Jeffrey McDonough

This essay explores Leibniz's defense of teleology and teleological explanations in the domain of physics in general, and the roles that teleology plays in his studies of optics in particular. I argue first that Leibniz draws upon Plato's defense of final causes to introduce a novel research program intended to steer a middle course, on the one hand, between Aristotelian-Scholasticism and the new mechanical philosophy, and, on the other hand, between Cartesian rationalism and Gassendist empiricism. The implementation of this program leads Leibniz to significant conceptual innovations, as he attempts to reconcile teleological and efficient explanatory frameworks, and important discoveries, as he tries to show how final causes can be used to achieve results in the study of the natural world. ;Having situated Leibniz's defense of final causes in the broader context of his general philosophy of physics, I turn to a more detailed investigation of the roles that teleology plays in his work in geometrical optics. Interest in final causes leads Leibniz to introduce his "Most Determined Path Principle" from which both of the central laws of geometrical optics may be derived. I argue that Leibniz uses the discovery of such principles to introduce a thin notion of final causation within the order of nature based on teleological laws that link prior events to subsequent events via the likely or expected outcomes of those events, and defend this view against objections made both by Leibniz's contemporaries and our own. I also argue that Leibniz uses the discovery of principles like Most Determined Path Principle to provide a novel connection within his system between considerations of divine perfection and the laws of nature. I defend the internal consistency of this connection, and explore its relations to Leibniz's mature physics, and to his view that the world is governed by two sets of equipotent laws, one teleological and one mechanical

In his rich and engaging essay, Professor Garber asks most centrally, “…what was the relation between Leibniz’s metaphysical project as set out in the so-called ‘Monadologie’ and the more theological project in the Essais de Théodicée?” His answer is, in short, that there isn’t much of a relationship between these two great works. Furthermore, he takes this result to be evidence of Leibniz’s not being a systematic philosopher in the spirit of Descartes or Spinoza. In these brief comments, I revisit Garber’s two central questions in turn and offer some moderating resistance to both of his conclusions.

entry for the Stanford Encyclopedia of Philosophy (SEP) This entry will attempt to provide a broad overview of the central themes of Leibniz’s philosophy of physics, as well as an introduction to some of the principal arguments and argumentative strategies he used to defend his positions. It tentatively includes sections entitled, The Historical Development of Leibniz’s Physics, Leibniz on Matter, Leibniz’s Dynamics, Leibniz on the Laws of Motion, Leibniz on Space and Time. A bibliography arranged by topic is also included. A working draft is available here (comments, as always welcome): draft.

This essay attempts to provide a sympathetic reading of Hume’s often tangled discussion of memory in the Treatise. It divides into three main sections. The first section isolates three puzzles in Hume’s account of memory. The second section attempts to show how those puzzles arise as a result of Hume’s understandable failure to recognize a necessary connection between memory and causation. Finally, the third section looks at how the reading of Hume’s account of memory offered in the first two sections fits into the larger context of his work by considering the roles he assigns to memory in his famous account of personal identity.

The following paper attempts to explore, criticizeand develop Thomas Kuhn's mostmature – and surprisingly neglected – view ofincommensurability. More specifically, itfocuses on (1) undermining an influential picture ofscientific kinds that lies at the heartof Kuhn's understanding of taxonomic incommensurability;(2) sketching an alternativepicture of scientific kinds that takes advantage ofKuhn's partially developed theory ofdisciplinary matrices; and (3) using these two resultsto motivate revisions to Kuhn'stheory of taxonomic incompatibility, as well as, tothe purported bridge betweentaxonomic incompatibility and some of the traditionalproblems associated withincommensurability.

This essay offers an alternative account of Leibniz’s views on substance and fundamental ontology. The proposal is driven by three main ideas. First, that Leibniz’s treatment should be understood against the backdrop of a traditional dispute over the paradigmatic nature substance as well as his own overarching conciliatory ambitions. Second, that Leibniz’s metaphysics is intended to support his conciliatory view that both traditional views of substance are tenable in at least their positive and philosophical respects. Third, that the relationship between immaterial substances, corporeal substances, and ordinary bodies in Leibniz’s metaphysics is best understood as one of “material” constitution. The interpretation as a whole thus suggests that Leibniz needn’t be read as offering either an exclusive defense of corporeal substance realism, nor of immaterial substance idealism, nor as being deeply torn (at a time or over time) between two such views. He may instead be seen as offering a carefully presented, consistent, and sophisticated conciliatory account of substance

Daniel Garber’s Leibniz: Body, Substance and Monad . When I first entered graduate school Dan’s previous book Descartes’s Metaphysical Physics had recently appeared, and it made a huge and lasting impression on me. All of a sudden I saw Descartes’s project in a much different, more intriguing light. This Garber fella had managed to open up a new area of Descartes’s thought to me, to tease out with great care his philosophical arguments, and to situate both in a broader historical context in which they seemed to me at least much more at home. In short, Dan’s Descartes’s book is one of the main reasons why I work on Leibniz. And now we have his rich, learned, and provocative book on Leibniz to wrestle with. I am certain that it will similarly inspire another generation of early modern scholars as well – hopefully they won’t all be moved to work on Kant!

In a stimulating recent paper, “Violations of the Principle of Sufficient Reason (in Leibniz and Spinoza),” Michael Della Rocca argues that rationalists face a daunting dilemma: either abandon the Principle of Sufficient Reason or embrace a radical, Parmenidian-style monism. The present paper argues that neither historical nor contemporary rationalists need be afraid of Della Rocca’s dilemma. The second section reconstructs Della Rocca’s argument in five steps. The third section argues that Leibniz’s treatment of relations undermines one of those steps in particular and thus provides him—as well as contemporary rationalists—with a way out. The fourth section argues that a similar way out is available to Spinoza, and that it’s a better way out than either of the two options Della Rocca offers on Spinoza’s behalf. The essay concludes with an historically-minded suggestion for those eager to revitalize the once-again popular notion of grounding.

Confronting the threat of a Spinozistic necessitarianism, Leibniz insists that not all possible substances are compossible—that they can't all be instantiated together—and thus that not all possible worlds are compossible—that they can't all be instantiated together. While it is easy to appreciate Leibniz's reasons for embracing this view, it has proven difficult to see how his doctrine of incompossibility might be reconciled with the broader commitments of his larger philosophical system. This essay develops, in four sections, a novel solution to the "puzzle of incompossibility." The first section frames the difficulty more carefully and briefly argues that the two dominant strategies developed by Leibniz's commentators fail to solve it fully insofar as they require simply abandoning one or another of its motivating commitments. The second and third sections show how Leibniz's guiding analogy of a geometrical packing or tiling problem may be applied to solve the puzzle of incompossibility in the context of finite and infinite worlds composed of extended corporeal substances. Finally, the fourth section shows how the strategy of Leibniz's packing analogy might be applied even in the context of a thoroughly idealist metaphysics in which the only true substances are nonextended, mindlike "monads." The essay concludes by drawing some connections between Leibniz's thinking about the puzzle of incompossibility and the development of his views concerning the status of corporeal substances and extended bodies. CiteULike Connotea Del.icio.us Digg Reddit Technorati What's this?

This paper aims to offer a sympathetic reading of Berkeley’s often maligned account of human agency. The first section briefly revisits three options concerning the relationship between human and divine agency available to theistically minded philosophers in the medieval and early modern eras. The second argues that, of those three views, only the position of concurrentism is consistent with Berkeley’s texts. The third section explores Berkeley’s reasons for adopting concurrentism by highlighting three motivating considerations drawn from his larger philosophical system. Finally, the fourth section attempts to flesh out Berkeley’s understanding of human activity by looking at how we might understand his claim that “we move our legs ourselves” in light of his commitments to idealism and concurrentism.

In this paper I argue that the hoary theological doctrine of divine concurrence poses no deep threat to Leibniz’s views on theodicy and creaturely activity even as those views have been traditionally understood. The first three sections examine respectively Leibniz’s views on creation, conservation and concurrence, with an eye towards showing their sys­tematic compatibility with Leibniz’s theodicy and metaphysics. The fourth section takes up remaining worries arising from the bridging principle that conservation is a continued or continuous creation, and argues that they can be allayed once two readings of the prin­ciple are distinguished. What emerges from the discussion as a whole is, I hope, a clearer picture of Leibniz’s views on the nature of monadic causation, his understanding of the relationship between divine and creaturely activity, and his position with respect to later medieval and early modern debates over secondary causation

Leibniz speaks, in a variety of contexts, of there being two realms—a "kingdom of power or efficient causes" and "a kingdom of wisdom or final causes." This essay explores an often overlooked application of Leibniz's famous "two realms doctrine." The first part turns to Leibniz's work in optics for the roots of his view that nature can be seen as being governed by two complete sets of equipotent laws, with one set corresponding to the efficient causal order of the world, and the other to its teleological order. The second part offers an account of how this picture of lawful over-determination is to be reconciled with Leibniz's mature metaphysics. The third addresses a line of objection proposed by David Hirschmann to the effect that Leibniz's doctrine undermines his stated commitment to an efficient, broadly mechanical account of the natural world. Finally, the fourth part suggests that Leibniz's thinking about the harmony of final and efficient causes in connection with corporeal nature may help to shed light on his understanding of the teleological unfolding of monads as well.

This essay offers an account of the relationship between extended Leibnizian bodies and unextended Leibnizian monads, an account that shows why Leibniz was right to see intimate, explanatory connections between his studies in physics and his mature metaphysics. The first section sets the stage by introducing a case study from Leibniz's technical work on the strength of extended, rigid beams. The second section draws on that case study to introduce a model for understanding Leibniz's views on the relationship between derivative and primitive forces. The third section draws on Leibniz's understanding of the relationship between derivative and primitive forces in order to shed light, in turn, on his understanding of the relationship between extended, material bodies and unextended, immaterial monads. The fourth section responds to a likely objection by arguing that Leibniz's monads may, in a perfectly reasonable sense, be spatially located

Leibniz’s mature philosophical understanding of the laws of nature emerges rather suddenly in the late 1670’s to early 1680’s and is signaled by his embrace of three central theses.1 The first, what I’ll call the thesis of Contingency, suggests that the laws of nature are not only contingent, but, in some sense, paradigmatically contingent; they are supposed to provide insight into the very nature of contingency as Leibniz comes to understand it. The second, what I’ll call the thesis of Providence, suggests that the laws of nature provide a basis for a new argument from design by showing how reflection on God’s ends can be positively useful in the practice of natural philosophy. The third, what I’ll call thesis of ..

In his Kant and the Claims of Knowledge, Paul Guyer offers an influential reading of Kant’s famous “Refutation of Idealism.” Guyer’s reading has been widely praised as Kantian exegesis but less favorably received as an anti-skeptical line of argument worthy of contemporary interest. In this paper, I focus on defending the general thrust of Guyer’s reading as a response to Cartesian skepticism. The paper falls into two sections. The first section constructs Guyer’s central argument in three steps and gives it a quasi-formal presentation. That presentation reveals the principal obstacle to the argument’s being convincing to a contemporary audience, namely, its apparent reliance on Kant’s prohibition against psychological laws governing mental states. The second section constructs a lemma in defense of Guyer’s general line of attack. In effect, it suggests that that line does not depend on a metaphysical ban on psychological laws, but only on the modest premise that according to the Cartesian’s concept of knowledge such laws cannot justify claims about the temporal order of the self.

In this essay, we explore a fresh avenue into mind-body dualism by considering a seemingly distant question posed by Frege: "Why is it absurd to suppose that Julius Caesar is a number?". The essay falls into three main parts. In the first, through an exploration of Frege’s Julius Caesar problem, we attempt to expose two maxims applicable to the mind-body problem. In the second part, we draw on those maxims in arguing that “full blown dualism” is preferable to more modest, property-theoretic, versions. Finally, in the third part we close by suggesting that full blown dualism need not be spooky, resurrecting a broadly Lockean, rather than Cartesian, metaphysical picture.