fully grasped, it must beexperienced. What is necessary, as Bortoft (2012, p. 27) maintains,is a shift from thinking ‘‘downstream,’’ from what is already distin-guished, to ‘‘upstream,’’ to ‘‘the primary act of distinction.’’

Keeping in mind this notion of ‘‘coming-into-being,’’ we returnto a central theme in Goethe’s study of morphology: metamorpho-sis. In this sense, my earlier description of metamorphosis wassomewhat incomplete but necessary to draw attention to a featureof Goethe’s thinking that is typically overlooked: that is, the needto shift thinking from ‘‘downstream,’’ from what is finished, to ‘‘up-stream,’’ to what is nascent. This is expressed unambiguously byBortoft:

The metamorphosis is in the earlier embryonic stage of thecoming-into-being of the organs, and not in the later adult stageof organs that are already finished. Goethe’s way of thinking isintrinsically dynamic: it goes back ‘‘upstream’’ into the coming-into-being of the organs, instead of beginning ‘‘downstream’’with the organs that are already formed. Metamorphosis is onlyto be found in the coming-into-being, and the failure to realizethis leads us to look in the wrong direction by trying to under-stand metamorphosis in a downstream way. This is the sourceof much of the misunderstanding about Goethe’s work. (Bortoft,2012, p. 66)

In fact, Goethe’s own words point to this distinction between think-ing upstream, which here is implied by ‘‘reason,’’ and downstream,here implied by ‘‘practical understanding’’:

Reason is applied to what is developing, practical understand-ing to what is developed. The former does not ask, What isthe purpose? and the latter does not ask, What is the source?Reason takes pleasure in development; practical understandingtries to hold things fast so that it can use them. (quoted inMiller, 1995, p. 308)

This point, that development is central to Goethe’s view of nature, iswholly consistent with contemporary evo–devo’s platform thatontogenies, not adult stages, undergo evolutionary metamorphosis

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(Amundson, 1998) and that ‘‘[f]orm always has a developmentalorigin’’ (West-Eberhard, 2003, p. 201). Moreover, the formulationof a unified theory of evo–devo itself assumes ‘‘that developmentwill find a more inclusive place in the study of evolutionary biol-ogy . . .’’ (Hall & Olson, 2003, p. xv). And finally, the developmentalemphasis of dynamic typological thinking illuminates the historical,and somewhat contemporary, divide between Darwin—especiallythe neo-Darwinians—and the earlier embryologists and morpholo-gists, poignantly articulated by Amundson (2005): whereas themorphologists were concerned primarily with the explanation ofthe origin of form, Darwin’s goal was the explanation of change, withlittle interest in understanding how form arises. With the advent ofevo–devo, this schism is being bridged, and, if his contribution isunderstood correctly, it is incumbent upon us to include Goethein this dialogue.

4. The nested hierarchical structure of types, convergentevolution, and deep homology

The notion of the dynamic archetype described above is in needof still further elaboration. Returning to the earlier example of tri-angles, one can slightly reduce the specificity that unites the ob-jects to now embrace the category ‘‘polygon.’’ Consequently,triangles are now joined by rectangles, trapezoids, hexagons, etc.into a relatively broader, more inclusive class of geometric con-structs. Accordingly, the category of triangle becomes nested intoa less specific category, that is, the category of polygon. In contrast,we could make the triangle category more specified by adding therequirement of possessing a right angle; consequently, inclusionwould be restricted to only right triangles of which there still existsa potentially infinite number.

For a biological example, consider cats (family Felidae). If wewere to emulate Goethe’s cognitive experience, but this time direc-ted toward grasping the ‘‘archetypal Cat’’ in the mind’s eye, aftercareful empirical study we would be able to recognize in each ofthe 37 living species of felids the lawful integration of organic fea-tures that constitute the expression of the dynamic type in eachspecies’ configuration. As disparate as are a tiger, a mountain lion,and an ocelot, for example, they are but variations on a theme, theOne form expressed in the many (Bortoft, 1996), or the One formcoming-into-being as ‘‘self-differencing’’ (Bortoft, 2012), just asare the leaves along the stem of an annual plant (Fig. 2). But thefamily Felidae is nested within a higher recognized category, thatof the order Carnivora, which itself is nested within the class Mam-malia, and so on. (As with right triangles mentioned above, wecould also consider a more restrictive category, such as the genusPanthera, for example.) Thus, archetypes, in a Goethean sense, areconstrued as nested hierarchical identities, or as subtypes nestedwithin types, and it’s the observer’s intentional focus that circum-scribes the taxonomic level under investigation. The structure ofGoethe’s dynamic type, therefore, meshes seamlessly with the no-tion of a hierarchical structure of animal (and plant) body planscentral to evo–devo: ‘‘A hierarchical or nested view of Bau-pläne . . . is . . .both appropriate and essential for any investigationinto the origin of body plans and the systematic organization andevolution of structures and organisms’’ (Hall, 1996, p. 226).

But there is yet another level of complexity and interrelated-ness, the expression of which is observed in so-called convergentevolution. Traditionally, convergence is understood to result whentwo unrelated lineages evolve similar adaptations independently inresponse to similar selection regimes, for example similar environ-ments. This scenario presupposes that the same randomly gener-ated variations must be present coincidentally in each of the twoindependent and isolated lineages in order for natural selectionto operate congruently, an assumption that has rarely been vali-

dated or even tested. Can such an improbable scenario be the cau-sal factor behind the striking similarity between, for example, NewWorld hummingbirds and Old World sunbirds, placental mammalsand Australian marsupials, the black-and-white color pattern ofgiant pandas, indri lemurs, and orcas, or the stem-succulent mor-photype of cacti and euphorbs? From the perspective of dynamictypological thinking—where no morphotype exists in isolation—these similarities are not problematic in that just as types andsubtypes are in a sense nested hierarchically, so too can their qual-itative features be construed to intergrade horizontally, that is,across diverse phylogenetically unrelated taxa (note that the limi-tations of language constrain such descriptions to physical terms).Thus, the black-and-white pattern of the aforementioned mam-mals has most likely not arisen randomly in each respectivelineage but is an expression of a pattern-generating mechanismshared among otherwise diverse species. For example, Mundyet al. (2004) identified a shared genetic mechanism that underliesa similar plumage pattern found in distantly related birds (e.g.,Snow Geese and Arctic Skuas), while Riegner (2008), in a broadstudy across the entire class of birds (Aves), found repeating plum-age-pattern elements (e.g., streaks and bars), intercorrelated withother features, distributed with regularity and predictability acrossa wide array of unrelated species (discussed below). And theseshared color-pattern motifs need not be limited to members ofthe same vertebrate class. For example, just as complex patternsof spots and stripes are typical in species of wild cats (e.g., tiger,jaguar, and ocelot), which are carnivorous, so too are they commonamong birds of prey (e.g., hawks, falcons, and owls), which also arecarnivorous. Thus, the expression of these similar pattern elementsin unrelated taxa may, in fact, stem from a homologous pattern-generating mechanism. Standard homology, however, is insuffi-cient to explain these shared patterns among very distantly relatedtaxa but must be extended to a deeper hierarchical level of homol-ogy, that of ‘‘deep’’ homology (Wake, 2003) or ‘‘underlying’’ homol-ogy (Rutishauser & Moline, 2005). Of the many remarkablediscoveries of evo–devo in the past few decades, perhaps the mostsurprising has been the uncovering of shared developmental path-ways between vastly different organisms separated by millions ofyears of evolution. For example, the formation of eyes in flies andvertebrates is attributed to a shared developmental pathway(Carroll, 2005), as is pelvic bone reduction in both stickleback fishand manatees (Shapiro, Bell, & Kingsley, 2006), while a stunningrecent discovery has demonstrated deep homology of the arthro-pod central complex (i.e., nervous system) and vertebrate basalganglia (Strausfeld & Hirth, 2013). Again, from a Goethean typolog-ical perspective, these discoveries of profound relatedness amongmarkedly diverse animals are consistent with the notion of theOne ideal organism—at the most inclusive hierarchical level of theanimal archetype—self-differencing into the multifarious speciesthat populate the earth.

5. Archetypes and patterns in morphospace

The foundation of a Goethean study of any class of phenomenarequires painstakingly detailed observations followed by morpho-logical comparisons and the consequent identification of patternsof interrelationships. Undoubtedly the most extensive applicationof a Goethean approach to any class of phenomena is that of evo-lutionary morphologist Wolfgang Schad who has demonstratedwhat can be gained by applying a Goethean-derived dynamictypology to the class of mammals (Schad, 1977, 2012; see alsoRiegner, 1998). Schad’s approach has inspired recent research ona number of taxa, including rather unusual groups such as dino-saurs (Lockley, 2008) and early vertebrates (Kümmell, 2011). Here,taking some cues from Schad’s work, and drawing on a broad study

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of avian morphology (Riegner, 2008), I briefly outline how one mayaddress the question: What is the archetype—or, in other words,the parameters of theoretical morphospace—of birds?

Clearly, the world of birds presents a dizzying array of color pat-terns, sizes, morphologies, ecologies, behaviors, etc. Approachedfrom a Goethean perspective, one must entertain the notion thateach detail holds significance and that all are intercorrelated onvarious levels (i.e., nested hierarchies) of biological organization.In order to establish a context for defining the archetype—i.e., the-oretical morphospace—of birds, it is instructive to begin by com-paring morphologically widely divergent taxa. Besides occupyingthe opposite extremes of body size in avian morphospace, ostrichesand hummingbirds in many respects are morphological opposites.For example, whereas the head is relatively small and the neck dis-proportionately long in the ostrich, the opposite is the case in thehummingbird (Table 1). A comparison of these avian morphotypeshighlights Goethe’s principle of compensation or, in contemporaryterminology, developmental trade-offs, both within and betweenorganisms, as noted in his observation that ‘‘the neck and extrem-ities are favored in the giraffe at the expense of the body, but thereverse is the case in the mole’’ (quoted in Miller, 1995, p. 121).In other words, an organism cannot be the best of all possibleworlds: an exaggeration in one feature can arise only because an-other is de-emphasized. For example, the loss of hind limbs inwhales has presumably permitted the remarkable over-develop-ment and lengthening of the jaws (which, in a sense, are the‘‘limbs’’ of the head). In contrast, the huge hypermorphic hindlimbs of T. rex were only permissible due to the stunted, vestigialforelimbs of this Cretaceous dinosaur (a similar morphological pat-tern is seen in the modern-day kangaroo mice and rats, family Het-eromyidae). On a physiological level, a comparison of relative brainsize and gut length in howler monkeys—which eat mainly difficult-to-digest but easily accessed leaves—and in spider monkeys—which eat easy-to-digest but more difficult to acquire fruits—indi-cates that the former has a relatively smaller brain but larger gutthan the latter (Allman, 2000). Emlen (2000) has identified a devel-opmental trade-off (i.e., an inverse relationship) between thelength of ‘‘horns’’ and the size of compound eyes in Onthophagusdung beetles, and many more examples have been documentedin other animals as well as in plants (see, for example, West-Eber-hard, 2003, especially chap. 16). Accordingly, by considering Goe-the’s principle of compensation, the limits and possibilities ofpotential morphologies can be grasped objectively through carefulstudy of any class of biological phenomena. These considerations,in turn, point to complex patterns of compensatory developmentaltrajectories or, in other words, dissociated heterochronies (McNa-mara, 1997), a discussion of which would fall outside the scopeof this article.

In order to continue articulating an outline of the theoreticalmorphospace of birds, it is necessary to examine various character-istics and search for correlated trajectories; in other words, it needsto be derived empirically. For example, Riegner (2008) consideredplumage pattern, body size, morphological accentuation (i.e., ante-rior—posterior), and developmental mode (i.e., altricial—precocial)across a wide array of birds. When these features are considered

Table 1Morphological comparisons between ostrich and hummingbird.

Relative sizes Ostrich Hummingbird

Head: body size Small LargeBill: head size Short LongNeck: trunk length Long ShortTrunk: body length Short LongWing: body length Short LongLeg: body length Long ShortFoot: leg length Short Long

together, correlations become evident, which can be integratedinto a conceptual model (Fig. 4). Thus, small birds (e.g., passerines,such as warblers, sparrows) tend to have a countershaded orstreaked (i.e., longitudinally striped) plumage, a long tail, and arehatched in an altricial condition. Larger birds (e.g., nonpasserines,such as ostrich, geese, pheasants), in contrast, tend to have a uni-formly colored plumage or have bold color patches and/or bars(i.e., transverse stripes), a relatively shorter tail and accentuatedanterior (e.g., long neck and/or casque, wattles, dewlap), and areoften hatched in a precocial condition. Intermediate-sized birds(e.g., birds of prey) often display complex pattern of streaks, spots,or bars (Riegner, 2008). Moreover, the plumage-pattern trajectoryis recursive, that is, pattern elements recur in modified configura-tions in distantly related species across the diversity of birds (fordiscussion of recursion, see Bird, 2003). For example, the CommonRaven (Corvus corax) is in the passerine taxon but clearly notcountershaded or streaked but uniformly dark as is typical for largespecies. However, this species is among the largest of passerines, soin that taxonomic context the recurrence of uniform coloration isconsistent with the overall pattern. Similarly, plovers are generallysmall-bodied birds, but within this taxon the smallest species (e.g.,genus Charadrius, Ringed and Semipalmated Plovers) are typicallycountershaded, occasionally with broken bands below, while thelarger species (e.g., genus Pluvialis, European and American Gold-en-Plovers) exhibit solid black undersides in the breeding plumage,that is, reverse countershading in relatively robust birds, whichagain is a recurrent plumage pattern typical of the largest of birdswithin a given taxonomic context (see Fig. 4).

Clearly, the model depicted in Fig. 4 does not define the com-plete multidimensional theoretical morphospace of birds, and itcertainly does not represent an archetype in the Goethean sense

Fig. 4. Approximation of avian morphospace. The trajectory of plumage patterns iscorrelated with various morphological features and is recursive at finer levels oftaxonomic comparison. Plumage patterns are, from left to right: countershaded;streaked; spotted, drab, or blended; barred; bold separation of black and white oruniform dark; and reverse countershaded. Figure reproduced from Riegner (2008)and used with permission.

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(which, recall, can never be visually represented), but it doesidentify the dynamic interrelationships of selected features thatare grounded in empirical observation and, taken together, cansubsequently serve as a conceptual guide to make sense of other-wise diverse, and mistakenly random, phenomena. Moreover,based on just a few given characteristics, the model can be usedto predict what a possible species may look like or, at the veryleast, what forms are not permissible in avian morphospace, suchas an adult duck the size of a finch or vice versa. And finally, it isnotable that the color pattern—body size relationship seen in birdsis also apparent in other animal groups, such as mammals. Forexample, small mammals (e.g., rodents, such as deer mice) tendto be countershaded, large species (e.g., hoofed mammals, suchas bison) are often uniformly colored, and intermediate-sizedmammals (e.g., carnivores, especially cats) display complex pat-terns of spots and/or stripes (Riegner, 1998; Schad, 1977, 2012).Furthermore, when rodents have stripes they are aligned horizon-tally (e.g., thirteen-lined ground squirrel), and when hoofed mam-mals have stripes they are aligned vertically (e.g., zebras). Amongcats, in smaller species (e.g., ocelot) the striping pattern is horizon-tal (as in rodents), while in larger species (e.g., tiger) the stripes arevertical (as in hoofed mammals); intermediate-sized cats (e.g.,leopard) display a spotted pattern that is neither longitudinallynor transversely orientated. Thus, while Lewens (2012) arguesagainst the reliance on essentialism to explain the ‘‘stripyness’’ oftigers, from a Goethean perspective the more interesting, andrevealing, questions are: why do tigers specifically have verticalstripes, or why do mountain lions altogether lack stripes? Thesequestions can be addressed when one grasps the dynamic natureof the mammalian type and associated subtypes (Riegner, 1998;Schad 1977, 2012).

6. Theoretical morphospace and recursion

Whether one observes the changing leaf shapes in a gradedseries, the morphological variations among wild cat species, orthe different kinds of teeth in the mammalian jaw, dynamic typo-logical thinking shows that each grouping discloses a single idealform in multiple guises, that is, ‘‘multiplicity in unity’’ (the epis-temological inversion of ‘‘unity in multiplicity;’’ see Bortoft,1996). From a traditional perspective, this is the notion of homol-ogy, including serial or ‘‘iterative’’ homology (Roth, 1991). Dy-namic typological thinking, however, reaches further in that thevariation among these manifestations is not considered randomor accidental but obeys a strict, inherent lawfulness. The effortto discover these ‘‘inherent laws of form’’ is what lies at the heartof Goethe’s science of morphology and his notion of the dynamicarchetype.

If practiced diligently, dynamic typological thinking can answerthe call to develop a theoretical morphology in which ‘‘[t]he ulti-mate triumph. . .would be an understanding of biological diversity,framed in terms of the boundaries between the possible and theimpossible. It should integrate across all levels of structure, fromorganic molecules to entire and seemingly complex functioningorganisms, where as yet undiscovered laws of structural conso-nance may exist’’ (Hickman, 1993, p. 170). In other words, ques-tions can be addressed that seek to understand ‘‘the significanceof the spatial distribution and density of forms within morpho-space’’ (McGhee, 2001, p. 172) based on the distribution of obser-vable morphotypes (Gould, 2002) or ‘‘occupied’’ morphospace(Arthur, 1997). As discussed earlier, Goethe’s Urpflanze can be con-strued as defining the theoretical morphospace of plants, not as anabstraction but as an objective cognitive experience. Thus, if rightlyunderstood, the thinking implicit in Goethe’s notion of the arche-type can be applied to any class of biological phenomena to invite

a more thorough apprehension of the organizing principle, the dy-namic activity that unites the disparate parts.

The varying but related forms of, for example, sequential leavesup a stem or vertebrae along a spinal column, or the set of primaryfeathers of a bird’s wing, display recursive properties in that themorphological elements reiterate in modified configurations bothwithin a given organism and between species. Indeed, the evolu-tionary process itself seems to be recursive, generating fractal-likevariation, a characteristic of well-ordered chaotic systems (Bird,2003). Apparently, even our thinking activity exhibits recursiveproperties (Corballis, 2007). In addition, gene regulatory networksare described not only as structured hierarchically (Erwin & David-son, 2009; Schoch, 2010) but as highly recursive (Davidson & Er-win, 2006). Accordingly, the principles and applications of chaostheory and fractal geometry (e.g., Barnsley, 2006) evidently inter-sect those of dynamic typology, and there is presumably much tolearn here. Dynamic typological thinking, in fact, is well suited totrace the unifying thread that weaves through the fractal variationencountered among natural phenomena.

Chaotic, fractal, and recursive properties are evident not onlyamong serially homologous structures within an organism (e.g.,leaf sequence) or in comparisons of morphological elementsamong unrelated organisms (e.g., avian plumage-pattern ele-ments) but also by noting variations in phenotypic expression ofa given organism under varying environmental contexts. This latterphenomenon is addressed by epigenetics (Jablonka & Lamb, 2005)and, more specifically, by phenotypic plasticity (Pigliucci & Pres-ton, 2004). Yet again, over 200 years ago Goethe’s astute observa-tions described these phenomena: ‘‘. . .a plant growing in low-lying, damp spots will . . .develop smoother and less refined leavesthan it will when transplanted to higher areas, where it will pro-duce rough, hairy, more finely detailed leaves’’ (Goethe, 1790, p.19). These observations revisit the notion of the dynamic relation-ship between totipotentialism and constraint. For example, it isclear that, when an acorn germinates, an oak—and nothing else—will subsequently grow; that is constraint. But the particular forma given oak takes, from a potentially infinite number of possibili-ties, will depend on how the environmental conditions—soil chem-istry, slope, sun exposure, wind, snow loading, animal damage,etc.—influence the expression of the genotype, the outcome ofwhich cannot be precisely predicted. Similarly, we know that a ti-ger will have stripes, but the exact distribution of those stripesacross the tiger’s body, like our fingerprints, is indeterminate, mostlikely due to immeasurable developmental perturbations of initialconditions.

7. Is the idea of the archetype a mental abstraction, an actualorganizing principle, or neither?

Adhering to Goethe’s experience of dynamic typological think-ing as described above, it is a worthwhile exercise to ask whetherthe archetype, as so construed, is merely a mental abstractionadded to the phenomena, or whether it has any claim to realitydrawn out of the phenomena independent of a human mind toapprehend its characteristics. In other words, is it an organizingprinciple that plays a role in morphogenesis, development, andeven organic evolution?

This, evidently, is an ontological question, which I will not pre-sume to answer except by exploring what I think would haveapproximated Goethe’s interpretation. First, recalling the leafmetamorphosis example above (Fig. 2), what exists between thesensibly perceived elements—that is, between the leaves—whatmoves between them, is as crucial to Goethean phenomenologyas the elements themselves. In other words, the complete plantphenomenon includes not only all the morphological structures

742 M.F. Riegner / Studies in History and Philosophy of Biological and Biomedical Sciences 44 (2013) 735–744

but also the dynamic movement—that is, the set of objective, rela-tional ideas—which links together each of the separate parts (notethat the parts only appear as separate in a spatial dimension).Furthermore, as I hope to have demonstrated, the dynamic move-ment of the developing plant, its coming-into-presence, is notmerely a subjective mental representation, nor an abstract gener-alization, but an objective cognitive experience based on the tangi-ble existence of the actual leaves and floral morphology. Weapprehend the dynamic Idea of the plant by delving into the detailsof its parts and thereby accessing the intensive dimension of thephenomenon (Bortoft, 1996, 1998). Accordingly, Goethe may haveproposed that this dynamic cognitive activity is in resonance withthe transformative principle itself, which shapes the developingorganism and ‘‘moves it’’ through its various ontogenetic stages.As Bortoft (1996, pp. 240–241) explains, ‘‘The organizing principleof the phenomenon itself, which is its intrinsic necessity, comesinto expression in the activity of thinking when this consists in try-ing to think the phenomenon concretely. What is experienced isnot a representation of the organizing principle, a copy of it ‘inthe mind,’ but the organizing principle itself acting in thinking.’’

In this regard, Goethe (1790) referred to ‘‘sap’’ as becomingmore purified as it rises through the plant, and the image of thisis observed in the sequential refinement of the leaves and then flo-ral parts traced up the stem. But here again, as in his designation of‘‘leaf’’ as the unifying principle behind metamorphosis, ‘‘sap’’ mayhave been his expression for the dynamic biological activity thatcontinually shapes and reshapes matter in a living organism. Thisis not a vitalistic notion, as some have mistakenly asserted, butpoints to an organizing principle, which to this day remains elusivebut central to the biological sciences. What, for example, drives theprocesses of growth and differentiation in the embryo? Why is theeight-cell stage of development not ‘‘content’’ to remain as suchbut continues dividing, growing, and differentiating? These ques-tions reside at the frontier of our understanding of morphogenesis,and, I maintain, is what Goethe’s dynamic typology attempts toexplore.

8. Is dynamic typological thinking compatible with traditionalprinciples of evolution?

Regarding descent with modification, although Goethe’s arche-type does not necessarily imply ancestral forms, it does not ex-clude them. After all, there’s no reason why a temporal series offossil forms cannot be arranged sequentially just as individual leafshapes in the graded series and, through interpolation, lend them-selves to a determination of what the missing—i.e., potential—forms may have been. Indeed, chapter nine of D’Arcy Thompson’sclassic text, On Growth and Form (1961), demonstrates how thisis undertaken through mathematical applications, which, however,should not be confused with engaging the faculty of dynamic cog-nition described here. Thompson’s analytical methods remainexternal to the phenomena whereas a cognitive apprehension ofthe type internalizes the phenomena; superficially, the resultsmay appear similar or even identical, but the two procedures havedifferent implications for our understanding of evolutionarydynamics.

Additionally, dynamic typological thinking does not reject thecentral tenets of neo-Darwinism, that is, random mutation andnatural selection. However, while the premise of non-directionalvariation is only weakly supported by the view expressed here,natural selection remains intact, though shifted to a level of sec-ondary importance. In other words, ‘‘the variation presented toselection is nonrandom’’ (Raff, 1996, p. 428) and thus results in‘‘developmental bias’’ (Arthur, 2004), which would ultimately ‘‘biasa lineage’s access to morphospace’’ (Sterelny, 2000, p. S385). Con-sequently, natural selection should be considered not creative but

only eliminative. Thus, dynamic typological thinking (and evo–devo) does not deny random mutation and natural selection butdoes not view organic evolution as fully, or even satisfactorily, ex-plained by these mechanisms.

The evidence for gene regulatory networks lends further sup-port to Goethe’s notion of the dynamic archetype. In fact, the par-allels between the two are remarkable. As seen in the earlierexample of the leaf sequence (Fig. 2) in which the intervals be-tween the leaves are crucial, it has become apparent that, althoughthe genes themselves influence a given phenotype, it is the net-work of interactions between the genes, the relationships betweenand among them, that ultimately translates into the phenotype(Davidson & Erwin, 2006). This discovery moves well beyond plei-otropy and epistasis, and is clearly a paradigm shift that is begin-ning to alter the way we understand gene expression and theorigin of biological form. Whether this shift in understanding willultimately lean closer to the ideas discussed here is an openquestion.

And finally, it is notable that recent publications by philoso-phers of science have revisited typology and essentialism and havenot only identified flaws within the ‘‘essentialism story’’ (Amund-son, 2005; Winsor, 2006) or the ‘‘received view’’ (Wilkins, 2009)promulgated by a generation of evolutionary biologists, but alsohave proposed convincing arguments for reconsidering and even‘‘resurrecting’’ at least some form of biological essentialism (e.g.,Devitt, 2008; Lewens, 2009b; Love, 2009; Okasha, 2002; Walsh,2006; Wilkins, 2010). Note, however, that these proposals admit-tedly differ somewhat from those made in this paper and that noneconsiders the dynamic typology implicit in Goethe’s way of under-standing nature.

9. Setting the record straight

Historically, uncritical thinking has amalgamated what I havecalled static and dynamic typological thinking. Consequently, Goe-the, and most likely others (even Plato; see Bortoft, 2012), was mis-takenly accused of promoting a world view that has no place inmodern evolutionary biology. Moreover, the notion that ideasinhere in nature—a central position of idealist morphology(Richards, 2002)—has been rejected with an almost knee-jerk reac-tion by some vocal neo-Darwinians because, from their perspec-tive, ideas have no inherent reality. But if that were the case, itfollows that, because their criticism is itself an idea, it too wouldneed to be discounted. Evidently, we cannot escape from ideation,and thus the idealist morphologists were perhaps on to something.Richards (2002, p. 192) summarizes this eloquently: ‘‘It hardlyseems easier to believe the world is really a ball of mathematicalstrings that reveals itself to our consciousness as natural objectsof ordinary experience than to believe it is an organic structureof ideas that reveals itself in comparable fashion. Idealism cannotbe defeated, only forgotten.’’

There is a relatively recent and explicit literature that points tothe unfair assessment of Goethe’s way of science, but it has lan-guished below the radar of evolutionary biologists. Most notableare the epistemological contributions by philosopher of scienceBrady (1987, 1998) and physicist Bortoft (1996, 1998, 2012). Inaddition, there are numerous studies that either apply Goetheanmethodology to a plethora of natural phenomena or explore itsepistemology: besides Schad (1977, 2012), these include Amrineet al. (1987), Bockemühl (1998), Brook (1998), Seamon and Zajonc(1998), Lockley (1999, 2008), Steigerwald (2002), Verhulst (2003),Dornelas and Dornelas (2005), Ebach (2005), Holdrege (2005,2013), Holdrege and Talbott (2008), Steiner (2008), Williams andEbach (2008; especially chap. 3 and epilogue), Skaftnesmo(2009), and Suchantke (2009).

M.F. Riegner / Studies in History and Philosophy of Biological and Biomedical Sciences 44 (2013) 735–744 743

Whether or not one endorses the epistemological approach im-plicit in dynamic typology, as exemplified in a Goethean way ofscience, is contingent upon one’s understanding of this methodol-ogy. However, if one criticizes and offhandedly rejects such an ap-proach, one must at least be aware of what it is that one iscriticizing and ultimately discarding. As I’ve tried to show, thishas not been the case historically due to the confounding of staticand dynamic typological thinking. As mentioned previously, thisconfusion stems from the overlooked requirement to engage ourcognitive activity in a way in which we are unaccustomed. Suchan engagement requires more than a conceptual change or concep-tual reorganization (sensu Chi & Roscoe, 2002) and even more thana paradigm shift (sensu Kuhn, 1970), in which only the content ofthinking changes. Rather, it necessitates a conscious transformationof the cognitive activity itself, and therefore a transformation of thescientist him- or herself. This is the piece that has perenniallyeluded critics of Goethe’s way of science and the dynamic typolog-ical thinking it exemplifies. As Brady (1998, p. 84) points out, ‘‘Thewriters of scientific histories are unable to perceive what they can-not conceive.’’ Interestingly, Goethe himself alluded to this pitfall:

There is a delicate empiricism which makes itself utterly iden-tical with the object, thereby becoming true theory. But thisenhancement of our mental powers belongs to a highly evolvedage. (quoted in Miller, 1995, p. 307)

As I’ve attempted to show, the confluence of modern evolutionarydevelopmental biology with Goethe’s dynamic typology holdspromise in deepening our understanding of the origin, diversity,and limitations of biological form and how those forms manifestand change over time. In this sense, Goethe should be seen not sim-ply as a forerunner of contemporary evolutionary developmentalbiology but as providing a narrative that can contribute to the fur-ther development of a new archetypal biology.

Acknowledgments

I am grateful to the late Ron Brady for many hours of engagingconversations in his office at Ramapo College in 1987–88; I dedi-cate this article to his memory. I also thank Malte Ebach, CraigHoldrege, Trond Skaftnesmo, and John Wilkins for suggestions thatimproved an earlier draft of the manuscript, and Greg Radick andtwo anonymous reviewers for very helpful comments that guidedme in reshaping a more recent draft; of course, any misinterpreta-tions rest on my own shoulders. Prescott College deserves my grat-itude for awarding me a sabbatical leave in spring 2010, whichafforded me the time to gather my thoughts on this subject. Andfinally, I thank the many students over the years in my class Formand Pattern in Nature for helping me refine my own understandingof the ideas expressed herein.

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