Leibniz's principle of sufficient reason is the claim that everything has a sufficient reason. But is Leibniz committed to the necessity or to the contingency of his great principle? I argue that Leibniz is committed to its contingency, given that he allows for the absolute possibility of entities that he claims violate the PSR. These are all cases of qualitatively indiscernible entities, such as indiscernible atoms, vacua, and bodies. However, Leibniz's commitment to the contingency of the PSR seems to stand (...) in tension with his inference of the PSR from his theory of truth. I argue that this apparent tension can be resolved satisfactorily. When it comes to his modal views on the PSR, Leibniz's position is entirely consistent. (shrink)

I examine several alleged grounds of the principle of sufficient reason in Leibniz’s philosophy. These include the nature of a requisite and a sufficient condition, the nature of truth, and the nature of harmony. I argue that Leibniz does not ground the PSR in any of these ways. Instead, he is committed to a value-based grounds of the PSR: God creates the best possible world, and the fact that the PSR obtains in this world contributes to it being the best. (...) I conclude by considering some objections to this way of grounding the PSR. (shrink)

According to a common reading, Spinoza and Leibniz stand on opposite ends of the modal spectrum. At one extreme lies ‘‘Spinoza the necessitarian,’’ for whom the actual world is the only possible world. At the other lies ‘‘Leibniz the anti-necessitarian,’’ for whom the actual world is but one possible world among an infinite array of other possible worlds; the actual world is privileged for existence only in virtue of a free decree of a benevolent God. In this paper, I challenge (...) both of these readings. Spinoza is no necessitarian and Leibniz is no anti-necessitarian – at least as these characterizations are usually understood. Rather, I contend, Spinoza and Leibniz are both anti-essentialists; they believe that the modality of objects can vary relative to how those objects are conceived. This shared commitment to anti-essentialism allows them to consistently affirm both necessitarianism and its denial, relative to different ways of conceiving the world. Their embrace of this modal theory, I further argue, is grounded in their similar views on metaphysical perfection, ontological plentitude, and the principle of sufficient reason. (shrink)

Leibniz is commonly labeled a foe of Molinism. His rejection of robust libertarian freedom coupled with some explicit passages in which he distances himself from the doctrine of middle knowledge seem to justify this classification. In this paper, I argue that this standard view is not quite correct. I identify the two substantive tenets of Molinism. First, the connection between the conditions for free actions and these free actions is a contingent one: free actions follow contingently from their sufficient conditions. (...) Second, God knows what creatures would freely do in different possible circumstances prevolitionally—that is, prior to God willing anything. I argue that Leibniz himself endorses a version of both tenets and utilizes them for theoretical purposes similar to those of Molinists. I conclude that Leibniz is much closer to Molinism than is typically acknowledged. Leibniz is best characterized as a friend—rather than a foe—of Molinism. (shrink)

This dissertation examines Locke's and Leibniz' explanation of the origin and nature of the world. As Leibniz writes in his "De Rerum Originatione Radicali," which is used as a guide to the issues addressed, this project involves answering two questions: "Why is there a world at all?" and "Why is the world the way it is?" Both Leibniz and Locke answer the first question by way of a cosmological argument for the existence of God as the first cause of the (...) world. I explicate and criticize these arguments. I also examine the metaphysical and theological presuppositions of the arguments. Leibniz's and Locke's views on the structure and intelligibility of the world answer the second question. (shrink)