I first sketched the higher-order-thought theory of consciousness toward the end of
an article about mind-body materialism, to help defuse the challenge consciousness
seems to pose for materialism. That brief discussion left many questions unaddressed,
and I set out to develop the theory in ‘‘Two Concepts of Consciousness,’’ reprinted
here as chapter 1. My main goal there was to show how the theory can handle our
pretheoretic intuitions, sometimes by predicting those intuitions and in other cases
by showing why intuitions that seem compelling are nonetheless erroneous.
I also came to see how the theory facilitates the fruitful investigation of the many
connections consciousness has with other mental phenomena. One group of connections
has to do with mental qualities. Discussions of consciousness often take off
from unquestioned assumptions about the nature of mental qualities, assumptions
that constrain subsequent theory and so make a mystery of consciousness. The appeal
to higher-order thoughts suggests ways to work in the opposite direction, using the
theory to point toward an account of mental qualities that conforms to both commonsense
ideas and scientific findings about qualitative consciousness. In doing this,
the theory helps undermine the assumptions about mental qualities that cause difficulty.
These matters are the focus of chapters 5, 6, and 7.
A second group of issues has to do with the ways consciousness interacts
with thought, speech, and the self-interpretation that thoughts about ourselves
sometimes involve. The appeal to higher-order thoughts makes possible informative
explanations of things that it’s unlikely any other theory can handle, such as why a
state’s being conscious coincides with its being reportable, why thoughts are always
conscious when they’re expressed verbally, and why our consciousmental lives appear
unified. Such topics dominate a number of the remaining chapters.
I am grateful to many friends, colleagues, and students for fruitful conversations
about the issues discussed here, and especially to Ned Block, Austen Clark, Martin
Davies, Dan Dennett, Zolt´an Dienes, Jerry Fodor, Pierre Jacob, Tony Marcel,
Douglas Meehan, Sidney Morgenbesser, Adam Morton, Josef Perner, Georges Rey,
Edmund Rolls, Peter Ross, Eckart Scheerer, Robert Schwartz, Sydney Shoemaker,
Josh Weisberg, and Larry Weiskrantz. And I am grateful to David Pereplyotchik for
preparing the index and for very many helpful comments.