This paper draws attention to the crucial importance of a new kind of precisely defined law of nature in the Scientific Revolution. All explanations in the mechanical philosophy depend upon the interactions of moving material particles; the laws of nature stipulate precisely how these interact; therefore, such explanations rely on the laws of nature. While this is obvious, the radically innovatory nature of these laws is not fully acknowledged in the historical literature. Indeed, a number of scholars have tried to (...) locate the origins of such laws in the medieval period. In the first part of this paper these claims are critically examined, and found at best to reveal important aspects of the background to the later idea, which could be drawn upon for legitimating purposes by the mechanical philosophers. The second part of the paper argues that the modern concept of laws of nature originates in René Descartes's work. It is shown that Descartes took his concept of laws of nature from the mathematical tradition, but recognized that he could not export it to the domain of physico-mathematics, to play a causal role, unless he could show that these laws were underwritten by God. It is argued that this is why, at an early stage of his philosophical development, Descartes had to turn to metaphysics. (shrink)

(2013). The Theological Foundation of Hobbesian Physics: A Defence of Corporeal God. British Journal for the History of Philosophy: Vol. 21, No. 2, pp. 240-261. doi: 10.1080/09608788.2012.692663.

The idea of active power played central role in the 17th Century philosophy and science. The idea is as follows: if not prevented, bodies necessarily do certain things in virtue of their power. This kind of thought naturally arose from what might properly be called the law of persistence, according to which moving bodies continue their motion unchanged if no new external force intervenes.1 What bodies do in virtue of their power was called actions, and in terms of actions such (...) things as resistance, pressure and affections were explained. What is this active power? One of the main aims of philosophers in the 17th and 18th Centuries was to find a good answer to this question. (shrink)

Descartes was disappointed with most of the Objections collected to accompany the Meditations in 1641, but he took a particularly dim view of the Third Set. ‘I am surprised that I have found not one valid argument in these objections,’ he wrote, close to the end of a series of curt and dismissive replies. The author of the objections was Thomas Hobbes. There was one other unfriendly exchange between Descartes and Hobbes in 1641. Descartes received through Mersenne some letters criticizing (...) theses in the Dioptrics, one of the Essays published with the Discourse on Method in 1637. Mersenne did not name Hobbes as the writer of the letters, attributing them to an unspecified Englishman, and it seems that Descartes never connected the critic of his optics with the author of the objections to his metaphysics. Nevertheless, Descartes responded with some hostility to the letters, angrily rebutting some points about refraction and charging that others had been appropriated from his own writings. Insinuating that the English correspondent was dishonest, Descartes decided to have no more to do with him. A meeting between the two men did take place in 1648 at a dinner given by the Marquis of Newcastle, but even on this occasion they did not see eye to eye, getting into an argument about the nature of hardness. (shrink)

: This paper investigates the influence of Galileo's natural philosophy on the philosophical and methodological doctrines of Thomas Hobbes. In particular, I argue that what Hobbes took away from his encounter with Galileo was the fundamental idea that the world is a mechanical system in which everything can be understood in terms of mathematically-specifiable laws of motion. After tracing the history of Hobbes's encounters with Galilean science (through the "Welbeck group" connected with William Cavendish, earl of Newcastle and the "Mersenne (...) circle" in Paris), I argue that Hobbes's 1655 treatise De Corpore is deeply indebted to Galileo. More specifically, I show that Hobbes's mechanistic theory of mind owes a significant debt to Galileo while his treatment of the geometry of parabolic figures in chapter 16 of De Corpore was taken almost straight out of the account of accelerated motion Two New Sciences. (shrink)

: In this paper I address the vexed question of secondary causation in René Descartes' physics, and examine several influential interpretations, especially the one recently proposed by Dennis Des Chene. I argue that interpreters who regard Cartesian bodies as real secondary causes, on the grounds that the modes of body include real forces, contradict Descartes' account of modes. On the other hand, those who deny that Descartes affirms secondary causation, on the grounds that forces cannot be modes of extension, commit (...) Descartes to the problematic view that the undetermined and immutable will of God is the sole cause of determinate and variable motions. Des Chene's contextualist approach to Descartes' texts leads him to an intermediate position that combines elements of both interpretations. However, in my view, Des Chene's interpretation likewise fails to resolve apparent tensions in Descartes' claims. I thus propose to separate the issue of secondary causation from what Des Chene dubs 'the problem of force'. On the basis of this approach, and a study of Jesuit commentaries familiar to Descartes, I develop a new interpretation which takes seriously Descartes' claim that the laws of nature are the secondary and particular causes of particular motions and changes in motion. (shrink)

The selections contained in these volumes from the papers and letters of Leibniz are intended to serve the student in two ways: first, by providing a more adequate and balanced conception of the full range and penetration of Leibniz's creative intellectual powers; second, by inviting a fresher approach to his intellectual growth and a clearer perception of the internal strains in his thinking, through a chronological arrangement. Much confusion has arisen in the past through a neglect of the develop ment (...) of Leibniz's ideas, and Couturat's impressive plea, in his edition of the Opuscu/es et fragments (p. xii), for such an arrangement is valid even for incomplete editions. The beginning student will do well, however, to read the maturer writings of Parts II, III, and IV first, leaving Part I, from a period too largely neglected by Leibniz criticism, for a later study of the still obscure sources and motives of his thought. The Introduction aims primarily to provide cultural orientation and an exposition of the structure and the underlying assumptions of the philosophical system rather than a critical evaluation. I hope that together with the notes and the Index, it will provide those aids to the understanding which the originality of Leibniz's scientific, ethical, and metaphysical efforts deserve. (shrink)

Are Hobbes's laws of nature to be understood primarily as theorems of reason, or as commands of God, or as commands of the civil sovereign? Each of these accounts can be given textual support; each identifies a role that the laws may be thought to play. Examining the full range of textual references, discussing the place of the laws of nature in Hobbes's argument, and considering how the laws may be known, give strongest support to the first of the three (...) accounts, that the laws are primarily rational precepts and only secondarily civil and divine commands. (shrink)

This dictionary provides a comprehensive and cohesive expository account of about one hundred and fifty key concepts covering the entire range of Hobbes's thought, from philosophy, political theory and science, to theology, history and mathematics.

_ Source: _Volume 29, Issue 1, pp 9 - 38 Hobbes tried to develop a strict version of the mechanical philosophy, in which all physical phenomena were explained only in terms of bodies in motion, and the only forces allowed were forces of collision or impact. This ambition puts Hobbes into a select group of original thinkers, alongside Galileo, Isaac Beeckman, and Descartes. No other early modern thinkers developed a strict version of the mechanical philosophy. Natural philosophies relying solely on (...) bodies in motion require a concept of inertial motion. Beeckman and Descartes assumed rectilinear motions were rectilinear, but Galileo adopted a theory which has been referred to as circular inertia. Hobbes’s natural philosophy depended to a large extent on what he called “simple circular motions.” In this paper, I argue that Hobbes’s simple circular motions derived from Galileo’s belief in circular inertia. The paper opens with a section outlining Galileo’s concept, the following section shows how Hobbes’s physics depended upon circular motions, which are held to continue indefinitely. A third section shows the difficulty Hobbes had in maintaining a strictly mechanistic philosophy, and the conclusion offers some speculations as to why Galileo’s circular inertia was never entertained as a serious rival to rectilinear inertia, except by Hobbes. (shrink)

_ Source: _Volume 29, Issue 1, pp 66 - 85 This paper will deal with the notion of _conatus_ and the role it plays in Hobbes’s program for natural philosophy. As defined by Hobbes, the _conatus_ of a body is essentially its instantaneous motion, and he sees this as the means to account for a variety of phenomena in both natural philosophy and mathematics. Although I foucs principally on Hobbesian physics, I will also consider the extent to which Hobbes’s account (...) of _conatus_ does important explanatory work in his theory of human perception, psychology, and political philosophy. I argue that, in the end, there are important limitations in Hobbes’s account of _conatus_, but that Leibniz adapted the concept in important ways in developing his science of dynamics. (shrink)

It is difficult to evaluate the role of activity - of force or of that which has causal efficacy - in Descartes’ natural philosophy. On the one hand, Descartes claims to include in his natural philosophy only that which can be described geometrically, which amounts to matter (extended substance) in motion (where this motion is described kinematically).’ Yet on the other hand, rigorous adherence to a purely geometrical description of matter in motion would make it difficult to account for the (...) interactions among the particles that constitute Descartes’ universe, since the notions of extension and kinematical motion do not in themselves imply any causal agency. There is, after all, no reason to expect that a particle whose single essence is extension, even if we suppose it to be moving, should impart motion to another particle, while conversely, there is no reason to expect a resting particle to hinder the motion of an impinging one. Descartes' hankering for an austere ontology of matter in motion is in danger of excluding causal agency (force, conceived dynmically) from matter. To the modern reader it may seem obvious that Descartes did not get himself into such a fix, since matter in motion so readily reminds us of kinetic energy or of some more primitive notion of force. Yet by no means is it obvious that Descartes attributed causal efficacy to matter in motion per se. Serious scholars have held opposite positions on this issue. Westfall, Gabbey, and others’ have argued that although on the metaphysical plane Descartes attempted to eliminate force from his mechanical universe, nonetheless ‘force is a real feature’ of his mechanical world. The thrust of this view is that Descartes conceived of force as ‘the capacity of a body in motion to act’, by means of impact, upon other bodies. An opposing interpretation, defended here, is that Descartes did in fact deny causal agency to moving matter per se, restricting agency to immaterial substances such as the human mind, angels, and God. The intention of this interpretation is not to de-emphasize the role of matter in motion in Descartes’ explanation of nature, but rather to stress the fact that Descartes did not conceive of this moving matter dynamically. -/- Reprinted in Descartes, ed. by J. Cottingham, Oxford Readings in Philosophy (Oxford: Oxford University Press, 1998), 281–310. (shrink)

Arguing for controversial readings of many of the canonical figures, the book also focuses on lesser-known writers such as Pierre-Sylvain Regis, Nicolas ...

Michael Hunter has done more than any single person since Thomas Birch to make the study of Robert Boyle convenient and enjoyable, and here, ably assisted by Edward B. Davis, he has put us all further in his debt with a compact and readable edition of the philosophically important Free Enquiry into the Notion of Nature.