John McGuire

We argue that Isaac Newton really is best understood as being in the tradition of the Mechanical Philosophy and, further, that Newton saw himself as being in this tradition. But the tradition as Newton understands it is not that of Robert Boyle and many others, for whom the Mechanical Philosophy was defined by contact action and a corpuscularean theory of matter. Instead, as we argue in this paper, Newton interpreted and extended the Mechanical Philosophy's slogan “matter and motion” in reference to the long and distinguished tradition of mixed mathematics and the study of simple machines

This paper offers a detailed account of arguments in De Caelo I by which Aristotle tried to demonstrate the necessity of the perpetual existence and the perpetual rotation of the cosmos. On our interpretation, Aristotle’s arguments are naturalistic. Instead of being based (as many have thought) on rules of logic and language, they depend, we argue, on natural science theories about abilities (δυνάμεις), e.g., to move and to change, which things have by nature and about the conditions under which these abilities can be exercised. Our interpretation locates the De Caelo arguments in the context of some central doctrines of the Organon, the Metaphysics, the Physics, and other texts. The De Caelo arguments fit a number of views developed in these texts. Aristotle’s treatments of local motion, of natural motion and change, of necessity and possibility, and of abilities and their exercises are examples. But, as we interpret them, the De Caelo arguments raise serious questions about the role of (and the need for) Metaphysics A’s soulful Unmoved Mover in Aristotle’s overall natural-scientific picture.

This essay explores the role of God’s omnipresence in Newton’s natural philosophy, with special emphasis placed on how God is related to space. Unlike Descartes’ conception, which denies the spatiality of God, or Gassendi and Charleton’s view, which regards God as completely whole in every part of space, it is argued that Newton accepts spatial extension as a basic aspect of God’s omnipresence. The historical background to Newton’s spatial ontology assumes a large part of our investigation, but with attention also focused on the details of Newton’s unique approach to these traditional Scholastic conceptions.

Isaac Newton wrote the manuscript Questiones quaedam philosophicae at the very beginning of his scientific career. This small notebook thus affords rare insight into the beginnings of Newton's thought and the foundations of his subsequent intellectual development. The Questiones contains a series of entries in Newton's hand that range over many topics in science, philosophy, psychology, theology, and the foundations of mathematics. These notes, written in English, provide a very detailed picture of Newton's early interests, and record his critical appraisal of contemporary issues in natural philosophy. Written predominantly in 1664-5, they give a significant perspective on Newton's thought just prior to his annus mirabilis, 1666. This volume provides a complete transcription of the Questiones, together with an 'expansion' into modern English, and a full editorial commentary on the content and significance of the notebook in the development of Newton's thought. It will be essential reading for all those interested in Newton and the intellectual foundations of science.

Descartes's works are often treated as a unified, unchanging whole. But in Descartes's Changing Mind, Peter Machamer and J. E. McGuire argue that the philosopher's views, particularly in natural philosophy, actually change radically between his early and later works--and that any interpretation of Descartes must take account of these changes. The first comprehensive study of the most significant of these shifts, this book also provides a new picture of the development of Cartesian science, epistemology, and metaphysics. No changes in Descartes's thought are more significant than those that occur between the major works The World and Principles of Philosophy. Often seen as two versions of the same natural philosophy, these works are in fact profoundly different, containing distinct conceptions of causality and epistemology. Machamer and McGuire trace the implications of these changes and others that follow from them, including Descartes's rejection of the method of abstraction as a means of acquiring knowledge, his insistence on the infinitude of God's power, and his claim that human knowledge is limited to that which enables us to grasp the workings of the world and develop scientific theories.