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Buffon and the Concept of Species

PAUL L. FARBER

Department of General Science Oregon State University Corvallis, Oregon

His to r i an s of sc ience h a v e ce r t a in ly n o t over looked Buffon ' s c oncep t of species. H o w e v e r , a p e r u s a l of the l i t e r a tu re r evea l s an i ron ic s i tua t ion . E v e n t h o u g h Buf fon was the l e a d i n g n a t u r a l - is t of h is cen tu ry , the th i rd m o s t wide ly r e a d au tho r in F r a n c e , and one of the " four g rea t l igh ts of the E n l i g h t e n m e n t , " h i s w o r k has b e e n r e v i e w e d laxgely in its r e l a t i onsh ip to l a t e r thought . Accord ing ly , he is m o s t o f t en g iven the dub ious h o n o r of be ing c i ted as a p r e c u r s o r first of Cuvier , t h e n of Darwin . 1 A n d as is the case w i t h m o s t a l leged precursors , the i r f a m e and i m p o r t a n c e pa les w h e n c o m p a r e d to the m a j o r f igures fo r w h o m they act as ha rb inge r s . I n Buffon ' s case this s i t ua t i on is m o s t r eg re t t ab le , fo r h is c o n c e p t of species h a d an i m m e n s e i m p a c t on the b io logy of his day, and f u r t h e r m o r e it was an i n t e g r a l p a r t of the i n t e l l e c tua l f e r m e n t k n o w n as the E n l i g h t e n m e n t . A t h o r o u g h u n d e r s t a n d i n g of his t h o u g h t c a n he lp us a n s w e r a m u c h m o r e i m p o r t a n t ques t i on t h a n w h o t h o u g h t w h a t be fo re w h o m ; n a m e l y , w h a t was the s ta te of b io logy in the e i g h t e e n t h

1. Pierre Flourens, Buffon: Histoire de ses travaux et de ses iddes (Paris, 1844), the only full-scale study of Buffon'a thought, focuses on those aspects of Buffon's science relevant to the later zoology of Cuvier. The l.itetature discussing Bu_ffon and Darwin is extensive. Arthur Lovejoy, "Buffon and the Concept of Species," in Bentley Glass, ed., Forerunners of Darwin (Baltimore, 1959), reviews the multitudinous opinions concerning Buffon's relationship to Darwin vis-A-vis the mutability of species and lays most of them to rest by his careful analysis of the essential differences between Buffon's and Darwin's concepts. Jacques Boger, in his Les Sciences de la vie darts la pens~e fran~aise du XVIIIe si~cle (Paris, 1963), also de- cidedly challenges the more traditional account of Bu_ffon's species concept. In this work, Roger discusses Buffon's role as a Newtonian naturalist and describes the general outline of the development of Bu:ffon's ideas on species. Roger suggests that Buffon's ideas evolved on several different levels--classification, biology, the interpretation of l i fe--and that this explains his changing statements. The following account will attempt to illustrate a more integrated development of Buffon's thoughts on species and to suggest a more important historical role.

Journal of the History of Biology, vol. 5, no. 2 (Fall 1972), pp. 259-284.

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PAUL L. FARBER

century, and how did it relate to the general thought of the period. Buffon's concept of species, since it became the m a j o r definition of species in the late eighteenth century, is a good s tar t ing point for a general inquiry concerning Enl ightenment biology.

With the exception of the two translat ions and a few articles, the thirty-six volumes of the Histoire natureUe, g~ndrale et particuli~re comprise Buffon's oeuvres completes. 2 Since he generally published his work in the order in which he wrote it, a chronological survey of his r emarks in the Histoire natureUe will disclose the gradual evolution of his ideas.

FIRST STATEMENT

Nature progresses by unknown gradations and consequently does not submi t to our absolute divisions when pass ing by impercept ible nuances , f rom one species to another and often f rom one genus to another. Inevi tably there are a great number of equivocal species and in-between specimens tha t one does not know where to place and which throw our general systems into turmoil.3

Tha t was Buffon's first s t a tement on species. The context was impor tan t for it was polemical, a general a t tack on wha t he considered the abuses of artificial systems.4 To confound the

2. Buffon 's Histoire natureUe, g~n~rale et ~artieuli~re, publ i shed be tween 1749 and 1789, w a s divided into four sections: Histoire naturelle, gdn~rale et partivuli~re, auec la description du Cabinet du Roy (15 vols., 1749-1767), Histoire naturelIe des oiseaux (9 vols., 1770-1783), Supplement ?z l'Histoire naturelle (7 vols., 1774-1789), and the Histoire naturelle des rnineraux (5 vols., 1783-1788). Where possible, i t is advisable to use this first edition. The use of later edit ions requi res ex t reme care, fo r m a n y of t hem axe incomplete , n o t w i t h s t a n d i n g titles such as Oeuvres eornpldtes, etc. Moreover, n u m e r o u s n ine teen th -cen tu ry p r in t ings ( there are over fifty-one in F r ench alone) were upda ted to accommoda te n e w discoveries or "im- provemen t s " such as L innaeus ' classification, Cuvier 's classification, or notes by n ine teen th -cen tu ry biologists. The best la ter edit ion is J. L. Lanessan , ed., Oeuvres completes de Buffon (Paris, 1884-1885), w h i c h con ta ins Buffon 's collected correspondence. Where possible I have quoted f r o m J e a n Piveteau, ed., Oeuvres 1Jhilosophiques de Buffon (Paris, 1965), (hereaf te r re fer red to as O.P.) the m o s t readily available source for con- sultat ion. All o ther references are to the first edit ion (hereaf te r referred to as Histoire naturelle).

3. O.P., p. 10. Trans la t ions are by the author . 4. As early as 1744 Buffon had been p repa r ing some sort of cr i t ique and

in 1745 he wrote to a cor responden t in Geneva tha t he p l a n n e d to pub l i sh it in the first vo lume of h is proposed n a t u r a l history. For the letter, see Eugene Ritter, "Lettres de B u ~ o n et de Mauper tu i s adress~es h Ja laber t , " Revue d'histoire litt@raire de France, 8 (1901), 653.

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systematists Buffon was utilizing a widely held belief, the Chain of Being. 5 Systems, he claimed, were based on a metaphysical error, the assumption that distinct divisions exist in nature. Ingenious attempts by naturalists to establish elaborate hier- archies and criteria for ranking individuals and groups of individuals, therefore, did violence to our knowledge of the order in nature.

Buffon was not saying that all systems were bad; quite the opposite: "The result of what we have just shown," he sum- marized, "is that there are two equally dangerous obstacles in the study of natural history. The first is having no method, and the second is desiring to subsume everything under a specific system." 6 The one extreme led to chaos, whereas the other led to idle speculation. What Buffon opposed was the construction of artificial systems based on a single characteristic, not the construction of a natural system resulting f rom a study of the entire organism. Using botany as an example, he surveyed numerous systems and concluded:

After this honest exposition of the foundations on which different systems of botany have been built, it is easy to see that the major fault with all of them is a metaphysical error in the very principle of these systems. The error consists of disregarding the course of Nature, which always manifests itself by nuances, and of wishing to consider the whole by only one of its p a r t s . . . I t seems to me that the sole way of construct ing a natura l and instructive method is to place together those things that resemble one another and to separate those that differ. I f individuals have a perfect re- semblance, or if their differences are so small that they can scarcely be noticed, they will be of the same species.7

It is difficult to ascertain Buffon's actual thought on species in his first discourse. On the one hand he used the Chain of Being to attack artificial systems and appears to have been espousing a Nominalis t philosophy; but on the other hand he supported natural systems presumably based on real species.

The apparent inconsistency can be resolved by considering

5. For a genera l d iscuss ion of this concept, see Arthu~ Lovejoy, The Great Chain of Being (Cambridge, 1936). For a d iscuss ion of the concept i n e igh teen th-cen tury biology, see Henr i Daudin , De Linn~ d Jussieu. Les mdthodes de la classification et ridde de sdrie en botanique et en zoologie (1740--1790) (Paris, 1926).

6. O.P., pp. 13-14. 7. Ibid., p. 13.

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t h e n e x t a r t i c le on a n i m a l s p u b l i s h e d d u r i n g the s a m e year . s I n w h a t a p p e a r s to be a def in i t ive s t a t e m e n t Buf fon c l ea r ly a n d exp l i c i t l y a f f i rmed h i s be l i e f in the ex i s t ence of f ixed e t e r n a l spec ies :

As a d m i r a b l e a w o r k as i t a p p e a r s to us , i t is no t in the i n d i v i d u a l t h a t w e f ind the g r e a t e s t ma rve l . I t is i n the suc- cess ion , in the r e n e w a l , a n d i n the c o n t i n u a n c e of spec ies t h a t N a t u r e r evea l s he r s e l f as c o m p l e t e l y i nconce ivab l e . Th i s ab i l i ty of se l f - rep l i ca t ion , w h i c h r e s ides in a n i m a l s and p l a n t s , th i s type of c o n t i n u a l u n i t y w h i c h s e e m s to be e t e rna l , th i s e n g e n d e r i n g v i r t ue w h i c h exe r t s i t se l f p e r p e t u a l l y w i t h o u t eve r d e s t r o y i n g i t se l f , is fo r us a m y s t e r y w h o s e dep th , i t s eems , is n o t open to h u m a n scru t iny .9

F r o m the above q u o t a t i o n i t c a n be seen t h a t Buffon a c c e p t e d the c o m m o n o p i n i o n t h a t spec ies we re c o n s t a n t a n d e t e rna l , a l t h o u g h w h a t he a c t u a l l y f o u n d i n t r i g u i n g a b o u t the n o t i o n w a s the succe s s ion of s i m i l a r i n d i v i d u a l s in n a t u r e . His p r o b l e m w i t h the concep t , w h i c h in p a r t e x p l a i n e d h i s o f t e n a m b i g u o u s l a n g u a g e , w a s t h a t he h a d no p h i l o s o p h i c b a s e on w h i c h to g r o u n d it. Clear ly , fo r a m a n of h i s p e r s u a s i o n s , a spec ies cou ld n o t be a n essence , a n ente lechy , or the l i n e a l d e s c e n d a n t s of a n o r i g i n a l pa i r ; t he se we re a l l t h e o r e t i c a l t e r m s f r o m s y s t e m s t h a t the p h i l o s o p h e s i n g e n e r a l a n d Buf fon in p a r t i c u l a r , f o u n d re- p u g n a n t . Yet t he re s e e m e d to be s o m e t h i n g in n a t u r e t h a t cou ld be i so l a t ed a n d c l ea r ly iden t i f i ed . P a r t l y by m o r p h o l o g y , b u t m o s t d r a m a t i c a l l y by the c o n s t a n t s u c c e s s i o n of l ike f o r m s , spec ies were r ecogn izab le . The so lu t i on t h a t Buffon se t t l ed on was c lever a n d a p p r o p r i a t e . H e fe l t the need to s u p p l y a de f in i t ion fo r th is b a s i c c o n c e p t a n d gave a f u n c t i o n a l one; t h a t is, he gave c r i t e r i a by w h i c h one cou ld dec ide i f a n i n d i v i d u a l b e l o n g e d to a spec ies w i t h o u t c o m m i t t i n g h i m s e l f to a n y m e t a p h y s i c a l pos i t ion . The def in i t ion , w h i c h re f lec ted h i s f a s c i n a t i o n w i t h the succes s ion of i n d i v i d u a l s , r e a d as fo l lows : "One shou ld r e g a r d as b e l o n g i n g to the s a m e spec ies those a n i m a l s w h o by w a y of c o p u l a t i o n c a n

8. Buffon published the fLrst three volumes of the Histoire naturelle in 1749. He described no specific animals in these introductory volumes, but instead he turned his attention to questions of methodology, the general nature of both man and animals, the concept of species, generation, sense perception, anthropology, cosmology, and geology. These three volumes may be considered as a unit since they were published the same year after a decade of research, They were presented as a unit, and they were reviewed by his contemporaries as such. The remaining 12 volumes of the His~oire naturelle, 9dndrale et part~culi~re described the quadrupeds.

9. O.P., p. 233.

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Buffon a n d the C o n c e p t of Spec ies

p e r p e t u a t e t h e m s e l v e s a n d c o n s e r v e the c h a r a c t e r of the spec ies , a n d as b e l o n g i n g to d i f f e r en t spec ies those w h o by the s a m e m e a n s c a n n o t p r o d u c e a n y t h i n g . " 10

A l t h o u g h Buffon n e a t l y avo ided a n y m e t a p h y s i c a l c o m m i t - m e n t w i t h h is f i rs t de f in i t i on of species , in the s a m e v o l u m e h e n o n e t h e l e s s l a i d the g r o u n d w o r k fo r a m o r e p h i l o s o p h i c u n d e r - s t a n d i n g . He d id th i s by d e s c r i b i n g a n e w se t of on to log i ca l en t i t i e s p r o p o s e d to e x p l a i n o r g a n i c gene ra t i on .

T H E M O U L E I N T ~ R I E U R A N D T H E MOL12CULES O R G A N I Q U E S

Buffon ' s t heo ry of g e n e r a t i o n 11 w a s the p r o d u c t of s e ve ra l y e a r s of r e s e a r c h a n d e x p e r i m e n t a t i o n 12 a n d w a s c o n s t r u c t e d on a n a n a l o g y to a p h y s i c a l m o d e l in f ac t , the p h y s i c a l m o d e l o f the e i g h t e e n t h c e n t u r y , N e w t o n ' s h y p o t h e s i s of u n i v e r s a l g r av i t a - t ion. To a c c o u n t fo r the f o r m a n d f u n c t i o n of i n d i v i d u a l l i v ing be ings , Buffon pos i t ed the e x i s t e n c e of a fo rce ca l l ed the mouIe intdrieur, a n d w a s ve ry exp l i c i t i n n o t i n g the p a r a l l e l b e t w e e n i t a n d grav i ty . I n one of the f i rs t m a j o r e x p l i c a t i o n s of h is t h e o r y h e w r o t e :

T h e r e a re in N a t u r e , then , powers , even ve ry ac t ive ones , t h a t i n t i m a t e l y p e n e t r a t e the p a r t s of bodies . W e c a n n e v e r h a v e a c l ea r i d e a of t h e m , howeve r , fo r as p r e v i o u s l y s t a t ed , t hey a re n o t e x t e r n a l a n d t h e r e f o r e we c a n n e v e r p e r c e i v e t h e m di rec t ly . N e v e r t h e l e s s , we c a n c o m p a r e t he i r effects a n d t ry by a n a l o g y to give a n a c c o u n t of the ef fec ts of p o w e r s of the s a m e type . . . . T h e r e ex is t s in N a t u r e a p o w e r p e n e t r a t - i n g to t he i n t e r n a l p a r t s of bod ies t h a t we ca l l g rav i ty , I a p p r e h e n d the i d e a of a moule intdrieur as a n a l o g o u s to th i s power.13

The mou le intdrieur p l a y e d a key ro le i n Buffon ' s t h e o r y o f g e n e r a t i o n , h is c o n c e p t of spec ies , a n d h is g e n e r a l phys io logy . A l t h o u g h i t a l l eged ly r e s e m b l e d grav i ty , the mouIe intdrieur d id

10. Ibid., p. 236. 11. Roger, Les sciences de la vie, very carefully analyzes Buffon's theory

of generation and discusses its theoretical background and context. 12. As early as 1746 Buffon had thought through the principles of his

theory and had begun writing it out. The Buffon Dossier in the Archives de l'Academie des Sciences contains a document filed by Buffon with the secretary dated May 18, 1748 which states, "'Le 9 f~vrier 1746, j 'ai com- menc~ un Traitd sur la Generation, qui est maintenant enti~rement achev~." The rest of the document summarizes his later published theory of generation.

13. O.P., p. 244.

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not act on brute matter, but instead it affected an analogous substance, the rnoldcules organiques, another theoretical entity that he introduced: "There exist in Nature an infinite number of living organic particles, which are of the same substance as that found in living bodies, just as there are an infinite number of particles of brute mat ter that are similar to ordinary inanimate bodies." 14

In his first volumes Buffon placed great emphasis on these basic particles of life. Although he claimed that the moule intdrieur was a force in nature responsible for the internal and external form of individuals, when he actually explained the mechanism of reproduction he imparted to these organic molecules the major active role and had the moule int~rieur serve more as a template than as an organizing force.

In his theory of generation, Buffon proposed that excess organic molecules f rom all parts of the body formed the seminal fluids, and that when male and female seminal fluids were mixed the active particles counterbalanced one another, assumed positions analogous to the ones they had in each parent, and that a primitive embryo resulted that had only to expand in the mother 's womb to form a new individual. Just how the moule intdrieur replicated did not figure explicitly in Buffon's early account and we are left to surmise that somehow the proper concourse of organic molecules constituted its origin. This is very unsatisfactory since one may legitimately question in what sense the moule intdrieur constituted a basic force in nature.

Another problem surrounding Buffon's theory of generation involved the validity of his analogy between the rnoule intdrieur and gravity. The moule intdrieur resembled gravity in the sense that both forces were revealed only through their effects, and that their causes were not known. The functions that they performed, however, were radically different. Newton had written of gravity as a universal force, one common to all matter, and, in principle, a measure of its mass; whereas Buffon described the rnou/e intdrieur as a collection of individual forces, influencing some organic molecules and not others. The mode by which the two forces organized mat ter also differed. Gravity was a universal property of all mat ter which acted uniformly, in contrast with the moule intdrieur, which was a teleological force that arranged organic mat ter according to an intrinsic plan. When Buffon claimed that the raouIe int~rieur was analogous to gravity, he mus t have been referring to Newton's s tatement relating to active principles in the thirty-first query of the Opticks, which

14. Ibid. , p. 239.

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condoned the introduction of other classes of force into the explanation of nature. 15

If Buffon was extending the concept of force when he discussed the m o u l e in tdr ieur , he was doing it in a manner foreign to the spirit of Newton's use of force. For instead of a constant law of nature, the rnoule in tdr ieur was neither constant nor conserved: it came into being (reproduct ion) and eventually died out (death of the organism). Although Buffon followed Newton's science in the sense that he admitted forces into the explanation of nature, the force that Buffon employed for his natura l history differed strikingly f rom any force about which Newton had ever written. This, of course, is not to say that a force like the m o u l e in tdr ieur could not exist, but only to point out that the analogy with gravity was tenuous, and therefore its ontological status was more suspect than Buffon would have his readers believe.

It is important to keep in mind the philosophical difficulties concerning the m o u l e intdrieur , for it was a concept that was relevant to Buffon's discussion of species. By establishing a breeding criterion for the recognition of individuals of the same species, Buffon associated the concept of the m o u l e in tdr ieur with that of the concept of species. At this stage he did not follow out the potential ramifications implicit in the association; however, once connected it was not a large step to consider them as ontologically related.

ELABORATION

In 1753, with the publication of the four th volume of the His to ire na ture l le , the first of Buffon's descriptions of specific animals appeared. In this volume and in the subsequent one (vol. 5, 1755) Buffon elaborated on his earlier definition of species. Although his remarks were dispersed among several articles, it is not difficult to reconstruct the basic idea. In the preface, a short discussion on domestication, Buffon reaffirmed his contentions that species were fixed and that al though m a n may affect the appearance of some individuals, species belonged to the domain of nature and were therefore constant.16

Buffon's most explicit statements followed the preface and were

15. This aspect of Newton's work has been discussed at length by I. B. Cohen, Franklin and Newton (Philadelphia, 1956), Hdl~ne Metzger, Newton, Stahl, Boerhaave et la doctrine chimique (Paris, 1930), and T. S. Hall, "On Biological Analogs of Newtoniau Paradigms," Philosophy of Science, 35 (1968), 6-27.

16. O.P., p. 352.

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in the first two articles of the four th volume, the descriptions of the horse and the ass. In the first of these he wrote that for each species there was a first model, a prototype:

There exists in nature a general prototype ill each species upon which all individuals are molded. The individuals, however, are altered or improved, depending on the circumstances, in the process of realization. Relative to certain characteristics, then, there is an irregular appearance in the succession of individuals, yet at the same time, there is a striking con- stancy in the species considered as a whole. The first animal, the first horse, for example, was the exterior model and the internal mold f rom which all past, present, and future horses have been f o r m e d Y

We should not conclude f rom the above quotation that Buffon espoused an Idealism or a Platonic doctrine, for he qualified his s tatement immediately: "But this model," he continued,

of which we know only copies, could alter or improve itself in impart ing its form or in multiplying. The original imprint subsists in its entirety in each individual; and although there have existed millions of these, not one of them is exactly like another, nor consequently, to the model of which it bears the imprint. This difference, which demonstrates how far away nature is f rom making anything absolute, and how much she can vary her works, is found in the h u m a n species, in those of all the animals, and of all the plants. Is

Buffon's emphasis was on the genetic link that united individuals to a supposedly historical entity, rather than on a con- templation of their form. His viewpoint was explicitly presented in the article on the ass, which was subsequent to that on the horse :

An individual is a solitary, isolated, detached being that has nothing in common with others except that it resembles, or more commonly, differs f rom them. Although all similar individuals that exist on the surface of the earth are regarded as composing the species of these individuals, it is neither the number nor the collection of these similar individuals that forms the species. It is the constant succession and the unin. terrupted renewal of these individuals that constitutes it. 19

17. Histoire naturelle, IV (1753), 215-216, 18. Ibid. 19. Ibid., PP. 384--385.

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Typical of his early distrust of the abstract, Buffon insisted that even his concept of species was only a general term indicat- ing the succession of similar forms, ra ther than an ontological entity. He nonetheless used species as his basic unit and claimed that of all taxonomical grouping it was the most true to nature 's plan:

It is, then, in the characteristic diversity of species that the intervals between the nuances of nature are the most noticeable and best marked. One could even say that these intervals between species are the most uni form and the least variable of all, since one can always draw a line of separation between two species, that is, between two successions of individuals that can not reproduce with each other. This distinction is the strongest that we have in natural history. All the other distinc- t, ions that one could choose for comparing individuals would not be as constant, as real, or as certain. These intervals [species] will be, therefore, the only divisions to be found in our work. We will not divide a group of beings in any way other than they are in effect. Each species----each succession of individuals that can successfully reproduce with each other - -w i l l be considered as a unit and treated separately. We will not use families, genera, orders, and classes, any more than nature does.

A species, then, is only a constant succession of similar individuals that can reproduce together. [emphasis mine] 20

The above quotation, hereafter referred to as Buffon's definition of 1753, was extremely important , for it clearly stated his early beliefs and contained the seeds of his later emendations. In 1749 Buffon had been polemical when he discussed species, and therefore his earlier pronouncements were incomplete. He was led to elaborate on the subject in 1753 in order to begin his discussions of individual species. Although Buffon denied that species had any ontological status, he committed himself to the belief that they were distinct units that could be functionally differentiated. Moreover, they were entities that had a history and a future (unless ext inct) ; therefore they were not static: their past was impor tant for an unders tanding of their present. For ff a species was a succession of individuals, only its inter- action with the environment could explain the origins of different races and breeds, Buffon reasoned.

By placing the weight of his emphasis on the succession of

20. Ibid.

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individuals in defining a species, Buffon strengthened its earlier association with the moule intdrieur. Two animals belonged to the same species if they could successfully breed together, Buffon claimed, and a species was a long chain of such breed- ings. It would seem then that the moule intdrieur, which was responsible for individual form, mus t be responsible for the continuation of the species. Buffon did not specifically state this, al though it was implicit in his writing.

Buffon's contemporaries were aware of the signficance of his definition of 1753. When referring to Buffon, other naturalists most often quoted f rom his article on the ass in regard to the concept of species. Michael Adanson, for example, who in the introduction of his Familles des plantes (1763) reviewed all previous classifications and concepts of species, singled out the definition of 1753 in the length section on Buffon. The En- cyclop~die gave for its definition of the natural history meaning of the word esp~ce, a verbatim quotation from the article on the ass.

EXPANSION

Buffon never repudiated his definition of 1753. In later years, however, he expanded it to encompass new information and broader theoretical speculations. These modifications can, for the most part, be related to several significant events in Buffon's career after 1753 that influenced his work. Between 1756 and 1763 there were at least three that should be mentioned, all of which involve additional empirical data.

The first of these has to do with what are now called hybrids. In his article on the goat (vol. 5, 1755) Buffon wrote that goats and sheep belonged to separate species, although, as with the case of the horse and the ass, they were known to interbreed and produce offspring. Whether or not the mulets were sterile or fertile was undetermined at the time. Since Buffon's definition of species explicitly stated that two animals that can reproduce successfully belonged to the same species, we can unders tand his interest in ascertaining exact information concerning crossbreeding. In the Suppldment Buffon revealed that as early as 1751 he was engaged in breeding experiments at his native Montbard, ~1 and for m a n y years he kept records of matings between goats and sheep, and between dogs and wolves. In 1755, when he published his article on the goat, he had no idea how far he could go with interbreeding, but he was intrigued by the

21. Histoire naturelle, SulJpldment, I I I (1776), 3-5 .

9.68

Buf fon and the Concep t of Species

q u e s t i o n and co l lec ted as m u c h i n f o r m a t i o n f r o m his f r i ends and f r o m the c u r r e n t l i t e r a tu re as he could, 22 A n o t h e r f ac to r r e l a t ed to Buffon ' s i n t e r e s t in c ros sb reed ing and the concep t of species was the acqu i s i t i on in 1757 of the deceased n a t u r a l i s t R ~ a u m u r ' s c a b i n e t fo r the J a r d i n du Roi, f r o m w h i c h he ser iously b e g a n to compi l e m a t e r i a l fo r the H i s t o i r e n a t u r e l l e des o i s e a u x .

This was no s imple task, fo r the R 6 a u m u r co l lec t ion c o n t a i n e d over f o u r h u n d r e d s tuf fed bi rds plus a w e a l t h of m a t e r i a l f r o m

c o r r e s p o n d e n t s in the N e w World. 23 Buf fon h a d to c o n t e n d w i t h d i f fe ren t p rob l ems w h e n he at-

t e m p t e d to pub l i sh his o rn i tho logy , and i t was a p ro j ec t t h a t i nvo lved twen ty yea r s of r e s e a r c h and the h e l p of n u m e r o u s col labora tors . T h e m o s t sa l i en t p r o b l e m c o n c e r n e d the sheer q u a n t i t y of m a t e r i a l to be c o v e r e d - - o v e r t en t imes the n u m b e r of quad rupeds . As we sha l l see be low, the w a y he chose to reso lve the p r o b l e m was to supply his r e a d e r w i t h i l l u s t r a t ions of i n d i v i d u a l species and to g roup s im i l a r b i rds in g e n e r a or f a m i l i e s - - B u f f o n did no t d i s t i n g u i s h b e t w e e n the taxa.

S ince Buf fon w a s c o n s i d e r i n g a h i s to ry of b i rds as ear ly as the 1750's, i t was qui te poss ible t h a t h is t h o u g h t s on the b i rds i n f l uenced his pe r cep t i on of the q u a d r u p e d s and his a t t e m p t s to s y s t e m a t i z e them. For a l t h o u g h Buf fon did no t approve of u s ing h i g h e r t a x a in the 1750's, the b i rds were ce r t a in ly an i n s t a n c e w h e r e the i r e m p l o y m e n t wou ld be p r a g m a t i c a l l y wise, and ff he c o n t e m p l a t e d the i r use w i t h birds, he m i g h t wel l h a v e cons ide red

22. Many of these reports found their way into the later volumes of the Histoire naturelle. For example, in the Histoire naturelle des oiseaux, II (1771), 162, Buffon referred to a report that George Edwards made in 1759 concerning the mating of a pheasant and a turkey, and in the Supplement , III (1776), he reported the attempt, made at the menagerie at Versailles, to breed a zebra and an ass.

23. Buffon was director of the Jardin du ttoi which possessed one of the largest and most important natural history collections in Europe. The cabinet, however, was singularly poor in birds, a fault that Buffon rectified by having the king place the R6auraur materials at the Jardin du Roi. Edouard Lamy, Les Cabinets d'histoire naturelle en France au XVII Ie sidcle et le Cabinet du Roi (1635-1793) (Paris, 1930), describes the natural history collection at the Jardin du Roi. Lamy draws heavily on Antoine- Joseph Dezallier d'Argenville, l'Histoire naturelle ~claircie dans deux de ses parties principles, la lithoIogie et la conchyliologie (Paris, 1742), which describes the famous cabinets of Europe on pp. 198-230, and also on a work by the lattor's son, Antoine Nicolas d'Axgenville, Conchyliologie nouvelle et portative ou collection de coquilles (Paris, 1764), which also lists famous cabinets on pp. 309-328. For a more modern description of what the natural history collection at the Jardin du Roi was like in Buffon's time, see Yves Laissus, "Los Cabinets d'histoire naturelle," and "Le Jardin du Roi," in Ren6 Taton, ed., Ense ignemen t et di f fusion des sciences en France au XVIII" si~cle (Paris, 1964).

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the same method for the quadrupeds. Buffon did not possess the resources to write lengthy articles on each species of bird; even if he had, the project would, in theory, have involved one hundred and fifty volumes (there being 15 volumes of quadrupeds and the birds number ing 10 times that l) . If we consider only the first descriptive volume of the later Histoire natureUe des oiseaux (vol. 2, 1771) we can sense the obvious advantage of grouping similar birds into families, for in the eleven articles printed there, eighty-eight species were t rea ted- -a lmos t half the numerical amount of the quadrupeds.

What lent more than just pragmat ic weight to this method was the widely held belief that there was considerably more interbreeding among the birds than among the higher animals. 24 If it was the case that birds of different species could interbreed - -pa r t i cu la r ly ones that seemed to display family character- i s t i cs - - then according to Buffon's beliefs they must have some genetic relationship. Perhaps what were normally regarded as different species were actually varieties. Perhaps it was a process of degeneration and hybridization that accounted for such large families as those of the blackbirds, the pigeons, or the fiy- catchers. Whether or not Buffon actually entertained these propositions is, of course, impossible to know for sure, since there are no extant letters or manuscripts f rom the period that bear on the subject. Moreover, we do not even know exactly which birds he worked on during the 1750's.

I do not believe, however, that we are forced to dismiss the potential influence of his ornithology; for by 1757, with the acquisition of R6aumur 's cabinet, he did have a large collection and was seriously considering a natural history of birds. In addition, he was aware of their interbreeding and certainly mus t have considered its implications. Therefore, the problems of organizing his work on the birds were on his mind while he was contemplat ing a system for the quadrupeds, and may well have influenced his thoughts on the relationship of closely related species and the existence of higher taxa.

The influx of scientific information brought to Europe f rom Africa and the New World by such men as Artur, Adanson, LaBorde, and Shaw, as well as the explorations of Eastern Europe and Russia by Gmelin and Pallas, was the third factor that came to bear on Buffon's work, 25 in that he began to spec-

24. E.g., see John Ray, The Ornithology (London, 1678), p. 12. Bu.ffon quite clearly expressed his belief in the high degree of interbreeding among the birds in his article, "'Plan de rouvrage," Histoire naturelle, Oiseaux, I (1770).

25. Although information from explorations had been arriving since the

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ulate on the re la t ionship of New and Old World animals. This, coupled with his experiences as a natural is t , suggested to h im a new significance for some of his earlier generalizations. For instance, the New World, according to Buffon, was more recent and less perfect than the Old World. I ts cl imate was colder and more humid; consequently its f lora and f a u n a were fewer in number , less fertile, and less perfect. I t was unders tandable , then, that explorers in the New World found no large quadrupeds to compare wi th the elephant , rhinoceros, lion, or tiger, nor did they find anyth ing like the domest ic an imals of the Old World.

More important ly , the similari ty of nor thern animals in both the Old and New Worlds led Buffon to consider the possibility of a previously exist ing landbridge, probably between Nor thern Asia and Nor th America. Buffon found this prospect part icular ly ex- cit ing in l ight of the reports f r o m Siberia and f rom Nor th Amer ica conf i rming the fac t that European animals degenerate in new envi ronments af ter a few generations. Perhaps, he speculated, all the an imals of the New World were actually degenerated fo rms of Old World animals. "Without revers ing the order of Nature ," he wrote,

it could possibly be tha t all the an imals of the New World are basically the same as those of the Old World f rom w h o m they originated. One could fu r the r suggest tha t hav ing been sep- arated f rom the r ema in ing animals by i mmense seas or by impassab le land, and with t ime having received all the im- pressions and suffered all the effects of the cl imate, which itself has been changed by the very causes that produced the separat ion, these an imals have shrunk, have become distorted, etc. This, however, should not h inder us f r o m regarding them present ly as an imals of different species.e6

As early as 1761, then, Buffon was considering the possibility that two or more species migh t come f rom a c o m m o n stock,

s ix teenth century, due to the enormous colonial expans ion of France and the serious organized efforts of profess ional na tura l i s t s there o c c u r r e d

dur ing the e ighteenth century a dramat ic upgrad ing in the quant i ty and quali ty of the incoming scientific informat ion. Buffon specifically stated tha t he quest ioned any descriptions tha t were over Fifty years old, s o

improved h ad the collecting of scientific mater ia l become. Some of the n e w

data are discussed in Paul Fournier , Voyages et ddcouvertes scienti~ques des rnissionnaires Fran~ais (Paris, 1932), Ad. Davy de Virville, Histoire de la Botanique (Paris, 1954), and Raymond Stearns, Science in the British Colonies of America (Uthana , 1970).

26. O.P., p. 382.

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although he was not prepared to advance any more than a speculation. To do otherwise would require more information, a new theory of geology, an expansion of his theory of generation, an expansion of his concept of species, a theory of degeneration, and new breeding experiments. These considerations became relevant however, at a time when he was receiving new reports on the crossbreeding between individuals of different species and when he was considering the generic classification of birds. His later theory was not yet formulated, for when it appeared it was significantly different f rom the above-quoted speculation. It was possible, nonetheless, that he already was considering it and collecting relevant data.

INTERIM

The three factors that I suggest played a role in the development of Buffon's thinking between 1756 and 1763 - - t ha t is, new breeding information, work on the birds, and consideration of the relationship between New and Old World an imals - - seems to have had a noticeable impact on his work in the two years before he finally published the synthesis of his new ideas in 1766. In the three volumes that he published during the years 1764 and 1765 he greatly expanded his views and introduced new concepts that played key roles in his mature system.

The single most important development was Buffon's first reduction of several species to one, or what we might view as his explanation of the origin of genera. In his article entitled, "Le Buftte, le Bonasus, rAurochs, le Bison et le Zebu" (vol. 11, 1764), Buffon reduced all the known domestic cattle to two species, the buffalo and the c o w Y The rest were considered merely as varieties that developed due to the influence of the environment and domestication. This reduction was of para- mount importance for his later work, in that it set a precedent for organizing material by natural groups which were ordinarily considered to consist of several different species.

In the next article, "Le Mouflon et les autres brebis," he went a step further by presenting all the known sheep as degenerations of a primitive wild type. Although he still rejected the concept of genera as used by nomenclaturists such as Linnaeus and Brisson, he modified his earlier opinion by admitt ing that m a n could create genera by domestication:

27. At this time Buffon believed that the buffalo and the cow could not successfully breed, and that therefore they were different species. Later he modified his opinion.

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It seemed necessary in composing the natural history of wild animals to consider each of them independently without recourse to genera. We believe on the contrary, however, that we must use genera in a natural history of domestic animals. In nature there are only individuals and series of individuals, i.e., species. We have not had an influence on those animals that are independent of us; however, we have altered, modified, and changed domestic animals. We have created, then, real physical genera, quite different, to be sure, f rom the arbitrary and metaphysical genera that exist only in the mind. These physical genera are composed of species that we have worked on, modified, and changed. All the species, al though differently altered by the hand of man, have a common and unique origin in nature. The entire genus mus t have been formed f rom one species. ~s

Buffon was quite explicit that only the hand of m a n had created genera. However, if m a n had modified animals by placing them in new environments, feeding them certain foods, and selecting desirable individuals for breeding, why not consider the hand of nature also? What if Buffon realized that certain wild animals of different species could successfully interbreed? What if by considering the history of the earth he suspected that our planet was more ancient than previously believed, and thus nature therefore had more time to work on the character of species? If he began to work on a group of animals that were far more numerous in species than the quadrupeds, would he still want to main ta in that each was a separate creation, even if m a n y of them seemed to fall into natural groups? What would be the implications for the quadrupeds he had already described?

Considering the information that was available to Buffon in the years 1756-63, it is difficult to believe that some of these queries did not cross his mind. In light of his later development, they appear to be the very questions that he asked himself.

Buffon did not publically discuss these matters until 1766; however, as we have seen, lie did propose a limited use of genera for the first time. His most extended philosophic remarks presented during the years 1764-65 ignored for the most part the progress he had made in considering the concept of species, in order to stress the more universal aspects of natural history. After so m a n y volumes of details, Buffon felt that he was called upon to provide some philosophic reflections. In two short

28. Histoire naturelle, XI (1764), 369.

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chapters, "De la Nature. Premiere Vue!" and "Seconde Vue !" he stressed that nature was a system of universal laws and re- asserted his belief in the Newtonian cosmos of forces acting on matter. Once again he claimed that the moule int~rieur was analogous to gravity and responsible for growth and reproduction. His remarks on species were somewhat confused, He claimed that each species had an eternal immutable form, and wrote of the moule intdrieur as if it were the ins t rument that carried this form from generation to generation:

Nature never deviates f rom the laws that have been prescribed to her. She does not alter in any way the plans that have been traced for her, and in all her works she bears the stamp of the Eternal. This divine imprint, unalterable prototype of ex- istences, is the model whose traits are expressed in indelible and pronounced characters forever. It is an ever new model, of which the number of molds or cop ies - -no matter how great - - o n l y serves to r e n e w . . . In each species the first individuals served as the model for all their descendants. 29

Buffon recognized, however, that individuals varied and that some species had more variation than others:

The imprint of each species is a type whose principal traits are impressed in permanent indelible characters forever. How- ever, all accidental characteristics vary. No individual per- fectly resembles another, and no species exists with out a great number of v a r i e t i e s . . . All species, then, are subject to purely individual differences. Constant varieties and those that perpetuate themselves for generations, however, do not per- tain equally to all, for the higher the species the stronger is its type and the less it admits of varieties. 3o

In these grandes rues Buffon attempted to go beyond his 1753 philosophically uncommit ted definition of species by writing of the moule intdrieur as a permanent imprint. At the same time he wanted to account for the variation to be found in nature. He compromised by stating that variation was a funct ion of the strength of the imprint. One may sympathize with Buffon's at tempt to put the study of natural history on a more lofty plane, but he clearly was getting himself involved in problems of consistency when he published his overviews on nature. For how could a force such as the moule intdrieur, supposedly analogous

29. O.P., pp. 31-37. 30. Ibid., p. 38.

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to gravity, be responsible for both the eternal immutable species imprint as well as specific variations accumulated f rom one generation to another? How could such a force admit of greater or lesser intensity? And similarly, how could the environment, that is, other forces, influence its expression?

Buffon did not ask these questions, or ff he did, he made no public statements to enlighten us as to his answers. For this reason m a n y of his contemporaries and successors considered t h e m o u l e i n t ~ r i e u r meaningless. 31 It may also explain why his definition of 1753 was more often quoted than his later formula- tions. By stressing the concept of species as based on a permanent imprint Buffon had made a premature step toward supplying his natura l history with a philosophic base. It was not his last attempt, and in the following year he published a more significant and sophisticated speculation.

SYNTHESIS

For Buffon, 1766 was a pivotal year. He had earlier given a definition of species, which between 1749 and 1765 he had elaborated and expanded. Simultaneously, he had been considering several relevant problems in natural history and he had been collecting empirical information. By 1766 he had essen- tially completed his research on the quadrupeds, and in the last major volume of the fixst section of the H i s t o i r e n a t u r e l l e he published a chapter 32 that was intended to summarize the enormous project he had just concluded: the complete natura l history of the quadrupeds. The chapter was more than a summing up of what had come before. In it Buffon presented a natural system of classification by which he reduced the number of two hundred quadrupeds to thirty-eight families. These families were based upon morphological similarities, geographical dis- tribution, and an expanded concept of species.

His a rgument began with a discussion of the influence of the environment, a subject that he had repeatedly stressed in his earlier volumes. He attempted to demonstrate that the appearance of m a n y of the varieties found in nature or among domesti- cated beasts could be explained by the action of the environment

31. E.g., the posthumous work of Chretien-Guillaume Lamoignon Malesherbes, Observations de Lamoignon-Malesherbes sur L'Histoire Naturelle G~ngrale et Particuli~re de Buffon et Daubenton (Paris, 1798). Flourens, Buffon, p. 70, remarked "C'est pour expliquer un fait, imaginer un mot."

32. "De la d~g~n~ration des anirnaux,'" Histoire naturelle, XIV (1766).

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PAUL L. FARBER

or the influence of their diet. F rom these accepted views he moved to consider a more dar ing one:

After consider ing variet ies tha t represent pa r t i cu la r changes in each species, a more impor t an t considera t ion with fu r the r reach ing consequences presents i tself : tha t of the changing species themselves. I t is this older and f rom time i m m e m or i a l degenera t ion tha t seems to have been made in each family , or if one wishes in each of the genera, under which we can place s imi la r ne ighbor ing species. 33

W h a t Buffon had in mind was the creat ion of na tu ra l genera, someth ing tha t he had a t t r ibuted to m a n alone in 1764, but now regarded as the no rma l course of nature . For each fami ly (he used the words familIe and genre i n t e r changeab ly ) , according to Buffon, there was a premier souche tha t through t ime had degenera ted into several recognizable var ie t ies wha t we normal ly call species. Tha t these were all descendants f rom a common ancestor was at tes ted to by their morphologica l s imi lar i ty and thei r abil i ty to interbreed. Their fer t i l i ty was something tha t Buffon had come to believe due to the in fo rmat ion tha t he had accumula ted on the exis tence of fert i le mulets.8~

Another way of descr ibing Buffon's na t u r a l f ami ly is to say tha t i t was an extended species consis t ing of members tha t could in te rbreed and tha t had morphologica l s imilari t ies . This is a more accurate charac te r iza t ion than c la iming tha t he was advanc ing a theory of t r ans format ion , 35 for Buffon held tha t in most cases the premier souche was still ex tan t and could usual ly be recognized. In the la rger an imals there exis ted ei ther a solitary species, or a premier souche with one or two cons tan t varieties. For example , the horse he considered the premier souche of the horse family, and the ass and zebra as recognizable degenerat ions . There were var ie t ies of horses also; however, these were not as s t r ik ing as the zebra and ass, which, due to a long period of degenerat ion, had different ia ted greatly. In t ime, i t was possible tha t a present var ie ty of the horse could develop into a seemingly independen t f o r m - - t h e ass and the zebra s tar ted off as var ie t ies m a n y thousands of years ago. Conversely,

33. O.P., p. 401. 34. I t should be noted tha t Buffon actual ly had very little empir ica l

i n f o r m a t i o n to back up the c la im tha t the extent of hybr id iza t ion w a s so great. His r a the r bold asser t ions were evidence of h is inc reas ing tendency towards specula t ion character is t ic of his later years.

35. See Lovejoy, "Buffon and the Concept of Species," for a d iscuss ion of the n u m e r o u s opinions about Buffon's supposedly t r ans fo rma t ion i s t views. By avoiding this word we avoid fa lse analogies to Da r win ' s work.

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through selective breeding and change of envi ronment , one could reverse the trend towards greater var ia t ion and bring a var iety closer to the premier souche.

Although Buffon cont inued to use the labels of varidtd, esp~ce, and farnille, the words m e a n t different things. His fo rmer concept of species had been elevated to the p lane of a na tu ra l family, while the word esp~ce had been reduced to little more than a cons tan t variety. Since famil ies were composed of groups of con- s tant fo rms tha t normal ly did not interbreed, however, this change of mean i ng had little pract ical effect.

Buffon's sys tem allowed h im to explain m a n y of the problems he had earlier encountered in regard to the concept of species as well as to integrate the in format ion tha t he had on the geographical distr ibution of animals. Fertile mulets, for example , no longer presented an e m b a r r a s s m e n t for his breeding criterion. Since no crosses between an imals of different genera had been verified by Buffon, successful crossbreeding only s t rengthened his c la im of the genetic re la t ionship among m e m b e r s of the same family. Buffon's sys tem made sense of the similari ty of Nor th Amer ican f a u n a to European fauna . I f one assumed an ancient land bridge, then the present-day differences could be explained as the product of a long period of degenerat ion due to cl imatic and env i ronmenta l factors. Similarly, domest ic an imals could be easily related to wild forms, and the reductions tha t Buffon had previously wri t ten of concerning domest ic cattle and sheep no longer had to be considered exceptions imposed by m a n on the general course of nature. And lastly, fossils tha t resembled living animals were no longer a puzzle: they were the r emains of earlier representat ives of the species which lived at a different t ime and under different env i ronmenta l conditions.

We m a y consider Buffon's synthesis of 1766 as his mos t ma tu r e s t a tement about the living world, for it refiected the research of near ly thirty years on the quadrupeds and elegantly tied together all his published material . At the same time, we should not overlook the fac t that the sys tem was highly speculat ive and based on some very tenuous assumptions. For example , his central c la im tha t m e m b e r s of a fami ly could interbreed successfully with the premier souche--and this was a test of their ancest ra l l i n k - - h a d little empir ical backing. In 1766 Buffon knew of only a few cases of such crossbreeding, and even some of them were equivocal. The only ones he knew for sure were those of the horse and ass, the dog and wolf, the domest ic sheep, and the domest ic cattle.

This problem did not bother Buffon, for he was quite con-

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vinced of the t ruth of his system, and after 1766 he a t tempted to gather mater ia l to corroborate it. He continued his breeding exper iments and, mos t important ly , he began a study of the history of the ear th to furn ish an added dimension to his system.

The chapter "De la d~g6n~ration des animaux" raised m a n y questions for the person a t tempt ing to unders tand Buffon's concept of species. After 1766, when Buffon used the word esp~ce, he could be referr ing to either the premier souche and its direct morphological ly s imilar successions or to the lateral degenerat ions f rom the premier souche. Buffon still ma in ta ined tha t the moule int~rieur was a p e r m a n e n t impr in t that was constant in form. Time and the envi ronment , however, influenced its expression. For example , according to Buffon, the original moule, tha t is, the moule of the premier souche, with t ime could accumula te var ia t ions and eventually become as outwardly different as the wolf f rom the dog. Tha t their moules intdrieurs were basically the same, however, was demonstrable by their ability to breed together. A fami ly then was the collection of all l iving descendants of a premier souche.

In l ight of Buffon's theory of generat ion and the way in which his general theories developed af ter 1766, it m a y be s implest ff we consider the morphological ly s imilar succession of moules intdrieurs of the premier souche equivalent to the word "species," consider the degenerated lateral branches as "constant variations," and call the entire set an "extended species" or a "family." Buffon himsel f disdained questions of nomencla ture and did not revise wha t he had former ly called varieties, species and families, even though he had completely changed their meanings . 30

APPLICATION AND ELABORATION

Having completed the na tura l history of quadrupeds, Buffon applied his new and extended concept of species to a different set of da ta and went on to develop a complete system of na ture wi th the concept as one of its central ideas. The Histoire naturelle des oiseaux, which he began publishing in 1770, made use of the na tura l sys tem he had developed with the quadrupeds.

36. Buf fon p a r t i a l l y h i n t e d at t h i s c h a n g e d m e a n i n g i n h i s a r t i c l e on the v a r i e t i e s of the pe l i can . The case w a s s t a t ed m o r e s t r o n g l y i n a n ea r l i e r d r a f t of the a r t ic le , B ib l io th~que du M u s 6 u m n a t i o n a l d 'H i s to i r e n a t u r e l l e , MS. 739: " d a n s c h a q u e f a m i l l e de pe t i t s a n i m a u x , e t su r t ou t des pe t i t s o i seaux , i l y a u n e m u l t i t u d e de Races , p l u s ou m o i n s p roche P a r e n t e r , a u x que l l e s n o u s d o n n o n s i m p r o p r e m e n t Le no ra d 'Esp&ces; quo ique ce nora , e t l a n o t i o n M ~ t a p h y s i q u e qu ' l l r~n£erme, c o n v i e n n e b i e n m o i n s peut -e t re a L ' e s sence des choses e t ~ La v r a i e c o n n o i s s a n c e de L 'oeuvre de La N a t u r e , que c e u x de va r i e t e s , de Races , de f a m i l i e s . "

9.78


In i t he organized the birds by fami ly , tenta t ively s ingl ing out the premier souche and t rea t ing re la ted species as var ia t ions f rom the s tandard . In this way, Buffon was able to hand le the large n u m b e r of birds (over two thousand ) in a sys temat ic m a n n e r : 37

I believe, tha t I had to use a different p l an for the his tory of the birds f rom tha t which I set for mysel f and a t t empted to work out for the his tory of the quadrupeds . In place of t rea t ing the birds one by one, tha t is, by dis t inct species, I wil l combine several of them into a g e n u s . . , in this way, I have shor tened and reduced to a r a the r smal l space this his tory of the birds , which otherwise would have become too voluminous . . . re la ted species can be regarded as col la tera l b ranches of a common stem, so close to one another tha t one can assume a common souche and p resume tha t they or iginal ly came f rom this souche of which they still r e t a in a large n u m b e r of com- m o n character is t ics . These re la ted species were probably sep- a ra ted f rom one another by only the influences of the c l imate , of nut r i t ion , and by the passage of time. 3s

Buffon did not p re tend tha t his system for the bi rds was definitive. He real ized tha t at best i t was a sketch and hoped tha t i t would serve as a bas is for a fu ture complete na t u r a l h is tory of the birds. He was, however, convinced that the method tha t he had developed was the proper approach to a complete na tu r a l history, and this a t t i tude was reflected by his numerous a t t empts to de te rmine the premier souche of different famil ies . 39 In the art icle '~Le Coq" (vol. 2, 1771), for example , Buffon a t t empted to discover the re la t ionship of var ious breeds of chickens by col la t ing thei r degrees of fer t i l i ty in crossbreeding, and in the art icle '%e Serin" (vol. 4, 1778) he a t t empted to de te rmine f rom the da t a on hered i ta ry exper iments whe ther or not the ma le cont r ibuted a s t ronger influence upon the produc t of a crossbreeding.

Whi le he was employing his concept of an extended species to un i fy the s tudy of birds, Buffon was also a t t empt ing to cons t ruc t a system of na tu re wi th the concept as one of the cent ra l ideas. Al though he never publ i shed a separa te volume tha t brought

37. The general organization of Buffon's work, however, appears to rely heavily on the earlier work of Ray.

38. Histoire naturelle, Oiseaux, I (1770), xx. 39. As with the quadrupeds, Buffon believed that larger birds were less

subject to variation than smaller ones, and that therefore the premier souche was easier to establish.

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together all the diverse pieces of h is cosmology, 4° we c a n recon- s t ruc t his p ic ture of the cosmos by looking at a few art icles t h a t were p r in t ed af ter 1770. To the phys ica l world of b ru t e m a t t e r moved by u n i v e r s a l g rav i ta t ion , Buffon posi ted a second bas ic force i n n a t u r e : tha t of la chaleur. D u r i n g the ear ly h is tory of the ea r th it p layed no part . Buffon specula ted t ha t the ea r th was fo rmed as a resu l t of a comet s ideswip ing the sun , a n d tha t i t r e m a i n e d a m o l t e n glassy sphere w h i c h slowly cooled. 41 I n the Histoire natureUe des m i n d r a u x he t raced the evo lu t ion of the ea r th and the successive a p p e a r a n c e of mine ra l s . La te r i n "Des Epoques de la na tu r e " and other sect ions of the Supp ldmen t he descr ibed the g radua l geological p rogress ion of the ear th ' s surface. At first there h a d b e e n n o t h i n g except b ru t e mat te r . Af ter a great per iod of t ime, however , la chaleur, the second force i n na tu r e , pene t r a t ed par t ic les of b ru t e m a t t e r to f o r m moldcules organiques. These o rgan ic molecu les differed f r o m the i r a n t e c e d e n t s tate i n tha t they were self-active. 4e They were i m p o r t a n t d u r i n g the ear ly h is tory of the globe s ince the i r ac t ion was the cause of c rys ta l l i za t ion and the geometr ic s t ruc tu re of mine ra l s . 43 Occas ional ly some of these molecu les coalesced a nd f o r m e d an imal - l ike s t ruc tures . The resul t s were no t t rue an ima l s , for they did no t r ep roduce themselves . At a s o m e w h a t la ter stage, however , the o rgan ic molecu les came together wi th a smal l piece of w h a t Buffon cal led "ducti le ma t t e r " and s p o n t a n e o u s l y gave r ise to a moule intdrieur, which f r o m tha t po i n t on c o n t i n u e d to grow, develop, and reproduce i ts own kind. 44 Gradua l ly d i f ferent l i v ing fo rms popu la t ed the ear th , the fossil record ac t ing n o w as a h is tory of ear l ier changes.~5

Al though these occur rences were r a n d o m , the n e t resul t s were no t arbi t rary . Buffon bel ieved too m u c h i n the order l iness of

40. The closest he came to a full exposition was in the "Des Epoques de la nature," Histoire naturelle, Supplement, IV (1778).

41. Buffon performed elaborate experiments on the cooling of metal spheres to determine the age of the earth. In his published work he esti- mated that the age of the earth was 75,000 years old--quite a bit longer than o~thodox accounts, though not nearly as long as he really believed. Jacques Roger, in his critical edition of 'ODes Epoques de la natttre,'" Mdmoires du Musdum national d'Histoire naturelle, S6rie C, 10 (1962), published BuiTon's private manuscripts dating the earth almost three million years old.

42. Buffon's organic molecules were not like Leibniz' self-active points, in that there was a prior ontological distinction between matter and force.

43. H618ne Metzger, La Gen~se de la science des cristaux (Paris, 1918), discusses the importance of this notion in the history of crystallography.

44. Histoire naturelle, Mindraux, I (1783), 6. 45. In "Des Epoques de la Nature," Buffon roughly sketched out the

order of apearance of the major groups of animals.

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Nature to envision any sort of primeval chaos. His position was very clearly illustrated in a thought experiment he described. What ff God suddenly killed off all the animals on the earth, he speculated. What would happen? Since "Nature would always have the same quanti ty of life [organic molecules] one would see immediately the appearance of new species to replace the old ones." 4~ At first the new life forms would be larger due to the superabundance of organic molecules; however, the new beings would resemble the old ones, and after a sufficient length of time the world would more or less resemble its former state. 47

The moules int~rieurs, then, represented types of organization and emerged as a consequence of subjecting organic mat ter to certain initial conditions. Since Buffon believed that chemical properties could ultimately be explained in terms of universal gravitation working on brute matter, it may well be the case that he was carrying out his analogy between the physical and living worlds by conceiving of the moule intdrieur as a secondary affinity in the living world parallel to the chemical affinities in the physical world. 4s In such case, the moul e int6rieur was definitely on a lesser ontological plane.

This position partially resolved the problems earlier raised in regard to the moule int~rieur. It will be recalled that when Buffon described the replication of individuals, he wrote of the moule as if it owed its existence to the proper configuration of organic molecules. He thereby shed doubt on the authenticity of his claim that the moule int~rieur constituted a pr imary force in nature. By treating the moule intdrieur as an emergent organization of matter, Buffon circumscribed the problem in the sense that he no longer had to contend with the odd notion of a pr imary force duplicating. He was still left, of course, with the difficult task of explaining how individual moules intdrieurs reproduced. Since Buffon never revised his theory of generation we have no way of knowing how he would have dealt with the issue; his reformulat ion of the concept of the moule int~rieur at least removed some of the inconsistency inherent in his early hypothesis.

If Buffon's reformulat ion of the moule intdrieur avoided the

46. Histoire naturelleo Supplement, IV (1777), 358. 47. Ibid. 48. For a discussion of Buffon's chemical ideas, see Metzger, Newton,

Stahl, Boerhaave, and Maurice Crosland, "The Development of Chemistry in the Eighteenth Century," in Studies on Voltaire and the Eighteenth Century, 24 (1963), 369--441. Metzger and Crosland discuss the ways in which Btrffon's concepts were typical of the Newtonian interpretation of the mechanical philosophy.

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embarrassing problems of his 1749 account, it unfortunately raised new ones that were equally perplexing. Buffon originally spoke of the moule int~rieur as a force responsible for the internal and external form of each individual. By describing the moule int~rieur in his later writings as an emergent order in nature, he was treating the same concept as a natural kind. Buffon's ascription to the moule int~rieur of the dual role of representing individual form as well as the natural kind reflected a serious confusion on his part between the individual and the species.

Buffon's speculations on the ultimate foundations of the concept of species had evidently evolved since his philosophical discourses of the 1760's. In spite of some uncertainties concerning some of his concepts, he was able to construct a unified - - a lbe i t speculat ive--phi losophy for the biological sciences. The system was brilliant, and it was a landmark in man ' s rational investigation of the history of his environment.

THE SIGNIFICANCE OF BUFFON'S CONCEPT OF SPECIES

Buffon's concept of species attained widespread popularity during the eighteenth century. The well known Dictionnaire de Tr~voux as well as the Encyclopedic of Diderot and D'Alembert, for example, gave verbatim quotations of Buffon's formulat ion as their definitions of animal species. Any contemporary account of species in the biological sense had to recognize Buffon's work in one way or the other. Having looked at the development of Buffon's thought in the above pages, we may now pass on to consider why it was that Buffon's t reatment became so important.

For one thing, the Histoire naturelle was the most widely read book on natural history in France and was the third most popular piece of literature during the latter part of the century. 49 Its elevated style of writing and its broad scope led m a n y to accept Buffon's encyclopedia of nature as definitive, and even in trans- lation it was enormously popular well into the nineteenth century, no Moreover, in France, Buffon was highly placed and dominated the Jardin du Roi, then the largest and most important institution for teaching and research in biology. The prestige and respect that he consequently commanded is not to be underestimated. It would be erroneous, however, to conclude that Buffon's concept of species was popular solely for extraneous

49. Daniel Mornet, "'Les Ensc ignemen t s des biblioth~ques pr iv ies (1750- 1780)," Revue d'histoire litt$raire de la France, 17 (1910), 460.

50. Mine. E. Genet-Vaxcin and Jacques Roger, eds., "Bibliographie de Buffon," i n O.P., h a s a l ist of the n u m e r o u s f o r e i g n editions.

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reasons. Tha t his wr i t ings were widely read and his f ame un- quest ioned gave added weight to his opinions. Nonetheless , he was quoted for the value of his thought. Dur ing the Enl ighten- men t Bui~on's wri t ings on species represented an or iginal at- t empt to redefine the not ion in keeping wi th new at t i tudes and

beliefs. The phi losophers waged an extended c a m p a i g n dur ing the

e ighteenth cen tury in their a t t empt to change m a n ' s th ink ing and to improve man ' s lot. "~I Their bat t les were fought on all f ronts : law, moral i ty , ethics, art, l i tera ture , physics , and na t u r a l history. Since s tudents of the En l igh tenmen t have concent ra ted largely on the legal and l i te rary aspects of the philosophes" program, Buffon and other na tu ra l i s t s have often been over- looked. However, Buffon's popular i ty in his own day suggests tha t his contemporar ies apprec ia ted his role bet ter t han posteri ty. On a popula r level, Buffon's concept of species and cosmology provided a viable a l te rna te to the Genesis account of the origin and his tory of the world. The total ly secular na tu re of his work was great ly apprec ia ted by the m e n who were l aunch ing a full- scale a t tack on t rad i t iona l or thodoxy in Europe. Buffon's his tory of an ima l forms was independen t of Scripture, as was the deve lopment of the surface of our planet , an aspect of his work tha t was heavi ly cri t icized by theologians.

On a more phi losophical p lane , Buffon's t r ea tmen t of species reflects the theoret ica l biases of the age. One m a y ra ise serious logical object ions to the a im of cons t ruc t ing a scientific base for the biological sciences analogous to Newton ian physics; however, the a t t empt discloses the enormous influence of the new Engl ish science on the phi losophes, and i t was indica t ive of the numerous a t tempts to pick up Newton 's man t l e in different areas of invest igat ion. 52 Buffon's stress on the m o u l e i n t d r i e u r

51. There are several major interpretations of the break that the philosophes made with their Christian background. See for example; Paul Hazard, European Thought in the Eighteenth Century (New York, 1967); Daniel Morner, Les Origines intelleet~uelles de la r~volution frangaise 1715--1787 (Paris, 1967); Ernst Cassirer, The Philosophy of the Enlighten- m e n t (Princeton, 1951); Carl L. Becket, The Heavenly City of the Eighteenth- Century Philosophers (New Haven, 1962); Lester Crocker, A n Age of Crisis (Baltimore, 1959); and Peter Gay, The Enl ightenment: An Interpreta- t ion (New York, 1966).

52. Newton's influence on the philosophes has often been noted and discussed. Recently Peter Gay, The Enl ightenment , has written very clearly on Newton and his relationship to the philosophes, particularly on the many attempts of the philosophes to do '2~/ewtonian" investigations in areas other than physics. See also Gerd Buchdahl, The Image of Newton and Locl~e in the Age of Reason (London, 1961).

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and his use of breeding criterion for establishing species mem- bership, in addition to giving h im the r ight to be considered the Newton of biology, de-emphasized ana tomy and consequently opened up the possibility of considering species in te rms other than wholly morphological ones. Drawing on informat ion f rom the New World concerning geology and the degenerat ion of animals , and employing one of the s tandard modes of inquiry among the philosophes, Buffon treated species as a historical entity, one tha t was in t imate ly related to the development of the ear th 's surface, and one that had undergone significant modifica- t ion due to the changing environment . A species, therefore, was not a static category. I t was a succession of genetically related beings that differentiated in time. Buffon pointed out tha t since the env i ronment was the cause of its changing expression, the concept of species was inextr icably associated with the history of the earth, zoogeology, and zoogeography. This shif t of emphasis f rom contemplat ion of fo rm to an inquiry into the physical na ture of species and its in teract ion with the mutab le env i ronment m a d e possible an entirely new set of questions regarding the relat ionship between species and their milieu as well as their na tu ra l origin. The history of n ineteenth-century biology attests to the f rui t fulness of this approach.

Buffon's concept of species deserves the at tent ion of his tor ians a t tempt ing to synthesize an intel lectual history of the eighteenth century as well as those interested in late eighteenth- and early nineteenth-century na tu ra l history. In impor tan t aspects Buffon's ideas were par t of the Enl igh tenment and served to condition an entire generat ion 's percept ion of the living world.

Acknowledgements

The research for this paper was begun while I was a graduate s tudent in the Depa r tmen t of the History and Philosophy of Science at Ind iana University. I wish to express m y thanks to Professor Frederick B. Churchill , who directed m y Ph.D. dis- sertation, and to the Josiah Macy, Jr. Foundat ion for its generous support. I am also indebted to the assistants in the reading room of the Biblioth~que centrale du Mus6um nat ional d 'Histoire naturelle, and to the l ibrar ians of the Archives de l 'Acad~mie des Sciences for their at tentive help.

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