This paper deals with Hobbes's theory of optical images, developed in his optical magnum opus, ‘A Minute or First Draught of the Optiques’, and published in abridged version in De homine. The paper suggests that Hobbes's theory of vision and images serves him to ground his philosophy of man on his philosophy of body. Furthermore, since this part of Hobbes's work on optics is the most thoroughly geometrical, it reveals a good deal about the role of mathematics in Hobbes's philosophy. (...) The paper points to some difficulties in the thesis of Shapin and Schaffer, who presented geometry as a ‘paradigm’ for Hobbes's natural philosophy. It will be argued here that Hobbes's application of geometry to optics was dictated by his metaphysical and epistemological principles, not by a blind belief in the power of geometry. Geometry supported causal explanation, and assisted reason in making sense of appearances by helping the philosopher understand the relationships between the world outside us and the images it produces in us. Finally the paper broadly suggests how Hobbes's theory of images may have triggered, by negative example, the flourishing of geometrical optics in Restoration England. (shrink)

This dissertation discusses the work of Thomas Hobbes, and has two main themes. The first is Hobbes's materialism, and the second is Hobbes's relationships to other philosophers, in particular his place in the mechanist movement that is said to have replaced Aristotelianism as the dominant philosophy in the seventeenth century. -/- I argue that Hobbes does not, for most of his career, believe the general materialist view that bodies are the only substances. He believes, rather, that ideas, which are our (...) main mechanism for thinking about the world, allow us to understand many bodies, but not to understand every thing we recognize to exist. The incomprehensible things include God---and, early in Hobbes's career, the human mind. Discussing materialism and our knowledge of God leads me to engage with the debate over Hobbes's alleged atheism. I argue that the evidence for Hobbes's atheism is weak at best. Hobbes is a sincere theist, though his view is sometimes unusual. -/- My discussion of Hobbes's relationships to other philosophers has three parts. In chapter five I argue that Hobbes's views about method are in important ways similar to Zabarella's. In chapter six I look at Hobbes's rejection of the view, held by some scholastic Aristotelians, that accidents can sometimes exist without inhering in substances. Thus we see two sides of Hobbes's interaction with the Aristotelian tradition. Sometimes that interaction is just rejection, but at other times Hobbes takes over views from that tradition. Then in chapter seven I consider whether, and in what sense, Hobbes is a mechanist. I argue that the narrative of mechanism and Aristotelianism is a less powerful explanation than it has seemed to some to be, because it is hard to see what mechanists have in common. (shrink)

This paper considers Margaret Cavendish's distinctive anti-mechanist materialism, focusing on her 1664 Philosophical Letters, in which she discusses the views of Hobbes, Descartes, and More, among others. The paper examines Cavendish's views about natural, material souls: the soul of nature, the souls of finite individuals, and the relation between them. After briefly digressing to look at Cavendish's views about divine, supernatural souls, the paper then turns to the reasons for Cavendish's disagreement with mechanist accounts. There are disagreements over the explanation (...) of particular phenomena, but also a broader disagreement over what to take as one's most basic causal model. (shrink)

Prior to 1651, Hobbes was agnostic about the existence of God. Hobbes argued that God’s existence could neither be demonstrated nor proved, so that those who reason about God’s existence will systematically vacillate, sometimes thinking God exists, sometimes not, which for Hobbes is to say they will doubt God’s existence. Because this vacillation or doubt is inherent to the subject, reasoners like himself will judge that settling on one belief rather than another is epistemically unjustified. Hobbes’s agnosticism becomes apparent once (...) we attend to his distinctions between the propositional attitudes one might adopt towards theological claims, including supposing, thinking, having faith and knowing. (shrink)