This paper considers Newton’s position on gravity’s cause, both conceptually and historically. With respect to the historical question, I argue that while Newton entertained various hypotheses about gravity’s cause, he never endorsed any of them, and in particular, his lack of confidence in the hypothesis of robust and unmediated distant action by matter is explained by an inclination toward certain metaphysical principles. The conceptual problem about gravity’s cause, which I identified earlier along with a deeper problem about individuating substances, is (...) that a decisive conclusion is impossible unless certain speculative aspects of his empiricism are abandoned. In this paper, I situate those conceptual problems in Newton’s natural philosophy. They arise from ideas that push empiricism to potentially self-defeating limits, revealing the danger of allowing immaterial spirits any place in natural philosophy, especially spatially extended spirits supposed capable of co-occupying place with material bodies. Yet because their source ideas are speculative, Newton’s method ensures that these problems pose no threat to his rational mechanics or the profitable core of his empiricism. They are easily avoided by avoiding their source ideas, and when science emerges from natural philosophy, it does so with an ontology unencumbered by immaterial spirits. (shrink)

This study explores several arguments against Spinoza's philosophy that were developed by Henry More, Samuel Clarke, and Colin Maclaurin. In the arguments on which I focus, More, Clarke, and Maclaurin aim to establish the existence of an immaterial and intelligent God precisely by showing that Spinoza does not have the resources to adequately explain the origin of motion. Attending to these criticisms grants us a deeper appreciation for how the authority derived from the empirical success of Newton's enterprise was used (...) to settle debates within philosophy. What I emphasize is that in the progression from More to Clarke to Maclaurin, key Newtonian concepts from the Principia (1687), such as motion, atomism, and the vacuum, are introduced and exploited in order to challenge the account of matter and motion that is presented in Spinoza's Ethics (1677). Building on this treatment, I use the arguments from More and Clarke especially to help discern the anti-Spinozism that can be detected in Newton's General Scholium (1713). Ultimately, the Newtonian criticisms that I detail offer us a more nuanced view of the problems that plague Spinoza's philosophy, and they also challenge the idea that Spinoza seamlessly fits into a progressive narrative about the scientific revolution. (shrink)

This paper is a critical response to Hylarie Kochiras’ “Gravity and Newton’s substance counting problem,” Studies in History and Philosophy of Science 40 267–280. First, the paper argues that Kochiras conflates substances and beings; it proceeds to show that Newton is a substance monist. The paper argues that on methodological grounds Newton has adequate resources to respond to the metaphysical problems diagnosed by Kochiras. Second, the paper argues against the claim that Newton is committed to two speculative doctrines attributed to (...) him by Kochiras and earlier Andrew Janiak: i) the passivity of matter and ii) the principle of local causation. Third, the paper argues that while Kochiras’ arguments about Newton’s metaphysical commitments are mistaken, it qualifies the characterization of Newton as an extreme empiricist as defended by Howard Stein and Rob DiSalle. In particular, the paper shows that Newton’s empiricism was an intellectual and developmental achievement that built on non trivial speculative commitments about the nature of matter and space.Keywords: Newton; Substance; Action at a distance; Space; Matter; Empiricism. (shrink)

I examine Du Châtelet’s methodology for physics and metaphysics through the lens of her engagement with Newton’s Rules for Reasoning in Natural Philosophy. I first show that her early manuscript writings discuss and endorse these Rules. Then, I argue that her famous published account of hypotheses continues to invoke close analogues of Rules 3 and 4, despite various developments in her position. Once relevant experimental evidence and some basic constraints are met, it is legitimate to inductively generalize from observations; general (...) hypotheses can thereafter be assumed as true until contrary experiments show otherwise. I conclude by arguing that this account of induction plays an essential role in her metaphysics, both in an argument for simple substances—which has an inductive premise—and in her attempt to distinguish acceptable and unacceptable metaphysical commitments. (shrink)

Newton published his deduction of universal gravity in Principia (first ed., 1687). To establish the universality (the particle-to-particle nature) of gravity, Newton must establish the additivity of mass. I call ‘additivity’ the property a body's quantity of matter has just in case, if gravitational force is proportional to that quantity, the force can be taken to be the sum of forces proportional to each particle's quantity of matter. Newton's argument for additivity is obscure. I analyze and assess manuscript versions of (...) Newton's initial argument within his initial deduction, dating from early 1685. Newton's strategy depends on distinguishing two quantities of matter, which I call ‘active’ and ‘passive’, by how they are measured. These measurement procedures frame conditions on the additivity of each quantity so measured. While Newton has direct evidence for the additivity of passive quantity of matter, he does not for that of the active quantity. Instead, he tries to infer the latter from the former via conceptual analyses of the third law of motion grounded largely on analogies to magnetic attractions. The conditions needed to establish passive additivity frustrate Newton's attempted inference to active additivity. (shrink)

Much has been written on Newton’s concept of matter, as well as Newton’s laws. Meanwhile, the metaphysical and epistemological relationships between these two principal features of Newtonian philosophy are relatively unexplored. Among the existing accounts of the relationship between bodies and laws, two are especially compelling: the “law-constitutive” approach from Katherine Brading and the “formal-cause” approach from Zvi Biener and Eric Schliesser. Both accounts argue that Newton’s bodies are (at least partially) metaphysically dependent on the laws. That is, according to (...) Brading, Biener, and Schliesser, Newtonian laws are ontologically prior to the bodies they govern. In this article, I reply to Brading, Biener, and Schliesser. I develop negative arguments against their approaches by closely examining three features of Newton’s ontology—forms, particles, and active principles—and their relationship to the laws. I also offer an explanation as to why “law-first” approaches have (understandably) dominated recent Newtonian exegesis. Finally, I present a positive argument for what I believe to be a superior alternative: Newton’s law-first approach is purely pragmatic. It is a feature of his experimental philosophy that we should begin our inquiry into the metaphysical constituents of the universe with the laws that arise from them. This does not entail, however, that Newton views laws as constituting or forming physical bodies. Newton’s metaphysics should be interpreted as “matter-first,” with bodies giving rise to laws, whereas his epistemology should be interpreted as “law-first,” with knowledge of laws giving rise to knowledge of bodies. (shrink)

I discuss the three distinctions “absolute and relative”, “true and apparent”, and “mathematical and common”, for the specific case of time in Newton’s Principia. I argue that all three distinctions are needed for the project of the Principia and can be understood within the context of that project without appeal to Newton’s wider metaphysical and theological commitments. I argue that, within the context of the Principia, the three claims that time is absolute rather than relative, true rather than apparent, and (...) mathematical rather than common, are to be evaluated with respect to the needs of, and relative to the success of, the project of the Principia. I claim that Newton is thereby offering a new, and empirical, philosophy of time. (shrink)

The Oxford Handbook of the History of Physics brings together cutting-edge writing by more than twenty leading authorities on the history of physics from the seventeenth century to the present day. By presenting a wide diversity of studies in a single volume, it provides authoritative introductions to scholarly contributions that have tended to be dispersed in journals and books not easily accessible to the general reader. While the core thread remains the theories and experimental practices of physics, the Handbook contains (...) chapters on other dimensions that have their place in any rounded history. These include the role of lecturing and textbooks in the communication of knowledge, the contribution of instrument-makers and instrument-making companies in providing for the needs of both research and lecture demonstrations, and the growing importance of the many interfaces between academic physics, industry, and the military. (shrink)

This chapter explains how the rise of the Mechanical philosophy during the seventeenth century contributed to the transformation of the traditional, Aristotelian schema of four causes into the dominance of efficient causation as the paradigmatic cause by the time of David Hume. But the chapter simultaneously shows that the mechanical philosophy also gave rise to a number of problems internal to it, as diagnosed by Newton and Newtonian natural philosophers, that facilitated more careful analysis of the nature of causation.