Abstract

Ned Block’s Overflow Argument purports to establish that the neural basis of phenomenal consciousness is independent of the neural basis of access consciousness. In a recent paper, Block’s argument has been challenged by Peter Carruthers. Carruthers concedes the truth of one of the argument’s key steps, namely, that phenomenal consciousness overflows what is in working memory. At the same time, he rejects the conclusion of the argument by developing an account of this overflow that is alternative to Block’s. In this paper, I argue that Carruthers’s account does not pose a real threat to the Overflow Argument. The overall plausibility of Carruthers’s account rests on the empirical plausibility of a claim concerning global broadcasting which, albeit intuitively plausible in light of a lightly-sketched picture of the impact of attention upon neural matters, he offers no sufficient empirical evidence for. Drawing on some important imaging studies that reveal striking facts about neural responses to visual stimuli, I argue for two intimately related claims: first, that the intuitive plausibility of claims like Carruthers’s is not a guarantee of empirical plausibility; second, that as concerns the same claims, strong empirical evidence is needed before confident judgments of empirical plausibility can reasonably be formulated.