Leibniz on Natural Teleology and the Laws of Optics

Abstract

This essay examines one of the cornerstones of Leibniz’s defense of teleology within the order of nature, namely, his derivation of the two central laws of geometrical optics from his “Most Determined Path Principle” or “MDPP”. The first section places the MDPP in its historical context, and argues that it allows Leibniz to bring to the fore philosophical issues concerning the legitimacy of teleological explanations by addressing two technical objections raised by Cartesians to non-mechanistic derivations of the laws of optics. The second section argues that, by drawing on laws such as the MDPP, Leibniz is able to introduce a thin notion of teleology that gives him the resources to respond to the most pressing charges of his day by showing how teleology within the order of nature may be stripped of problematic Scholastic commitments, fitted to accepted explanatory structures, and successfully applied to a wide and promising range of natural phenomena. Finally, the third section argues that contemporary philosophers have been overly hasty in their dismissal of Leibniz’s account of natural teleology, and indeed that their own generally thin conceptions of teleology have left them with few well-motivated resources for resisting Leibniz’s elegant position.