Lisa Downing

While De Motu, Berkeley's treatise on the philosophical foundations of mechanics, has frequently been cited for the surprisingly modern ring of certain of its passages, it has not often been taken as seriously as Berkeley hoped it would be. Even A.A. Luce, in his editor's introduction to De Motu, describes it as a modest work, of limited scope. Luce writes: The De Motu is written in good, correct Latin, but in construction and balance the workmanship falls below Berkeley's usual standards. The title is ambitious for so brief a tract, and may lead the reader to expect a more sustained argument than he will find. A more modest title, say Motion without Matter, would fitly describe its scope and content. Regarded as a treatise on motion in general, it is a slight and disappointing work; but viewed from a narrower angle, it is of absorbing interest and high importance. It is the application of immaterialism to contemporary problems of motion, and should be read as such....apart from the Principles the De Motu would be nonsense.1..

That corpuscularianism played a critical role in Locke’s philosophical thought has perhaps now attained the status of a truism. In particular, it is universally acknowledged that the primary/secondary quality distinction and the conception of real essence found in the Essay Concerning Human Understanding cannot be understood apart from the corpuscularian science of Locke’s time.1 When Locke provides lists of the primary qualities of bodies,2 the qualities that “are really in them whether we perceive them or no,” those lists show strong resemblances to Robert Boyle’s views about the “primary affections” of matter, as expressed in such influential programmatic works as On the Origin of Forms and Qualities.3 Moreover, Locke’s conception of the real essences of bodies, the inner constitutions which serve as the causal sources of all their properties, typically appears to be a corpuscularian one.4 Nevertheless, the question of the nature of Locke’s philosophical allegiance to corpuscularianism remains a controversial one.5..

One of the deepest tensions in Locke’s Essay, a work full of profound and productive conflicts, is one between Locke’s metaphysical tendencies—his inclination to presuppose or even to argue for substantive metaphysical positions—and his devout epistemic modesty, which seems to urge agnosticism about major metaphysical issues. Both tendencies are deeply rooted in the Essay. Locke is a theorist of substance, essence, quality. Yet, his favorite conclusions are epistemically pessimistic, even skeptical; when it comes to questions about how the world is constituted, our understandings cannot penetrate very far. Locke seems torn between metaphysics and modesty, between dogmatism and skepticism. This chapter will consider two specific examples of this sort of tension. The first involves the ontology of body, and the second, the ontology of mind. The conflict concerning bodily natures looks like this: As is well-known, Locke typically describes bodies in the terms of the corpuscularian science of his day, as exemplified especially by the natural philosopher Robert Boyle. Locke’s characterizations of the real essences of bodies are mechanist. He envisions them as corpuscularian textures-- spatial arrangements of particles possessing size.

With Spirits and Clocks, Dennis Des Chene completes a two-part project begun with Life’s Form: Late Aristotelian Conceptions of the Soul. In both volumes, Des Chene is concerned with the question of what makes living things living. For the Jesuit Aristotelians, the answer requires a complex analysis of the ontology of soul and power. For Descartes, of course, the answer is completely different; arguably, there is a sense in which his answer is: nothing. Indeed Des Chene does argue this, concluding that for Descartes there are no living things in the Aristotelian sense: the body machine does not live, because it has no powers; the soul does not live because it has no role in nutrition, growth, and generation. Descartes’s physiology thus represents the most radical aspect of his natural philosophy, for he must eliminate souls from living things as part of the general project of eliminating Aristotelian forms from nature. As such, the importance of Descartes’s physiology is manifest; Des Chene’s study is a very welcome and original addition to the still-modest philosophical literature engaged with Descartes’sL’Homme and La description du corps humain.

Although George Berkeley himself made no major scientific discoveries, nor formulated any novel theories, he was nonetheless actively concerned with the rapidly evolving science of the early eighteenth century. Berkeley's works display his keen interest in natural philosophy and mathematics from his earliest writings (Arithmetica, 1707) to his latest (Siris, 1744). Moreover, much of his philosophy is fundamentally shaped by his engagement with the science of his time. In Berkeley's best-known philosophical works, the Principles and Dialogues, he sets up his idealistic system in opposition to the materialist mechanism he finds in Descartes and Locke. In De Motu, Berkeley refines and extends his philosophy of science in the context of a critique of the dynamic accounts of motion offered by Newton and Leibniz. And in Siris, Berkeley's flirtation with neo-Platonism draws inspiration from the fire theory of Boerhaave as well as Newton's aetherial speculations in the Queries of the Optics. In examining Berkeley's critical engagement with the natural philosophy of his time, we will thus improve our understanding of not just his philosophy of science, but of his philosophical corpus as a whole.

The rich connections between metaphysics and natural philosophy in the early modern period have been widely acknowledged and productively mined, thanks in no small part to the work of Margaret Wilson, whose book, Descartes, served as an inspirational example for a generation of scholars. The task of this paper is to investigate one particular such connection, namely, the relation between occasionalist metaphysics and strict mechanism. My focus will be on the work of Nicholas Malebranche, the most influential Cartesian philosopher after Descartes himself. I begin with two crucial facts about Malebranche’s philosophy: (1) Malebranche was an occasionalist, that is, he held that God was the only true cause, that all modifications of bodies and of minds can be produced by God alone. (2) Malebranche adhered firmly to strict mechanism. By strict mechanism, I mean the view, found most prominently in Descartes and in Boyle’s more ideological writings, that the qualities of bodies are exhausted by a very short list (size, shape, motion, and perhaps solidity) and that, most importantly, bodies interact only at contact by impact. Another way of describing this “contact action” requirement is as the thesis that the only fundamental laws of physics are laws of inertial motion and laws of the communication of motion at impact. In..