Brie Gertler

The claim that there is an explanatory gap between physical and phenomenal properties is perhaps the leading current challenge to materialist views about the mind. Tye tries to block this challenge, not by providing an explanation to bridge the gap but by denying that phenomenalphysical identities introduce an explanatory gap. Since an explanatory gap exists only if there is something unexplained that needs explaining, and something needs explaining only if it can be explained , there is no gap. Tyes strategy differs crucially from the claim that identities never stand in need of explanation because they constitute ultimate explanations; for he allows that identities such as water = H?O are explainable. Unlike WATER and H?O, which are descriptive concepts, phenomenal concepts are perspectival and hence irreducible to descriptive concepts, according to Tye. The fact that something picked out by a perspectival concept is identical to something picked out by a non-perspectival concept cannot be explained.1 So, he concludes, phenomenalphysical identities need not be explained

When read as demands for justification, these questions seem absurd. We don’t normally ask people to substantiate assertions like “I think it will rain tomorrow” or “I have a headache”. There is, at the very least, a strong presumption that sincere self-attributions about one’s thoughts and feelings are true. In fact, some philosophers believe that such self-attributions are less susceptible to doubt than any other claims. Even those who reject that extreme view generally acknowledge that there is some salient epistemic difference between (a) one’s belief that she thinks it will rain tomorrow, or that she has a headache, and (b) her belief that it is raining, or that another person has a headache.

This paper calls into question the viability of materialist reduction of the phenomenal. I revisit the 'Knowledge Argument', which claims that there is information about the phenomenal which is not reducible to, nor even inferable from, information about the physical. I demonstrate the failure of the two chief strategies for blocking the Knowledge Argument: analyzing phenomenal knowledge as an ability, and construing it as knowledge of facts which are ontologically reducible to physical facts. Materialist reduction of the phenomenal is, thus, untenable; materialists must adopt a more extreme, eliminativist view about the phenomenal

In self-attributing beliefs and desires, we exploit a method that is different from our methods for attributing such states to others. On one traditional diagnosis, this difference stems from the subject’s exclusive access to introspective evidence. Gallois rejects the “access to evidence” model of the epistemic difference between self-knowledge and other-knowledge; in this ambitious book he provides a non-introspectivist alternative account of first-person authority. His intriguing proposal is that rational subjects can know their consciously held propositional attitudes without observing their own states. While he allows that we sometimes have introspective evidence for our own propositional attitudes, he is deeply suspicious about the power often accorded to such evidence. Robust conceptions of rationality and state consciousness weigh heavily in Gallois’ arguments and, I think, threaten to trivialize his claim that we enjoy first-person authority. But by departing from introspectivist accounts of self-knowledge, Gallois has made a provocative opening move in a gambit which promises to advance our understanding of the epistemic difference between self-knowledge and other-knowledge.

"Self-knowledge" is commonly used in philosophy to refer to knowledge of one's particular mental states, including one's beliefs, desires, and sensations. It is also sometimes used to refer to knowledge about a persisting self -- its ontological nature, identity conditions, or character traits. At least since Descartes, most philosophers have believed that self-knowledge is importantly different from knowledge of the world external to oneself, including others' thoughts. But there is little agreement about what precisely distinguishes self-knowledge from knowledge in other realms. Partially because of this disagreement, philosophers have endorsed competing accounts of how we acquire self-knowledge. These accounts have important consequences for the scope of mental content, for mental ontology, and for personal identity.

The definitive statement of the Knowledge Argument was formulated by Frank Jackson, in a paper entitled “Epiphenomenal Qualia” that appeared in The Philosophical Quarterly in 1982. Arguments in the same spirit had appeared earlier (Broad 1925, Robinson 1982), but Jackson’s argument is most often compared with Thomas Nagel’s argument in “What is it Like to be a Bat?” (1974). Jackson, however, takes pains to distinguish his argument from Nagel’s. This entry will follow standard practice in focusing on Jackson’s argument, though I will also describe the main points of alleged similarity and dissimilarity between these two arguments.

I elaborate and defend a set of metaphysical and epistemic claims that comprise what I call the acquaintance approach to introspective knowledge of the phenomenal qualities of experience. The hallmark of this approach is the thesis that, in some introspective judgments about experience, (phenomenal) reality intersects with the epistemic, that is, with the subject’s grasp of that reality. In Section 1 of the paper I outline the acquaintance approach by drawing on its Russellian lineage. A more detailed picture of the approach emerges in succeeding sections, which respond to a range of objections. Some critics charge that approaches of this sort are overly idealized, in that they ignore the cognitive flaws and limitations of actual human beings. I begin to address these worries in Section 2, by arguing that the epistemic commitments of the acquaintance approach are in fact relatively modest. In Section 3, I sketch a picture of introspective reference that explains how phenomenal reality can intersect with the epistemic in a phenomenal judgment, as the acquaintance approach requires. Drawing on this picture of introspective reference, Section 4 sets out a practical strategy for achieving knowledge by acquaintance. Some contemporary acquaintance theorists (BonJour 2003, Fumerton 1996) employ demanding epistemic standards for knowledge by acquaintance, standards beyond those mandated by the acquaintance approach. In Section 5 I show that instances of introspective knowledge that meet less demanding standards can satisfy the acquaintance approach’s epistemic commitments. The final sections concern the most direct challenges to the acquaintance approach, which target the claim that phenomenal reality intersects with the epistemic. According to one such challenge, this claim is belied by the fact that possessing a phenomenal concept is a matter of having certain dispositions. Section 6 draws on a discussion by Sosa (2003) to articulate this challenge, and responds to it on behalf of the acquaintance approach. Section 7 addresses Stalnaker’s (2008) worry that, if phenomenal reality intersected with the epistemic, phenomenal information would be incommunicable.