This paper offers a defense of a much-maligned Leibnizian argument for the Principle of Sufficient Reason, the principle according to which whatever is has a sufficient reason or explanation. While Leibniz’s argument is widely thought to rely on a question-begging premise, the paper offers a wholly original and non-question-begging defense of that premise, a defense that Leibniz did not anticipate. The paper does not present this defense of Leibniz's argument as an interpretation of Leibniz; rather, the paper—more modestly in one (...) way, less modestly in another—simply claims that this argument succeeds. (shrink)

For Émilie Du Châtelet, I argue, a central role of the principle of sufficient reason is to discriminate between better and worse explanations. Her principle of sufficient reason does not play this role for just any conceivable intellect: it specifically enables understanding for minds like ours. She develops this idea in terms of two criteria for the success of our explanations: “understanding how” and “understanding why.” These criteria can respectively be connected to the determinateness and contrastivity of explanations. The crucial (...) role Du Châtelet’s principle of sufficient reason plays in identifying good explanations is often overlooked in the literature, or else run together with questions about the justification and likelihood of explanations. An auxiliary goal of the article is to situate Du Châtelet’s principle of sufficient reason with respect to some of the general epistemological and metaphysical commitments of her Institutions de Physique, clarifying how it fits into the broader project of that work. (shrink)

The Principle of Sufficient Reason is a powerful and controversial philosophical principle stipulating that everything must have a reason or cause. This simple demand for thoroughgoing intelligibility yields some of the boldest and most challenging theses in the history of metaphysics and epistemology. In this entry we begin with explaining the Principle, and then turn to the history of the debates around it. A section on recent discussions of the Principle will be added in the near future.