Article: Hobbes on Natural Philosophy as “True Physics” and Mixed Mathematics

Marcus P. Adams, ‘Hobbes on Natural Philosophy as “True Physics” and Mixed Mathematics’, Studies in History and Philosophy of Science, 56 (2016).

Abstract: In this paper, 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 corporePart 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.


Article: ‘Hobbes on the Scientific Study of the Human Mind’

Laurens van Apeldoorn: ‘Hobbes on the Scientific Study of the Human Mind’, Archiv für Geschichte der Philosophie, 97,3 (2015)

Abstract: This paper considers Hobbes’ scientific study of the human mind and the method that structures it. I argue that Hobbes approaches the mind – as he approaches the inanimate natural world – in accordance with the method of “physics” as set out in the fourth and last part of De Corpore. I discuss this method and show how and why it applies to the study of the human mind, in particular in his most famous exposition of the topic in Leviathan. This understanding of Hobbes’ method allows us to reconsider and reject a number of criticisms of his work: first, that Hobbes’ scientific study of the human mind is inconsistent because it also relies on introspection; second, that his approach fails because it is not, and cannot be, fully deductive, as a result of which the introduction of psychological concepts is unwarranted; and, finally, that his scientific study of the mind is superfluous because he never sufficiently shows it is important for his moral and political philosophy to understand the mind in accordance with the method of physics.