In Treatise 1.4.2, David Hume seeks to explain how we come to believe in the external existence of bodies. He offers a complicated psychological account, where the imagination operates on the raw data of the senses to produce the ‘vulgar’ belief in the continued existence of the very things we sense. On behalf of philosophers, he presents a perceptual relativity argument that purports to show that the vulgar belief is false. I argue that scholars have failed to appreciate Hume's peculiar (...) formulation of the perceptual relativity argument and its relation to his psychological account of the vulgar belief. On my interpretation, in order to account for all the premises that Hume explicitly offers, the argument is best interpreted as beginning with a reductio that opposes the effects of the senses and the imagination in the vulgar belief. Thus Hume can be interpreted as identifying an ‘antinomy’ in the habits of the vulgar mind that produce belief in bodies. (shrink)

The categorial concepts of substance (thing) and substance (stuff) are described, and the conceptual relationships between things and their constitutive stuff delineated. The relationship between substance concepts, expressed by other count-nouns, and natural kind concepts is examined. Artefacts and their parts are argued to be substances, whereas parts of organisms are not. The confusions of seventeenth- and eighteenth-century philosophers who invoked the concept of substance are adumbrated.

This thesis investigates Hume’s philosophy of external existence in relation to, and within the context of, his philosophy of scepticism. In his two main works on metaphysics – A Treatise of Human Nature (1739–40) and the first Enquiry (first ed. 1748) – Hume encounters a predicament pertaining to the unreflective, ‘vulgar’ attribution of external existence to mental perceptions and the ‘philosophical’ distinction between perceptions and objects. I argue that we should understand this predicament as follows: the vulgar opinion is our (...) natural and default belief for Hume, but causal reasoning reveals it to be false, and the philosophical alternative is a confabulation that we cannot permanently believe and is devoid of justification. Hume uses the fact that we cannot have a satisfactory account of belief in external existence as a sceptical consideration to motivate his wider philosophical scepticism. Hume’s response to his predicament about external existence is found in the context of his confrontation with other sceptical worries (Treatise 1.4.7 and Enquiry 12), in which Hume also reflects generally on the nature and implications of scepticism. I argue that we should characterise Hume’s position as residually sceptical. This means that, while Hume accepts the unanswerability of some sceptical problems, he denies that it is possible to eradicate all belief as a result (and denies that it is practically useful to even try) and instead uses sceptical problems as a motivation to adopt a moderately sceptical position. While we inevitably return to entertaining the vulgar belief, there is no solution to the sceptical predicament; Hume does not endorse the vulgar belief, or the philosophical system, or indeed any alternative system of the external world that might extinguish the predicament. Sceptical doubt, for Hume, does not derail intellectual pursuits, but rather modifies our attitudes in those very pursuits. (shrink)