Jean Gayon

Dans la théorie contemporaine de l’évolution, trois sens classiques de la notion de hasard interviennent : la notion ordinaire de chance, la notion probabiliste de l’aléatoire, et la notion épistémologique de contingence relativement à un système théorique. Ces trois notions suffisent à définir le statut du hasard aux principaux niveaux du processus évolutif où l’on invoque communément des effets fortuits : mutations, dérive génétique, révolutions génétiques, changements écologiques, macroévolution. On se demande enfin si les divers sens du hasard rencontrés dans cette étude peuvent être ramenés à l’unité, et s’ils renvoient à un hasard subjectif ou à un hasard objectif. In the contemporary theory of evolution, three classical meanings of the notion of chance come into play : the ordinary meaning of chance, the probabilistic notion of randomness, and the epistemological notion of contingency with reference to a theoretical system. These three notions are sufficient in order to define the status of chance on the principal levels of the evolutive process where fortuitous effects are commonly invoked : mutations, genetic deviations, genetic revolutions, ecological changes, macroevolution. The question is raised, finally, whether the diverse meanings of chance considered in the present study may be brought to one, and whether they refer to a subjective form of chance or to an objective chance.

Did Darwin Write the Origin Backwards is Sober’s book that comes closest to history of science. Some reviews have expressed reservations about Sober’s inclination to subordinate historical accuracy to analytical clarity, and to contemporary discussions . My comments will be devoted to the kind of relationship that Sober entertains with history of science. I do not think that the author’s interest in history is superficial and instrumental.In the first section, I try to locate Sober’s book within ‘&HPS’ , a recent initiative that gathers a growing number of people willing to promote a new regime of interaction between philosophy and history of science. I will suggest that Sober offers an interesting way of developing this approach. The more critical second section is devoted to Sober’s first chapter, bearing on the relationship between the two main tenets of Darwin’s argument in the Origin—descent with modif ..

In Darwinism's Struggle for Survival Jean Gayon offers a philosophical interpretation of the history of theoretical Darwinism. He begins by examining the different forms taken by the hypothesis of natural selection in the nineteenth century and the major difficulties which it encountered, particularly with regard to its compatibility with the theory of heredity. He then shows how these difficulties were overcome during the seventy years which followed the publication of Darwin's Origin of Species, and he concludes by analysing the major features of the genetic theory of natural selection, as it developed from 1920 to 1960. This rich and wide-ranging study will appeal to philosophers and historians of science and to evolutionary biologists

Les questions que le philosophe peut aujourd'hui se poser sur l'évolution sont de deux ordres. Les unes relèvent de la philosophic des sciences (de quel genre de science s'agit-il ?). Les autres regardent la philosophic en général: dans quelle mesure l'évolution conduit-elle à réexaminer certaines grandes questions philosophiques traditionnelles, comme celles des fondements de l'épistémologie (théorie de la connaissance) et de l'éthique ? The questions a philosopher may raise today about evolution are twofold : on the one hand they may refer to the philosophy of science (what kind of a science is it ?). On the other hand, they may refer to philosophy as such : in what way does evolution lead one to reexamine a few traditional philosophical question as that of the foundations of epistemology (a theory of knowledge) and ethics ?

Literally speaking, "Philosophy of biology" is a rather old expression. William Whewell coined it in 1840, at the very time he introduced the expression "philosophy of science". Whewell was fond of creating neologisms, like Auguste Comte, his French counterpart in the field of the philosophical reflection about science. Historians of science know that a few years earlier, in 1834, Whewell had generated a small scandal when he proposed the word "scientist" as a general term by which "the students of the knowledge of the material world" could describe themselves, and distinguish themselves from artists. The term "philosopher", Whewell argued, was too wide. A new generic term, more or less equivalent to the French term "savant", was needed in order to prevent the disintegration of science that seemed to flow from its specialization in modern times.1 When Whewell first introduced the terms "philosophy of science" and "philosophy of biology" in his 1840 Philosophy of the inductive sciences, the latter term was merely a special branch of "philosophy of science". The expression "philosophy of science" itself had two justifications: firstly, this phrase expressed the idea that "science" remained cognitively coherent enough to justify a critical enquiry into its methodological unity and its foundation; secondly, the phrase "philosophy of science" was required in order to distinguish a properly "philosophical" enquiry from a "historical" approach to science. Although Whewell's 1840 Philosophy of the inductive sciences 2 had approximately the same chapter structure as his 1837 History of the Inductive Sciences 3 (that is, a series of chapters successively devoted to the concept of science in general, and although there was considerable overlap between the contents of the two books, then to particular sciences), its theoretical purpose was different. Clearly, Whewell was not willing to confuse the genres of history and philosophy as Auguste Comte had done in his 1830 Cours de philosophie positive.4 Note also that the word "biology" was still extremely rare in English when Whewell used it in 1840. In fact, Whewell's 1837 History of the Inductive Sciences does not make use of the word "biology": Whewell successively examines "botany", "zoology", "physiology" and "comparative antomy" as special branches of "analytico-classificatory science", then discusses palaeontology as a special case of the "palaeo-etiological sciences". Three years later, in his Philosophy of the Inductive Sciences, Whewell does use "biology" as a generic term for all the sciences dealing with life. The various sciences which were separately examined in the previous book are now collectively considered. Furthermore, the main philosophical problem raised by biology is its dual nature: biology is both nomological and a historical science. Modern philosophers of biology are generally unaware of the story of the origins of the expression "philosophy of biology", but Whewell's dual theoretical nature of biology is still a major concern for modern "philosophy of biology"

Omniprésente dans l'ensemble des sciences de la vie, la catégorie de fonction a les allures d'un scandale épistémologique : attribuer une fonction à une structure ou à un processus biologique, c'est en effet suggérer qu'on l'explique par ses effets. Cet ouvrage, sans précédent en langue française examine les débats philosophiques contemporains sur les fonctions depuis une trentaine d'années, et propose de nouvelles voies d'analyse. Il confronte ces débats à l'usage de la notion de fonction dans un large spectre de disciplines biologiques, psychologiques et médicales. Il soulève aussi la question de savoir si cette notion, aussi ancienne dans l'histoire des techniques que dans celle des sciences de la vie, y a le même sens.

The article examines two cases of adoption of evolutionary ways of thinking by modern economists: Nelson and Winter’s (Evolutionary Theory of Economic Change, 1982), and evolutionary game theory (1990s and after). In both cases, the authors explicitly refer to natural selection in an economic context. I show that natural selection is taken in two different senses, which correspond to two general conceptions of the principle of natural selection, one of which contains reproduction and heredity as key elements, whereas the other does not.

Since the 1970s, there has been a tremendous amount of literature on Ghiselin's proposal that species are individuals. After recalling the origins and stakes of this thesis in contemporary evolutionary theory, I show that it can also be found in the writings of the French naturalist Buffon in the 18th Century. Although Buffon did not have the conception that one species could be derived from another, there is an interesting similarity between the modern argument and that of Buffon regarding the individuality of species. The analogy is strong enough to force us to recognize that genuine evolutionary (or Darwinian) questions might be of secondary importance in the discussion. In consequence, the third section of the paper proposes an alternative schema for the logical structure of the Darwinian concept of species. Darwin distinguished the problem of the designation of a concrete species, and the problem of its signification of species within his theory of descent? The resulting notion of species involves a logical structure based on the fusion of the logical operations of classification and ordering. The difficulty — and interest — is that this interpretation of species does not entail any precise operational definition of species; it can only tell us what the ultimate signification of classification is within the theory of descent with modification through natural selection.

In Darwinism's Struggle for Survival Jean Gayon offers a philosophical interpretation of the history of theoretical Darwinism. He begins by examining the different forms taken by the hypothesis of natural selection in the nineteenth century and the major difficulties which it encountered, particularly with regard to its compatibility with the theory of heredity. He then shows how these difficulties were overcome during the seventy years which followed the publication of Darwin's Origin of Species, and he concludes by analysing the major features of the genetic theory of natural selection, as it developed from 1920 to 1960. This rich and wide-ranging study will appeal to philosophers and historians of science and to evolutionary biologists.

Chance comes into plays at many levels of the explanation of the evolutionary process; but the unity of sense of this category is problematic. The purpose of this talk is to clarify the meaning of chance at various levels in evolutionary theory: mutations, genetic drift, genetic revolutions, ecosystems, macroevolution. Three main concepts of chance are found at these various levels: luck (popular concept), randomness (probabilistic concept), and contingency relative to a given theoretical system (epistemological concept). After identifying which concept(s) of chance fit(s) with these levels, the question is raised whether these concepts can be reduced to a smaller number, and whether chance in evolutionary theory has a subjective or an objective sense