Hume, Kant, and the Sea of Illusion

Hume Studies Volume 29, Number 1, April 2003, pp. 63-88 Hume, Kant, and the Sea of Illusion PETER THIELKE Given Hume's seemingly ambivalent—and often cryptic—claims about the limits of human knowledge, it is no surprise that a skeptical and a naturalistic reading compete as the proper interpretation of the Treatise. Although Hume was traditionally viewed as a skeptic, more recently the "naturalized" view of the Treatise has been in the ascendancy.1 On this view, while Hume deploys various skeptical arguments, they are mainly in the service of revealing the essentially naturalistic structure of human cognition.2 In other words, Hume is taken to be engaged in a type of philosophical psychology, and the results of this project are taken to accord with generally naturalized claims about the mind. In this paper, however, I want to take issue with this "naturalized" version of Hume, and instead try to show not only that Hume's skepticism is an ineliminable feature of his view, but that in fact Hume's skepticism in the Treatise is complicit with his naturalism.31 propose to do this by enlisting help from what might initially seem to be an unlikely quarter: Kant's Critique of Pure Reason, and specifically the doctrine of illusion found in the Transcendental Dialectic.4 Both Kant and Hume, I will argue, come to realize that human reason is fraught with illusion—and, in fact, that this illusion is in an important sense natural. Moreover, both Kant and Hume distinguish between the natural illusions that characterize human reason and the errors that follow from succumbing to these illusions. But where Kant's transcendental idealism claims to find a corrective to these errors, Hume, I will argue, finds Peter Thielke is Assistant Professor of Philosophy, Pomona College, Pearsons Hall, 551N. College Avenue, Claremont, CA 91711, USA. e-mail: Peter.Thielke@pomona.edu 64 Peter Thielke no such safe haven. For this reason he remains—in the Treatise, at least— unable to avoid skeptical worries. And, more importantly, this skepticism follows from a "natural" feature of the mind.5 I. The Island of Truth: Transcendental Illusion in the Critique At the start of the section on "Phenomena and Noumena," Kant offers one of the rare metaphors in the Critique. The territory of pure understanding, he notes, is an island, and enclosed in unalterable boundaries by nature itself. It is the land of truth (a charming name), surrounded by a broad and stormy ocean, the true seat of illusion, where many a fog bank and rapidly melting iceberg pretend to be new lands, and, ceaselessly deceiving with empty hopes the voyager looking around for new discoveries , entwine him in adventures from which he can never escape and yet also never bring to an end.6 Much of the work of the Critique can be seen as providing an accurate map of this "land of truth." As Kant's surveying reveals, the domain of the pure understanding is fundamentally limited: the possibility of experience traces the coastline of the island of the pure understanding, beyond which we find only stormy metaphysical seas.7 Given this description of the dangers of speculative metaphysics, it seems rather odd that Kant suggests that the turbulent ocean must be explored. The philosophical seafarer is inexorably drawn to the sea of illusion, to the "adventures from which he can never escape and yet also never bring to an end." It is just this enterprise that provides the focus of the Transcendental Dialectic , which examines the transcendental illusions that Kant claims attend any attempt to find sure ground apart from the island of the pure understanding. An illusion, Kant holds, arises from the illegitimate use of a cognitive faculty , either by the exercise of some undue influence upon it, or by the extension of its principles beyond their purview. Illusion is transcendental, Kant notes, when it concerns the demands of reason, which illegitimately transform what are merely subjectively necessary connections into objective claims about things in themselves. The drive of reason, in other words, seduces us into extending the categories of the pure understanding beyond their appropriate empirical employment, and deceives us into applying these categories to transcendent...