On the Heuristic Value of Hans Driesch’s Vitalism

AbstractIn the first half of the twentieth century the harshest critics of Hans Driesch’s vitalistic theory depicted it as an animistic view driven by metaphysical moods, while others merely saw it as a barren hypothesis. In the last decades the heuristic value of vitalistic principles was nevertheless suggested. In this chapter I examine the epistemic role of Driesch’s critical vitalism in the progress of embryology. I first show that it did not contribute to falsify mechanical explanations of development such as Wilhelm Roux’s mosaic theory and Driesch’s own embryonic induction model. However, Driesch’s argumentation for vitalism led to the final formulation of the most challenging developmentalexplanandumof the twentieth century: the harmonious-equipotential system (HES). I point out how majorexplananslike Charles M. Child’s metabolic gradients, Hans Spemann’s induction fields and Lewis Wolpert’s positional information were conceived as promising answers to Driesch’s problem.