This work investigates the fundamental epistemological divergence between Leibniz and Descartes regarding the nature of mathematical proof and the status of eternal truths. Ian Hacking, a prominent philosopher of science, utilizes a comparative analysis of these two thinkers to examine how their respective doctrines on necessity and contingency shaped early modern philosophy. By situating their arguments within the context of geometrical and algebraic development, Hacking provides a rigorous framework for understanding the transition from classical to modern mathematical thought.

Experts recognize this lecture as a concise yet highly dense contribution to the study of early modern rationalism. Readers frequently note the academic rigor of the prose, which serves as a foundational text for those interested in the intersection of mathematical history and philosophy.