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.

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.

This paper discusses the materialist views of Margaret Cavendish, focusing on the relationships between her views and those of two of her contemporaries, Thomas Hobbes and Henry More. It argues for two main claims. First, Cavendish's views sit, often rather neatly, between those of Hobbes and More. She agreed with Hobbes on some issues and More on others, while carving out a distinctive alternative view. Secondly, the exchange between Hobbes, More, and Cavendish illustrates a more general puzzle about just what divided materialists from their opponents. Seemingly straightforward disagreements about whether incorporeal substances exist turn out to be more complex ones in which the nature of those things is disputed at the same time as their existence.

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.

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

Hobbes denies in Leviathan that we have an idea of God. He does think, though, that God exists, and does not even deny that we can think about God, even though he says we have no idea of God. There is, Hobbes thinks, another cognitive mechanism by means of which we can think about God. That mechanism allows us only to think a few things about God though. This constrains what Hobbes can say about our knowledge of God, and grounds his belief in a fairly strong version of the thesis that God is incomprehensible.

Leibniz's mill argument in 'Monadology' 17 is a well-known but puzzling argument against materialism about the mind. I approach the mill argument by considering other places where Leibniz gave similar arguments, using the same example of the machinery of a mill and reaching the same anti-materialist conclusion. In a 1702 letter to Bayle, Leibniz gave a mill argument that moves from his definition of perception (as the expression of a multitude by a simple) to the anti-materialist conclusion. Soon afterwards, in the Preface to the New Essays, Leibniz gave a different mill argument. That argument depends upon there being no arbitrary and inexplicable connections in nature, because God would not create such things. Later, in the 'Monadology', Leibniz again used the mill example in arguing against materialism. That passage too, I argue, uses an argument from inexplicability rather than from Leibniz's definition of perception

I consider Leibniz's thoughts about Hobbes's materialism, focusing on his less-discussed later thoughts about the topic. Leibniz understood Hobbes to have argued for his materialism from his imagistic theory of ideas. Leibniz offered several criticisms of this argument and the resulting materialism itself. Several of these criticisms occur in texts in which Leibniz was engaging with the generation of British philosophers after Hobbes. Of particular interest is Leibniz's correspondence with Damaris Masham. Leibniz may have been trying to communicate with Locke, but ended up discussing Masham's version of the argument for materialism that Leibniz attributed to Hobbes.

Margaret Cavendish (1623-73) held a number of surprising philosophical views. These included a materialist panpsychism, and some views in what we might call environmental ethics. Panpsychism, though certainly not unheard of, is still often a surprising view. Views in environmental ethics - even just views that involve a measure of environmental concern - are unusual to find in early modern European philosophy. Cavendish held both of these surprising views. One might suspect that panpsychism provides some reasons for environmental concern. I argue, however, that Cavendish did not derive her environmental ethics from her panpsychism. If there is a connection, it is a developmental one, leading from the ethics to the panpsychism. The investigation of these issues also provides an occasion for thinking more generally about how Cavendish's views fit together, and whether she developed a systematic philosophy in the manner of several of her contemporaries.

Early modern debates about the nature of matter interacted with debates about whether matter could think. In particular, some philosophers (e.g., Cudworth and Leibniz) objected to materialism about the human mind on the grounds that matter is passive, thinking things are active, and one cannot make an active thing out of passive material. This paper begins by looking at two seventeenth-century materialist views (Hobbes’s, and one suggested but not endorsed by Locke) before considering that objection (which I call here the Activity Argument). In discussion, I note that several philosophers of the time believed that matter was active. That view opens up a possible response to the Activity Argument. The paper concludes by looking at the views of two materialists of the time who also believed that matter was active, Toland and Cavendish.

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.

This paper investigates Locke’s views about materialism, by looking at the discussion in Essay IV.x. There Locke---after giving a cosmological argument for the existence of God---argues that God could not be material, and that matter alone could never produce thought. In discussing the chapter, I pay particular attention to some comparisons between Locke’s position and those of two other seventeenth-century philosophers, René Descartes and Ralph Cudworth. Making use of those comparisons, I argue for two main claims. The first is that the important argument of Essay IV.x.10 is fundamentally an argument about the causation of perfections. Indeed, Locke gives multiple such arguments in the chapter. My second main claim is that my proposed reading of IV.x is not merely consistent with what Locke says elsewhere about superaddition, but also provides reasons to favor a particular understanding of what superaddition is.

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.

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.

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.

Gassendi and Hobbes knew each other, and their approaches to philosophy often seem similar. They both criticized the Cartesian epistemology of clear and distinct perception. Gassendi engaged at length with skepticism, and also rejected the Aristotelian notion of scientia, arguing instead for a probabilistic view that shows us how we can move on in the absence of certain and evident knowledge. Hobbes, in contrast, retained the notion of scientia, which is the best sort of knowledge and involves causal explanation. He thought, however, that this sort of knowledge was only available in geometry and political philosophy.

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.

We look at some interesting and important episodes in the life of early modern Epicureanism, focusing on natural philosophy. We begin with two early moderns who had a great deal to say about ancient Epicureanism: Pierre Gassendi and Ralph Cudworth. Looking at how Gassendi and Cudworth conceived of Epicureanism gives us a sense of what the early moderns considered important in the ancient tradition. It also points us towards three main themes of early modern Epicureanism in natural philosophy, which we then discuss at greater length: atomism, materialism about the mind or soul, and the denial of providence, which was often accompanied by deflationary explanations of religious belief.

This chapter considers Ralph Cudworth as a philosophical critic of Hobbes. Cudworth saw Hobbes as a representative of the three views he was attacking: atheism, determinism, and the denial that morality is eternal and immutable. Moreover, he did not just criticize Hobbes by assuming that a general critique of those views applied to Hobbes’s particular case. Rather, he singled out Hobbes, often by quoting him, and argued against the distinctively Hobbesian positions he had identified. In this chapter I look at Cudworth as a critic of Hobbes in two of the three central areas, atheism and ethics, focusing on passages where we see him explicitly picking out Hobbes.

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.

Deborah Boyle's book is a splendid addition to the literature on the philosophy of Margaret Cavendish. It provides an overview of Cavendish's philosophical work, from her panpsychist materialism, through her views about human motivation and general political philosophy, to views about gender, health, and humans' relation to the rest of the natural world. Boyle emphasizes themes of order and regularity, but does not argue that there is a strong systematic connection between Cavendish's views. Indeed, she makes a point of noting the different ways in which the themes of order and regularity work in different areas of Cavendish's philosophy.The early chapters consider Cavendish's natural philosophy....

Thomas Hobbes often includes powers and abilities in his descriptions of the world. Meanwhile, Hobbes’s philosophical picture of the world appears quite reductive, and he seems sometimes to say that nothing exists but bodies in motion. In more extreme versions of such a picture, there would be no room for powers. Hobbes is not an eliminativist about powers, but his view does tend toward ontological minimalism. It would be good to have an account of what Hobbes thinks powers are, and how they fit into his understanding of the world. In this chapter, I investigate Hobbes’s account of the metaphysics of powers and abilities. Section 1 considers three important aspects of Hobbes’s account of powers: the connection between powers and causes; the modal aspects of powers; and the connection between powers and motions. Sections 2 and 3 then consider interpretive arguments about whether Hobbes identifies powers with underlying corporeal features.