My current research focuses on the philosophy of Leibniz, particularly concerning the principle of sufficient reason. Here are some abstracts:
Leibniz is known for his principle of sufficient reason (PSR), the claim that everything has a complete explanation. But what, according to Leibniz, grounds the PSR itself? While it is generally thought that Leibniz grounds the PSR in his logic, I argue that Leibniz grounds the PSR in his theodicy. God creates the best possible world, and a world in which the PSR is true is better than a world in which it is false. I also examine three other alleged grounds of Leibniz’s PSR. These include the nature of necessary and sufficient conditions, the nature of truth, and the world’s harmony. I argue that these alleged grounds, though not without their merits, are ultimately unsatisfactory as grounds of Leibniz’s PSR. I then conclude by suggesting a new way of understanding the relation between the PSR and another one of Leibniz’s principles, namely the principle of the best.
Leibniz’s principle of sufficient reason (PSR) is the claim that everything has an explanation. 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 atoms, vacua, and indiscernible bodies. However, Leibniz’s commitment to the contingency of the PSR seems to stand in tension with some of his other modal commitments. These include his inference of the PSR from the concepts of a requisite and a sufficient reason, his inference of the PSR from his theory of truth, and his claim that something very much like the PSR is absolutely necessary. I argue, however, that these apparent tensions can be satisfactorily resolved. When it comes to his modal views on the PSR, Leibniz’s position is entirely consistent.
Rethinking Leibniz’s cosmological argument
Leibniz’s cosmological argument for the existence of God appears to be very straightforward: no matter how far back we go in the series of contingent beings, a sufficient reason for the existence of the entire series cannot be found in the series itself; we must therefore appeal to a being outside the series, which will necessarily exist and is ultimately identified as God. What is not straightforward, however, is what exactly God is supposed to explain. I consider three possible interpretations. On the mereological interpretation, God explains why the whole series exists, where the whole is something over and above its parts. On the modal interpretation, God explains why the series is possible. And on the contrastive interpretation, God explains why this series exists rather than another. I argue that the mereological and modal interpretations fail, and that the contrastive interpretation is correct.