Alain Prochiantz invites us here to join him in a wonderful exploration of a new field of modern science: the biology of development. Based on the most recent scientific discoveries, but also on the work of scientists such as Geoffroy Saint-Hilaire, Darwin, Haeckel and even Goethe, he defends with both passion and rigor a romantic concept of the unity of Nature as opposed to the positivist dogma which considers the brain as a machine. Indeed, the discovery of the genes of development has permitted the expression of a biological theory finally liberated from the models and systems of logics generally derived from physical mathematics.But this discovery, which makes it possible to produce new animal or plant forms, and to bring back to life older forms, also shows that the science of evolution has reached a new age, that of experimentation. This will undoubtedly have important consequences in the medical and economical fields.

Alain Prochiantz is director of the Laboratory for the development and evolution of the nervous system at the Ecole normale supérieure. He is the author of Stratégies de l'embryon and La Biologie dans le boudoir.