Eric Schliesser

This chapter explains what Isaac Newton means with the phrase “absolute, true, and mathematical time” in order to discuss some of the philosophic issues that it gives rise to. It describes Newton's thought in light of a number of scientific, technological, and metaphysical issues that arose in seventeenth‐century natural philosophy. The first section discusses some of the relevant context from the history of Galilean, mathematical natural philosophy, especially as exhibited by the work of Christiaan Huygens. The second section offers a close reading of what Newton says about time in the Principia's Scholium to the definitions. It argues that Newton allows us to conceptually distinguish between “true” and “absolute” time from the vantage point of Newton's dynamics. The third section, in the context of a brief account of Descartes' views on time, discusses the material that Newton added to the second edition of the Principia in the General Scholium.

This chapter argues that the standard conception of Spinoza as a fellow-travelling mechanical philosopher and proto-scientific naturalist is misleading. It argues, first, that Spinoza’s account of the proper method for the study of nature presented in the Theological-Political Treatise (TTP) points away from the one commonly associated with the mechanical philosophy. Moreover, throughout his works Spinoza’s views on the very possibility of knowledge of nature are decidedly sceptical (as specified below). Third, in the seventeenth-century debates over proper methods in the sciences, Spinoza sided with those that criticized the aspirations of those (the physico-mathematicians, Galileo, Huygens, Wallis, Wren, etc) who thought the application of mathematics to nature was the way to make progress. In particular, he offers grounds for doubting their confidence in the significance of measurement as well as their piece-meal methodology (see section 2). Along the way, this chapter offers a new interpretation of common notions in the context of treating Spinoza’s account of motion (see section 3)

The main task for philosophers is introducing, clarifying, articulating, or simply redirecting concepts as—to echo Quine’s poetic formulation— “devices for working a manageable structure into the flux of experience.” I sometimes use “coining concepts” as shorthand for this task. When the concepts are quantitative they are part of a possible science ; when the concepts are qualitative they can be part of a possible philosophy. Of course, in practice, concepts are oft en stillborn, while others have multiple functions in fi elds of inquiry that may straddle philosophy and science. In this chapter I argue that historians of philosophy must, among other things, coin concepts that disclose the near or distant past and create a shared horizon for our philosophical future. In virtue of our expertise we can often do so by drawing on previously orphaned concepts. The more narrow aim of this paper is to introduce two concepts, “Newton’s challenge to philosophy” and, especially, “philosophic prophecy,” that are suitable to philosophers who engage with texts in a scholarly fashion. I do so by re-telling the story of early analytical philosophy and its connection to the reception of Spinoza. By “Newton’s challenge to philosophy,” I mean the following: from about 1700 onward, “natural science” is increasingly taken to be authoritative in settling debates within philosophy; it is a concept that focuses attention on the authority of science and its various manifestations within philosophy. By “philosophic prophecy,” I mean the structured ways in which concept formation by philosophers can shape possible futures, including that of philosophy. In what follows, I first develop and characterize philosophic prophecy more precisely. In order to illuminate the concept, I contrast it with several related, more familiar concepts. Second, I offer brief critical comments on two alternative approaches to the history of philosophy promoted by Quentin Skinner and Michael Kremer in order to make more precise the approach favored here. Third, I offer a fresh narrative about the prehistory and origin of analytical philosophy. My story focuses on Ernest Nagel, who, I claim, is the philosophic prophet of analytical philosophy. Along the way, I explore the shared origins of analytical philosophy and analytical history of philosophy in the anti-Spinozistic writings of George Boole and Bertrand Russell. I oppose Nagel’s and Russell’s narratives in light of Moritz Schlick, the founder of the Vienna Circle. I adopt Schlick’s bold and unappreciated vision of the task of philosophy in scientific age. I focus on his identification of philosophical legislation with qualitative concepts.

In this paper I interpret Newton’s speculative treatment of gravity as a relational, accidental property of matter that arises through what Newton calls “the shared action” of two bodies of matter. In doing so, I expand and extend on a hint by Howard Stein. However, in developing the details of my interpretation I end up disagreeing with Stein’s claim that for Newton a single body can generate a gravity/force field. I argue that when Newton drafted the first edition of the Principia in the mid 1680s, he thought that (at least a part of) the cause of gravity is the disposition inherent in any individual body, but that the force of gravity is the actualization of that disposition; a necessary condition for the actualization of the disposition is the actual obtaining of a relation between two bodies having the disposition. The cause of gravity is not essential to matter because God could have created matter without that disposition. Nevertheless, at least a part of the cause of gravity inheres in individual bodies and were there one body in the universe it would inhere in that body. On the other hand, the force of gravity is neither essential to matter nor inherent in matter, because (to repeat) it is the actualization of a shared disposition. A lone part-less particle would, thus, not generate a gravity field. Seeing this allows us to helpfully distinguish among a) accepting gravity as causally real; b) the cause(s) (e.g. the qualities of matter) of the properties of gravity; c) making claims about the mechanism or medium by which gravity is transmitted. This will help clarify what Newton could have meant when he insisted that gravity is a real force. I present my argument in opposition to Andrew Janiak’s influential and fine 2007 paper. Along the way, I call attention to my disagreement with Janiak on a number of secondary issues (e.g. Janiak’s attribution to Newton of a distinction between ‘local’ and ‘distant’ action; Janiak’s reading of the “Letter to Bentley,” etc).

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