My talk today will be about Newton’s avowed methodology, and specifically the place of experiment in his conception of science, and how his ideas changed significantly over the course of his career. I also want to look at his actual scientific practice and see how this influenced his views on the nature of the experimental sciences.

ArgumentThis paper argues that Samuel Clarke's account of agent causation (i) provides a philosophical basis for moderate voluntarism, and (ii) both leads to and benefits from the acceptance of partial occasionalism as a model of causation for material beings. Clarke's account of agent causation entails that for an agent to be properly called an agent (i.e. causally efficacious), it is essential that the agent is free to choose whether to act or not. This freedom is compatible with the existence of (...) conceptually necessary connections. Hence, Clarke can harmonize God's freedom of choosing with the existence of eternal and necessary relations among things. Moreover, in Clarke's account, only intelligent entities can be properly understood as efficacious causes. Beings deprived of intelligence are not agents or efficacious causes at all and their effects are thus the result of the immediate action of some intelligent being operating upon them. (shrink)

The widely accepted supposition that Newton’s De gravitatione was written in 1684/5 just before composing the Principia is examined. The basis for this determination has serious difficulties starting with the failure to examine the numerical estimates for the resistance of aether. The estimated range is not nearly nil as claimed but comparable with air at or near the earth’s surface. Moreover, the evidence provided most likely stems from experiments by Boyle, Hooke, and others in the 1660s and does not use (...) evidence available in the late 1684. The document supports Newton’s contention that the aether medium incorporates very large voids thereby proving that body and space differ but does by no means completely reject its corporeal nature or eliminate its resistance. Newton’s use of the term inertia provides no conclusive evidence for a late date as often claimed and his definition of gravitas is difficult to reconcile with a late one. (shrink)

ABSTRACTThe worksheets that presumably contained Newton's early development of the fundamental concepts in his Principia have been lost. A plausible reconstruction of this development is presented based on Newton's exchange of letters with Robert Hooke in 1679, with Edmund Halley in 1686, and on some clues in the diagram associated with Proposition 1 in Book 1 of the Principia that have been ignored in the past. A graphical construction associated with this proposition leads to a rapidly convergent method to obtain (...) orbits for central forces, which elucidates how Newton may have have been led to formulate some of his most fundamental propositions in the Principia. (shrink)

These chapters analyze texts from Isaac Newton’s work to shed new light on scientific understanding at his time. Newton used the concept of “sensorium” in writings intended for a public audience, in relation to both humans and God, but even today there is no consensus about the meaning of his term. The literal definition of the Latin term 'sensorium', or its English equivalent 'sensory', is 'thing that feels’ but this is a theoretical construct. The book takes readers on a process (...) of discovery, through inquiry into both Newton’s concept and its underlying model. It begins with the human sensorium. This part of his concept is situated in the context of the aforesaid writings but also in the context of the writings of two of Newton's contemporaries, the physicians William Briggs and Thomas Willis, both of whom were at the forefront of their respective specialties of ophthalmology and neurology. Only once the human sensorium has been explored is it possible to generalize to the unobservable divine sensorium, because Newton's method of reasoning from experience requires that the second part of his concept is last in the order of knowledge. And the reason for this sequence is that his method, the short-hand term for which is 'analogy of nature', proceeds from that which has been observed to be universally true to that which is beyond the limits of observation. Consequently, generalization passes insensibly into reasoning by analogy. Readers will see how certain widespread assumptions can be called into question, such as that Newton was a theological voluntarist for whom the will is superior to the intellect, or that, for Newton, not only the world or universe but also God occupies the whole extent of infinite space. The insights afforded through this book will appeal to scholars of the philosophy of science, human physiology, philosophy of mind and epistemology, among others. (shrink)

Samuel Clarke is best known to historians of science for presenting Isaac Newton’s views to a wider audience, especially in his famous correspondence with G. W. Leibniz. Clarke’s independent writings, however, reveal positions that do not derive from, and do not coincide with, Newton’s. This essay compares Clarke’s and Newton’s ideas on the cause of gravity, with a view to clarifying our understanding of Newton’s views. There is evidence to suggest that Newton believed God was directly responsible for gravity, and (...) this interpretation has been promoted by a number of scholars. By comparing Newton’s views with those of Clarke, however, it can be seen that Newton did not subscribe to the kind of occasionalist approach to gravity that Clarke developed. Clarke insisted that matter was categorically incapable of being endowed with powers or forces and that therefore what looks like gravitational attraction has to be performed directly by God or by angels. By comparing Clarke’s pronouncements with Newton’s, it becomes clear that Newton adopted the more standard line: that the first cause, God, operated in nature through secondary causes and that gravitational attraction was just such a secondary (albeit occult) cause. (shrink)

Beginning with Berkeley and Leibniz, philosophers have been puzzled by the close yet ambivalent association in Newton's ontology between God and absolute space and time. The 1962 publication of Newton's highly philosophical manuscript De Gravitatione has enriched our understanding of his subtle, sometimes cryptic, remarks on the divine underpinnings of space and time in better-known published works. But it has certainly not produced a scholarly consensus about Newton's exact position. In fact, three distinct lines of interpretation have emerged: Independence: space (...) and time are not essentially related to God. Causation: space and time are caused by God. Assimilation: space and time are attributes of God. This paper defends the third interpretation against the first two by drawing out the under-appreciated influence of Descartes' metaphysics on Newton's ‘physico-theology’. (shrink)

In the Queries to the Latin version of the Opticks Newton claims that space is God’s sensorium. Although these passages are well-known, few commentators have offered interpretations of what Newton might have meant by these cryptic remarks. As is well known, Leibniz was quick to pounce on these passages as evidence that Newton held untenable or nonsensical views in metaphysics and theology. Subsequent commentators have largely agreed. This paper has two goals. The first is to offer a clear interpretation of (...) Newton’s claim about space and God’s sensorium by situating those claims within Newton’s philosophical thought. The second is to show how my interpretation rescues Newton from Leibniz’s critiques. I show that Newton had a considered position on the sensorium and the role it played in sensation and volition. The primary evidence for this comes from an experiment Newton performed involving after-images; an experiment he recorded in his student notebook and corresponded with Locke about. I also discuss Newton’s views on mind-body causation, divine extension, and divine analogy. My final position is that we should read Newton as claiming that space in the venue in which God exercises his divine will. I also consider the problem of the missing tanquam pointed out by Koyré and Cohen and propose a solution. (shrink)