David Rosenthal

It’s often held that undetectable inversion of mental qualities is, if not possible, at least conceivable. It’s thought to be conceivable that the mental quality your visual states exhibit when you see something red in standard conditions is literally of the same type as the mental quality my visual states exhibit when I see something green in such circumstances. It’s thought, moreover, to be conceivable that such inversion of mental qualities could be wholly undetectable by any third-person means. And since first- person access is limited to a single individual, and so could not reveal a disparity in mental quality between us, third-person undetectability means undetectability tout court

No mental phenomenon is more central than consciousness to an adequate understanding of the mind. Nor does any mental phenomenon seem more stubbornly to resist theoretical treatment. Consciousness is so basic to the way we think about the mind that it can be tempting to suppose that no mental states exist that are not conscious states. Indeed, it may even seem mysterious what sort of thing a mental state might be if it is not a conscious state. On this way of looking at things, if any mental states do lack consciousness, they are exceptional cases that call for special explanation or qualification. Perhaps dispositional or cognitive states exist that are not conscious, but nonetheless count as mental states

Ned BlockÕs influential distinction between phenomenal and access consciousness has become a staple of current discussions of consciousness. It is not often noted, however, that his distinction tacitly embodies unargued theoretical assumptions that favor some theoretical treatments at the expense of others. This is equally so for his less widely discussed distinction between phenomenal consciousness and what he calls reflexive consciousness. I argue that the distinction between phenomenal and access consciousness, as Block draws it, is untenable. Though mental states that have qualitative character plainly differ from those with no mental qualities, a mental stateÕs being conscious is the same property for both kinds of mental state. For one thing, as Block describes access consciousness, that notion does not pick out any property that we intuitively count as a mental stateÕs being conscious. But the deeper problem is that BlockÕs notion of phenomenal consciousness, or phenomenality, is ambiguous as between two very different mental properties. The failure to distinguish these results in the begging of important theoretical questions. Once the two kinds of phenomenality have been distinguished, the way is clear to explain qualitative consciousness by appeal to a model such as the higher-order-thought hypothesis. Ó 2002 Elsevier Science . All rights reserved

In Descartes's time the issue between materialists and their opponents was framed in terms of substances. Materialists such as Thomas Hobbes and Pierre Gassendi maintained that people are physical systems with abilities that no other physical systems have; people, therefore, are special kinds of physical substance. Descartes's DUALISM, by contrast, claimed that people consist of two distinct substances that interact causally: a physical body and a nonphysical, unextended substance. The traditional

According to Dennett, the facts about consciousness are wholly fixed by the effects consciousness has on other things. But if a mental state's being conscious consists in one's having a higher-order thought about that state, we will in principle have an independent way to fix those facts. Dennett also holds that our speech acts sometimes determine what our thoughts are, since speech acts often outrun in content the thoughts they express.I argue that what thoughts we have is independent of how we express them in speech, and that this is consonant with speech acts’ often seeming to have more fine grained content than the thoughts they express. This model has the advantage, compared with Dennett’s, of accommodating our folk-psychological taxonomy of intentional states and preserving the traditional idea that speech acts express antecedent intentional states. Speech acts doubtless do sometimes have richer content than the thoughts they express, though sometimes verbally expressing a thought simply makes us conscious in a more fine-grained way of what that content is.On the higher-order-thought model, as on Dennett’s, a mental state’s being conscious is, in effect, our spontaneously interpreting ourselves as being in that state. But such spontaneous self-interpretation need not be the last word on what content our thoughts have. Even though the content of speech acts sometimes outrun that of the thoughts they express, we can explain why the two seem always to be exactly the same. Even when a speech act is richer in content than the thought it expresses, the well-entrenched pragmatic equivalence between saying something and saying that one thinks that thing ensures that one will be conscious of one’s thought as having the richer content of the speech act that expresses it. We are conscious of our thoughts as having the content that our speech acts would capture.