Stewart Duncan

Language was central to Hobbes's understanding of human beings and their mental abilities, and criticism of other philosophers' uses of language became a favorite critical tool for him. This paper connects Hobbes's theories about language to his criticisms of others' language, examining Hobbes's theories of propositions and truth, and how they relate to his claims that various sorts of proposition are absurd. It considers whether Hobbes in fact means anything more by 'absurd' than 'false'. And it pays particular attention to Hobbes's categorization of causes of absurdity and of types of incoherent proposition, arguing that Hobbes's approach is only loosely related to later discussions of category mistakes.

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.