Enjeux métaphysiques de la morphogenèse : l’embryologie de Ruyer et la biologie du développement

Biology holds a special place in Raymond Ruyer’s philosophy. This paper focuses on several biological facts considered by Ruyer as being of essential metaphysical interest. Its aim is to inquire if recent discoveries in developmental biology may invalidate his most important arguments concerning morphogenesis, i.e., the apparition of a new form in the development of the embryo, and especially his rejection of mechanistic explanations. Three groups of facts are examined: the role of genes in embryonic development and the necessity for non-genetic factors; the multiscale coordination of development (leading to problems such as cell positional information or the theory of a morphogenetical field); the requirement for a form of downward causality, which goes from the organism towards the genome. This study is primarily intended to emphasize the persistence of important philosophical questions concerning morphogenesis, and the interest of Ruyer’s specific approach in understanding those questions.