Epistemology Moralized: David Hume's Practical Epistemology

Hume Studies Volume 29, Number 2, November 2003, pp. 165-204 Epistemology Moralized: David Hume's Practical Epistemology MICHAEL RIDGE Among contemporary philosophers, even those who have not found skepticism about empirical science at all compelling have tended to find skepticism about morality irresistible. —Peter Railton1 Railton's remark is accurate; contemporary philosophers almost invariably suppose that morality is more vulnerable than empirical science to skepticism. Yet David Hume apparently embraces an inversion of this twentieth century orthodoxy.2 In Book 1 of the Treatise, he claims that the understanding, when it reflects upon itself, "entirely subverts itself" (T 1. 4.7.7; SBN 267) while, in contrast, in Book 3 he claims that our moral faculty, when reflecting upon itself, acquires "new force" (T 3.3.6.3; SBN 619). Such passages suggest Hume's view is that morality's claims on us are justified, whereas the understanding's claims are not—that skepticism about empirical science, but not morality, is irresistible. However, this interpretation does not accurately reflect Hume's position. Indeed, any interpretation which has Hume concluding that the understanding's claims on us are not justified faces an obvious worry—it makes nonsense of the rest of his naturalistic project, including, but not limited to, his description and justification of our moral faculty. For in defending his account of our moral faculty and, perhaps more Michael Ridge is Lecturer in Philosophy, University of Edinburgh, David Hume Tower, George Square, Edinburgh, EH8 9JX, United Kingdom, e-mail: mridge@staffmail.ed.ac.uk 166 Michael Ridge clearly, in arguing against those who believe in miracles, Hume inescapably presupposes that the understanding's claims on us are in some sense justified . In light of Hume's meticulous and enthusiastic pursuit of his larger naturalistic project, one might even be tempted to conclude that Hume never really thought his skeptical arguments were sound. It would, however, be a mistake to submit to this temptation—to do so would be to ignore the last part of Book 1 of the Treatise, in which Hume evidently does find such arguments to be sound. Hume is undeniably impressed by skepticism about the understanding, even though this skepticism appears to be in tension with the rest of his naturalistic project. There are three main ways of dealing with this apparent tension. I call these the "involuntarist," the "reductio," and the "practical," readings. The involuntarist reading emphasizes Hume's insistence that we cannot help but have certain beliefs, no matter how impressed we may be with skeptical arguments while in the study. Hume does pretty clearly think skeptical arguments cannot really phase us once we leave the study, so there is considerabe textual evidence for the involuntarist reading. Moreover, the involuntarist reading seems quite promising as a way to dissolve the apparent tension in his view. After all, if we cannot help but rely upon the understanding, it would be at best very odd, and at worst incoherent, to worry about whether we should refrain from relying upon it, since "ought" implies "can." Christine Korsgaard's interpretation is in the spirit of this approach. The reductio reading holds that Hume distinguishes two radically different conceptions of our cognitive faculties—the rationalist conception and his own. On this reading, Hume's skeptical arguments are offered in service of a reductio of the rationalist conception of the understanding, and not Hume's own conception. If this interpretation is right then Hume never really thought that the understanding, as we should conceive it, was subject to skeptical worries in the first place. Hence Hume could happily go on to rely upon the understanding as it should be conceived in carrying out the rest of his naturalistic project. The fact that the discredited rationalist conception of the understanding is vulnerable to devastating skeptical attacks would be irrelevant to the rest of his project. Annette Baier and Barbara Winters have defended the reductio reading.3 Finally, the practical reading maintains that while Hume defends the understanding, his defense is a practical one. The understanding's claims are justified, not because we can theoretically determine their correspondence to reality, but because relying on them is practically sensible. The end of Book...