I offer an alternative account of the relationship of Hobbesian geometry to natural philosophy by arguing that mixed mathematics provided Hobbes with a model for thinking about it. In mixed mathematics, one may borrow causal principles from one science and use them in another science without there being a deductive relationship between those two sciences. Natural philosophy for Hobbes is mixed because an explanation may combine observations from experience (the ‘that’) with causal principles from geometry (the ‘why’). My argument shows (...) that Hobbesian natural philosophy relies upon suppositions that bodies plausibly behave according to these borrowed causal principles from geometry, acknowledging that bodies in the world may not actually behave this way. First, I consider Hobbes's relation to Aristotelian mixed mathematics and to Isaac Barrow's broadening of mixed mathematics in Mathematical Lectures (1683). I show that for Hobbes maker's knowledge from geometry provides the ‘why’ in mixed-mathematical explanations. Next, I examine two explanations from De corpore Part IV: (1) the explanation of sense in De corpore 25.1-2; and (2) the explanation of the swelling of parts of the body when they become warm in De corpore 27.3. In both explanations, I show Hobbes borrowing and citing geometrical principles and mixing these principles with appeals to experience. (shrink)

The status of the laws of nature in Hobbes’s Leviathan has been a continual point of disagreement among scholars. Many agree that since Hobbes claims that civil philosophy is a science, the answer lies in an understanding of the nature of Hobbesian science more generally. In this paper, I argue that Hobbes’s view of the construction of geometrical figures sheds light upon the status of the laws of nature. In short, I claim that the laws play the same role as (...) the component parts – what Hobbes calls the “cause” – of geometrical figures. To make this argument, I show that in both geometry and civil philosophy, Hobbes proceeds by a method of synthetic demonstration as follows: 1) offering a thought experiment by privation; 2) providing definitions by explication of “simple conceptions” within the thought experiment; and 3) formulating generative definitions by making use of those definitions by explication. In just the same way that Hobbes says that the geometer should “put together” the parts of a square to learn its cause, I argue that the laws of nature are the cause of peace. (shrink)

ABSTRACT Terrorism is perhaps the greatest challenge of the contemporary age. Of all the canonical figures in political theory, Thomas Hobbes is the most likely candidate to offer genuine insight into this problem. Yet although his analysis of the state of nature is immediately relevant to the diagnosis of this problem, his metaphysics cannot sustain his politics. His aspiration to “immutable” natural laws grounded in the universal motivation of the fear of death crumble when this fear is no longer universal. (...) When terrorists are inspired by a religious ideology that makes them willing to die for their beliefs—and when they benefit from other asymmetries with the civilian populations against which they are arrayed—Hobbes the theorist of war and international relations becomes less relevant than Hobbes the prescriber of “rational” (fearfully pacific) human nature. (shrink)

In this paper I would like to make a contribution to the debate on rights-talk and duties-talk relationship and priority by addressing the problem from a peculiar angle: that of moral conflicts and dilemma. My working hypothesis is that it should be possible to identify some basic and relevant normative features of rights-talk and duties-talk by observing how they modify the description of moral conflicts. I will try to show that both rights and duties posses original and irreducible normative features, (...) and that these latter can be employed in a general assessment of their pro and con. I will first show the conceptual relationship between rights and duties, analyzing in the process a deflationary argument for rights. Second, I will define the general features of moral conflict and dilemma. I will then analyze the different readings that can be given, taking rights or duties as standpoints, of two kinds of moral conflicts: «asymmetric» and «symmetric» conflicts. (shrink)

Within the paradigm of political liberalism, Hobbes’s legal philosophy has the peculiarity that individual property rights are treated as conditional and derived from the State’s absolute property rights, and thus common, State and individual property are explicitly recognised as three different juridical realities. Through determining the place that Hobbes’s few references to common property hold within his legal philosophy, it is possible to turn the thought of this classic author into a very useful theoretical tool for thinking the possibilities and (...) limits of a political strategy betting for common property against State property. (shrink)