Stewart Duncan

In the early years of the eighteenth century Leibniz had several interactions with John Toland. These included, from 1702 to 1704, discussions of materialism. Those discussions culminated with the consideration of Toland's 1704 Letters to Serena, where Toland argued that matter is necessarily active. In this paper I argue for two main theses about this exchange and its consequences for our wider understanding. The first is that, despite many claims that Toland was at the time of Letters to Serena a Spinozist, we can make better sense of him as a sort of Hobbesian materialist. The second main point concerns reasons for materialism, and in particular a story Locke tells in the Essay about materialists' motives. Toland defends his materialism by arguing that matter is active, and argues that matter is active by using a conceivability argument. But this is not the crude conceivability argument that Locke suggests motivates materialists. This (together with reflecting on some of Hobbes's arguments) suggests that we might well tell a Lockean story about reasons for early modern materialism, but not Locke's story.

Leibniz frequently uses the notion of expression, but it is not easy to see just how he understood that relation. This paper focuses on the particular case of the expression of God, which is prominent in the 'Discourse on Metaphysics'. The treatment of expression there suggests several questions. Which substances did Leibniz believe expressed God? Why did Leibniz believe those substances expressed God? And did he believe that all substances expressed God in the same way and for the same reasons? In answering those questions the paper distinguishes two views about expression in the 'Discourse', considers Leibniz's reasons for holding that substances express their causes, and argues that Leibniz's views about emanative causation are important for understanding the unity of his apparently distinct views here. The paper concludes by looking briefly at how the 'Discourse' fits into the evolution of Leibniz's views on this issue over time.

Leibniz's correspondence with Thomas Burnett of Kemnay is probably best known for Leibniz's attempts to communicate with Locke via Burnett. But Burnett was also, more generally a source of English intellectual news for Leibniz. As such, Burnett provided an important part of the context in which Locke was presented to and understood by Leibniz. This paper examines the Leibniz-Burnett correspondence, and argues against Jolley's suggestion that "the context in which Leibniz learned about Locke was primarily a theological one". That said, in thinking about Locke's Reasonableness of Christianity, and his subsequent defenses of it, Leibniz does offer an argument against Locke's book -- but not one that's closely related to Locke's theological views, or to any accusation of Socinianism. The paper also considers, by way of contrast, the way Leibniz and Burnett talk about the more obviously controversial figure John Toland.

Hobbes repeatedly expressed concerns about moral and political language, e.g., about the bad consequences of various uses and misuses of language. He did not simply focus on the consequences though. He also attempted to understand the problems, using the central semantic notion in his philosophy of language, signification. Hobbes, in both the Elements of Law and Leviathan, argues that a wide variety of terms – including ‘good’, ‘bad’, and the names of virtues and vices – have a double and inconstant signification. This paper explores and explains that theory of Hobbes's. (In the course of the discussion, two other interpretations of Hobbes's claims are discussed: Pettit’s discussion in terms of indexicals, and Alexandra’s in terms of sense and reference.) This phenomenon is, Hobbes thinks, pervasive in our use of moral and political language. Indeed he says his analysis applies to all “names of such things as affect us, that is, which please, and displease us” (Leviathan 4.24), which seems a very broad category indeed. This inconstancy of signification has considerable potential to cause confusion and conflict. Given those practical consequences, it is of some importance for Hobbes to find a solution to this problem. The paper examines several possible Hobbesian solutions to the problem. There is, however, reason to think that these suggested solutions cannot completely solve the problem. The paper concludes, then, by arguing that double and inconstant signification would always be a danger, even in a properly constituted Hobbesian commonwealth.

The notion of signification is an important part of Hobbes's philosophy of language. It also has broader relevance, as Hobbes argues that key terms used by his opponents are insignificant. However Hobbes's talk about names' signification is puzzling, as he appears to have advocated conflicting views. This paper argues that Hobbes endorsed two different views of names' signification in two different contexts. When stating his theoretical views about signification, Hobbes claimed that names signify ideas. Elsewhere he talked as if words signified the things they named. Seeing this does not just resolve a puzzle about Hobbes's statements about signification. It also helps us to understand how Hobbes's arguments about insignificant speech work. With one important exception, they depend on the view that names signify things, not on Hobbes's stated theory that words signify ideas. The paper concludes by discussing whether arguments about insignificant speech can provide independent support for Hobbes's views about other issues, such as materialism.

Debates in Modern Philosophy: Essential Readings and Contemporary Responses provides an in-depth, engaging introduction to important issues in modern philosophy. It presents 13 key interpretive debates to students, and ranges in coverage from Descartes' Meditations to Kant's Critique of Pure Reason. -/- Debates include: -/- Did Descartes have a developed and consistent view about how the mind interacts with the body? Was Leibniz an idealist, or did he believe in corporeal substances? What is Locke's theory of personal identity? Could there be a Berkeleian metaphysics without God? Did Hume believe in causal powers? What is Kant's transcendental idealism? -/- Each of the thirteen debates consists of a well known article or book chapter from a living philosopher, followed by a new response from a different scholar, specially commissioned for this volume. Every debate is prefaced by an introduction written for those coming upon the debates for the first time and followed by an annotated list for further reading. The volume starts with an introduction that explains the importance and relevance of the modern period and its key debates to philosophy and ends with a glossary that covers terms from both the modern period and the study of the history of philosophy in general. -/- Debates in Modern Philosophy will help students evaluate different interpretations of key texts from modern philosophy, and provide a model for constructing their own positions in these debates.

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.

I discuss Hume's views about whether simplicity and generality are positive features of explanations. In criticizing Hobbes and others who base their systems of morality on self interest, Hume diagnoses their errors as resulting from a "love of simplicity". These worries about whether simplicity is a positive feature of explanations emerge in Hume's thinking over time. But Hume does not completely reject the idea that it's good to seek simple explanations. What Hume thinks we need is good judgment about when we are going too far in our search for simple explanations. These worries about simplicity are not unique to Hume. We can see versions of them in the work of Hutcheson, Smith, and Reid.

Thomas Hobbes was, rather famously, a nominalist. The core of that nominalism is the belief that the only universal things are universal names: there are no universal objects, or universal ideas. This paper looks at what Hobbes's views about universal names were, how they evolved over time, and how Hobbes argued for them. The remainder of the paper considers two objections to Hobbes's view: a criticism made by several of Hobbes's contemporaries, that Hobbes's view could not account for people saying the same thing in different languages; and a more recently popular criticism of Hobbes, that his nominalism's reliance on similarity implicitly (and inconsistently) involves reliance on a universal.