Abduction, Skepticism, and Indirect Realism

Moore and Russell thought that perceptual knowledge of the external world is based on abductive inference from information about our experience. Sosa maintains that this ‘indirect realist’ strategy has no prospects of working. Vogel disagrees and thinks it can and does work perfectly well, and his reasoning (and variations on that reasoning) seem initially promising, moreso than other approaches. My aim, however, will be to adjudicate this dispute in favor of Sosa’s pessimistic answer, and in doing so, to better uncover the important role abductive inference does have in a wider theory of perceptual knowledge, even if it doesn’t feature in any promising vindication of (anti-skeptical) indirect realism.