ABSTRACTThis paper expounds and critically assesses G. W. Leibniz’s mature theory of the cohesion of material bodies. Leibniz’s later view of cohesion was forged in polemical engagement with the views of John Locke and the Dutch natural philosopher Nicolaas Hartsoeker and it is in Leibniz’s response to Locke in his New Essays on Human Understanding, and especially his correspondence with Hartsoeker, that the theory is revealed. After setting out Locke’s theory of solidity and cohesion, the paper examines Leibniz’s response to (...) Locke in the New Essays. It then proceeds to the mechanical theory of conspiring motions developed in the Hartsoeker correspondence. The final section of the paper poses three problems for Leibniz’s theory – explanatory, empirical, and conceptual. (shrink)

One of the most pressing philosophical problems in early modern Europe concerned how the soul and body could form a unity, or, as many understood it, how these two substances could work together. It was widely believed that there were three (and only three) hypotheses regarding the union of soul and body: (1) physical influence, (2) occasionalism, and (3) pre-established harmony. However, in 1763, a fourth hypothesis was put forward by the French thinker André-Pierre Le Guay de Prémontval (1716–1764). Prémontval’s (...) hypothesis, given the grand name of “psychocracy” (i.e., the dominion or the rule of the soul), held that there was a real influence between soul and body, but that this was an immaterial kind of influence as opposed to the physical kind that had been entertained heretofore. Prémontval’s hypothesis is the focus of this paper. I shall begin by sketching out the details of Prémontval’s hypothesis (Section 1), then proceed to consider its claims to constitute a true fourth hypothesis distinct from the other three (Section 2), before closing by briefly considering two objections and the responses either that Prémontval himself made or that may be made on his behalf (Section 3). (shrink)

This essay presents an alternative to contemporary substantivalist and relationist interpretations of quantum gravity hypotheses by means of an historical comparison with the ontology of space in the seventeenth century. Utilizing differences in the spatial geometry between the foundational theory and the theory derived from the foundational, in conjunction with nominalism and platonism, it will be argued that there are crucial similarities between seventeenth century and contemporary theories of space, and that these similarities reveal a host of underlying conceptual issues (...) that the substantival/relational dichotomy fails to distinguish. (shrink)

This essay examines the relationship between monads and space in Kant’s early pre-critical work, with special attention devoted to the question of ubeity, a Scholastic doctrine that Leibniz describes as “ways of being somewhere”. By focusing attention on this concept, evidence will be put forward that supports the claim, held by various scholars, that the monad-space relationship in Kant is closer to Leibniz’ original conception than the hypotheses typically offered by the later Leibniz-Wolff school. In addition, Kant’s monadology, in conjunction (...) with God’s role, also helps to shed light on further aspects of his system that are broadly Leibnizian, such as monadic activity and the unity of space. (shrink)

This essay proposes a new interpretation of a central, and yet overlooked, argument Leibniz offers against Descartes’s power-free ontology of the corporeal world. Appealing to considerations about the successiveness of motion, Leibniz attempts to show that the reality of motion requires force. It is often assumed that the argument is driven by concerns inspired by Zeno. Against such a reading, this essay contends that Leibniz’s argument is instead best understood against the background of an Aristotelian view of the priority of (...) real being over time. The essay also shows how this alternative interpretation can help to shed new light on the difference between Leibnizian forces and Aristotelian powers, as well as on Leibniz’s famous claim that accounting for force leads us beyond the mechanistic corporeal realm. (shrink)

The article is a critical notice of Daniel Garber, Leibniz: Body, Substance, Monad. Garber presents a developmental reading of Leibniz's metaphysics that focuses on Leibniz's evolving analysis of body and force as the key to his account of substance. Garber claims that Leibniz shifts from an early theory of body to a theory of corporeal substance in his middle years, and only develops a theory of monads in his later writings—and that even then Leibniz looks not to abandon the scheme (...) of corporeal substances but to reconcile it with that of monads. The present article considers several challenges to Garber's interpretation, questioning, among other things, Garber's claims about development and Garber's account of Leibniz's primary arguments for the theory of monads. The article concludes that while crucial elements of the standard interpretation of Leibniz as an idealist can be defended against Garber's critique, the original traditional view that takes the theory of monads as the first and most fundamental principle of Leibniz's metaphysics is no longer sustainable. (shrink)

Leibniz’s ‘new science of dynamics’ is typically taken to have been completed in the late monadological metaphysics. On this view, stemming from Martial Gueroult and continuing in the recent interpretations of Robert Adams and Pauline Phemister, Leibniz accomplished his dynamics in his later account of physical forces as merely phenomenal modifications of monadic, metaphysical forces. This paper argues, by contrast, that Leibniz considered the dynamics to be an unfinished project: this is evident in statements from throughout his mature period until (...) his final months. Two possible reasons for the non-completion of the dynamics are discussed. The first is that his encounter with the superior physics of Newton’s Principia caused Leibniz to continually defer his own contribution. I argue, however, in favour of a second reason: that there are philosophical difficulties inherent in the science of dynamics that prevented its completion. These difficulties are found in the relation of dynamics to metaphysics, and in the more fundamental split within dynamics, into the doctrine of primitive and derivative forces. Through three late exchanges with de Volder, Wolff and Des Bosses, I show that the relation of primitive and derivative forces remained an unsolved – although not in principle unsolvable – problem for Leibniz. (shrink)

This paper is concerned with the status of mathematical fictions in Leibniz’s work and especially with infinitary quantities as fictions. Thus, it is maintained that mathematical fictions constitute a kind of symbolic notion that implies various degrees of impossibility. With this framework, different kinds of notions of possibility and impossibility are proposed, reviewing the usual interpretation of both modal concepts, which appeals to the consistency property. Thus, three concepts of the possibility/impossibility pair are distinguished; they give rise, in turn, to (...) three concepts of mathematical fictions. Moreover, such a distinction is the base for the claim that infinitesimal quantities, as mathematical fictions, do not imply an absolute impossibility, resulting from self-contradiction, but a relative impossibility, founded on irrepresentability and on the fact that it does not conform to architectural principles. In conclusion, this “soft” impossibility of infinitesimals yields them, in Leibniz view, a presumptive or “conjectural” status. (shrink)

This anthology is about the signal change in Leibniz’s metaphysics with his explicit adoption of substantial forms in 1678-79. This change can either be seen as a moment of discontinuity with his metaphysics of maturity or as a moment of continuity, such as a passage to the metaphysics from his last years. Between the end of his sejour at Paris and the first part of the Hanover period, Leibniz reformed his dynamics and began to use the theory of corporeal substance. (...) This book explores a very important part of the philosophical work of the young Leibniz. Expertise from around the globe is collated here, including Daniel Garber’s work based on the recent publication of Leibniz's correspondence from the late 1690s, examining how the theory of monads developed during these crucial years. Richard Arthur argues that the introduction of substantial forms, reinterpreted as enduring primitive forces of action in each corporeal substance, allows Leibniz to found the reality of the phenomena of motion in force and thus avoid reducing motion to a mere appearance. Amongst other themes covered in this book, Pauline Phemister’s paper investigates Leibniz’s views on animals and plants, highlighting changes, modifications and elaborations over time of Leibniz’s views and supporting arguments and paying particular attention to his claim that the future is already contained in the seeds of living things. The editor, Adrian Nita, contributes a paper on the continuity or discontinuity of Leibniz’s work on the question of the unity and identity of substance from the perspective of the relation with soul and mind. (shrink)

This essay demonstrates the inadequacy of contemporary substantivalist and relationist interpretations of quantum gravity hypotheses via an historical investigation of the debate on the underlying ontology of space in the seventeenth century. Viewed in the proper context, there are crucial similarities between seventeenth century theories of space and contemporary work on the ontological foundations of spacetime theories, and these similarities challenge the utility of the substantival/relational dichotomy by revealing a host of underlying conceptual issues that do not naturally align with (...) that distinction. (shrink)