Another possible source of the intuitiveness of the Experience Requirement is that it arises when we compare the relatively sparse information content of occurrent thought to occurrent visual experience. Occurrent thought arguably is limited by the capacity of working memory, and it is well known that working memory constitutes a comparative bottleneck in the large context of human information processing (Sperling, 1960). Could this disparity between thought and experience (in terms of, for instance, complexity or informational content) even serve as a basis for the truth of the Experience Requirement? DeLancey (2007) and Schier (2008) have pursued defenses similar to the one just suggested.
(Both DeLancey and Schier seek to lend support (consistent with physicalism) to the intuition that Mary learns something upon seeing red. Central to both of their cases are comparisons between, on the one hand, visual experience, and, on the other hand, scientific theoretical understanding. DeLancey suggests that scientific understanding has a relatively low informational content (measured as Kolmogorov complexity). Schier suggests that scientific understanding is relatively impoverished for being, in her words, “fragmented.” It seems, however, from various examples discussed by both authors, that they are comparing visual experiences to the wrong sorts of mental entities: relatively impoverished occurrent states of working memory or language processing instead of vastly more capacious states of standing knowledge.)
However, I think that such a line of thought is ultimately mistaken. The mistake arises in treating phenomenal knowledge as a kind of occurrent thought. Phenomenal knowledge, like knowledge generally, is abeyant or standing. This fact about phenomenal knowledge is what allows us to retain our knowledge even under general anesthesia when we, presumably, have no occurrent mental states. Our standing conceptual knowledge, as argued above, is, from an information-theoretic point of view, enormously capacious, and more than adequate to the task of capturing the content of visual experience.
While it is mistaken to draw conclusions about what Mary can know from comparisons of occurrent thought and experience, if such mistaken experiences are widespread, then this fact can help to explain the widespread intuitiveness of the Experience Requirement. If, on the other hand, such comparisons are not widespread, we still have the previously discussed explanation at our disposal. People are drawn to the Experience Requirement because of a relatively rough grasp they have of the enormous bandwidth difference between vision and the other sensory modalities.
Concluding “Swamp Mary Semantics”
In this paper I have assumed physicalism and argued against gappy physicalism. The basis of my complaint is that, if it is possible for a Swamp Mary to have knowledge of phenomenal redness without herself having experienced red, then gappy physicalists have to supply an explanation of why it is that prerelease Mary would be phenomenally ignorant. I have argued further that, upon examining the various psychosemantic strategies for accounting for Swamp Mary’s knowledge, there is no basis for also maintaining prerelease Mary’s ignorance. Gappy physicalist may want to contemplate responding to my arguments by denying the possibility of Swamp Mary, but I am aware of no principled basis available for them to do so. I have offered that physicalists are better off just abandoning the intuition that prerelease Mary is phenomenally ignorant. In the service of making such an abandonment strategy more palatable, I have offered considerations designed to show why the key intuition behind the Mary thought experiment may have seemed plausible while nonetheless being false.