Leibniz often refers to the Principle of Sufficient Reason (PSR) as something like a first principle. In some texts, however, he attempts to give positive arguments in its favor. I examine two such arguments, and find them wanting. The first argument has two defects. First, it is question-begging; and second, when the question-begging step is excised, the principle one can in fact derive is highly counter-intuitive. The second argument is valid, but has the defect of only reaching a nearly trivial (...) conclusion. (shrink)

This book presents an in-depth interpretation of three important parts of Leibniz's metaphysics: the metaphysical part of Leibniz's philosophy of logic, his essentially theological treatment of the central issues of ontology, and his theory of substance.

It can be shown by means of a paradox that, given the Principle of Sufficient Reason, there is no conjunction of all contingent truths. The question is, or ought to be, how to interpret that result: _Quid sibi velit?_ A celebrated argument against PSR due to Peter van Inwagen and Jonathan Bennett in effect interprets the result to mean that PSR entails that there are no contingent truths. But reflection on parallels in philosophy of mathematics shows it can equally be (...) interpreted either as a proof that there are "too many" contingent truths to combine in a single conjunction or as a proof that the concept _contingent truth_ is indefinitely extensible and there is no such thing as "all contingent truths." Either interpretation would reconcile PSR with contingent truth, but the natural rationales of those interpretations are at odds. This essay argues that the second interpretation is a more satisfactory explanation of why, if PSR is true, there should be no conjunction of all contingent truths. This sheds new light on the nature of the explanatory demand embedded in PSR and uncovers a number of surprising implications for the commitments of rationalism. (shrink)

The aim of this paper is to trace in Leibniz’s drafts the sketched outline of a conceptual framework he organized around the key concept of ‘requisite’. We are faced with the project of a semi-formal theory of conditions, whose logical skeleton can have a lot of different interpretations. In particular, it is well suited to capture some crucial relations of ontological dependence. Firstly the area of ‘mediate requisites’ is explored - where causal and temporal relations are dealt with on the (...) basis of a general theory of ‘consequence’.Then the study of ‘immediate requisites’ is taken into account - a true sample of mereological inquiry, where Leibniz strives for a unitary treatment of part-whole relation, conceptual inclusion and inherence. Far from simply conflating these relations one with another and with causality, therefore, Leibniz tried to spell them out, while at the same time understanding them within a single conceptual framework. (shrink)

"This is an important book, and no one interested in issues which touch on the free will will want to ignore it."--Ethics. In this stimulating and thought-provoking book, the author defends the thesis that free will is incompatible with determinism. He disputes the view that determinism is necessary for moral responsbility. Finding no good reason for accepting determinism, but believing moral responsiblity to be indubitable, he concludes that determinism should be rejected.

This paper critically examines a prominent and perennial strategy—found in thinkers as diverse as Kant and Shamik Dasgupta—of simultaneously embracing the Principle of Sufficient Reason and also limiting it so as to avoid certain apparently negative consequences of an unrestricted PSR. I will argue that this strategy of taming the PSR faces significant challenges and may even be incoherent. And for my purposes, I will enlist a generally derided argument by Leibniz for the PSR which will help us to see (...) the connections between the PSR and a radical form of monism. (shrink)

Peter van Inwagen presented a powerful argument against the Principle of Sufficient Reason, which I henceforth abbreviate as ‘PSR’. For decades, the consensus was that this argument successfully refuted PSR. However, now a growing consensus holds that van Inwagen’s argument is fatally flawed, at least when ‘sufficient reason’ is understood in terms of ground, for on this understanding, an ineliminable premiss of van Inwagen’s argument is demonstrably false and cannot be repaired. I will argue that this growing consensus is mistaken (...) and that a powerful argument relevantly similar to van Inwagen’s should still concern us, even when we understand ‘sufficient reason’ in terms of ground. (shrink)

This volume contains papers that represent Leibniz’s early thoughts on the problem of evil, centering on a dialogue, the Confessio philosophi, in which he formulates a general account of God’s relation to sin and evil that becomes a fixture in his thinking. How can God be understood to be the ultimate cause, asks Leibniz, without God being considered as the author of sin, a conclusion incompatible with God’s holiness? Leibniz’s attempts to justify the way of God to humans lead him (...) to deep discussion of related topics: the nature of free choice, the problems of necessitarianism and fatalism, the nature of divine justice and holiness. All but one of the writings presented here are available in English for the first time. (shrink)

This essay examines arguments offered in support of the Principle of Sufficient Reason (PSR) by Leibniz and his followers as well as Hume's critique of the PSR. It is shown that Leibniz has a defensible argument for the PSR, whereas the arguments of his self-proclaimed followers are weak. Thus, Hume's challenge is met by Leibniz, by Wolff and Baumgarten not so much.