UC Santa Barbara

The topic of this dissertation is the epistemology of 18th century Scottish philosopher David Hume. Hume notoriously pursues a constructive science of human nature in his masterpiece A Treatise of Human Nature while raising serious skeptical doubts about that project and leaving them apparently unanswered. In this dissertation, I attempt to answer one central question: what can Hume say in favor of believing anything beyond the present contents of one’s consciousness? The core of this dissertation is the identification of a theory of justification in Hume’s Treatise, one that preserves both his skepticism and his science of human nature. In Chapter 1, I introduce the interpretive problem that is the subject of this dissertation and survey proposed answers from a wide field of commentators. In Chapter 2, I explore Hume’s skepticism about reason and the role it plays in the epistemology of the Treatise. I argue that this skepticism generates an acute interpretive problem for Hume’s epistemology. This problem will in large part guide the discussion of justification in Hume’s Treatise in the following chapters. In Chapter 3, I look at Hume’s response to the self-undermining objection to his skeptical arguments against reason. I argue that Hume commits himself in his response to a dialectic of the flickering authority of reason. Reason loses and gains authority as often as the skeptical arguments gain and lose authority, respectively. Though this model of Hume’s response prima facie conflicts with other parts of the text, they can be made consistent by distinguishing between the flickering of reason and the mind’s response to this unstable position. In Chapter 4, I argue that Hume endorses two completely distinct standards of doxastic normativity: the epistemic and the natural (i.e. a belief’s contribution to psychological health). The epistemic grants beliefs philosophical approval, while the natural circumscribes the domain of investigation to prevent reasoning that leads to extreme skepticism. In Chapter 5, I develop a novel account of epistemic justification in the Treatise, which I call epistemic dispositionalism. Hume describes at least three doxastic dispositions: that of the vulgar, that of the true philosopher, and that of the extreme skeptic. A doxastic disposition is constituted by (i) active belief-forming principles, (ii) higher-order corrective tendencies, and (iii) emotional disposition. Epistemic justification, for Hume, reduces to the psychological feature of believability. A belief is epistemically justified if and only if it is believable within the philosophical or skeptical doxastic disposition and one is in that disposition. A belief is epistemically unjustified in all other cases (e.g. when believed within the vulgar disposition). In the skeptical disposition, it may be the case that the only ideas that are believable – and so justified – are those about one’s occurrent mental states. Shifts between dispositions are not directly under the control of the will, but can be precipitated by an increase or decrease in epistemological reflection. In Chapter 6, I apply the account of justification presented in Chapters 4 and 5 to the interpretive problem of Hume’s skepticism about reason identified in Chapter 2. We see that epistemic dispositionalism allows us to make sense of the dialectic of Hume’s skepticism about reason without highly controversial interpretations of his skeptical arguments or failing to explain his return to philosophy after the skeptical episode in the conclusion of Book 1.