CONSCIOUSNESS

1. Philosophy 65
consciousness in recent philosophy of mind. Those who take a higher-order approach to philosophical
theories of consciousness claim that to be in a conscious mental state is to have a
higher-order awareness of oneself as being in that state. The initial motivation for such an approach
is the alleged pretheoretical acceptability of what David Rosenthal calls the ‘Transitivity
Principle’: the claim that conscious mental states are those states we are conscious of being
in. It has been alleged, however (for instance, by Ned Block) that the intuitive acceptability
of the Transitivity Principle merely marks a linguistic connection between the locutions ‘conscious
state’ and ‘state one is conscious of’, and that there is no reason to suppose that such a
linguistic connection, even if it were analytic, provides a good starting-place for an empirical
theory of consciousness. In this paper, I discuss three possible sources of justification for
acceptance of the Transitivity Principle: phenomenological, conceptual/linguistic, and experimental.
I argue, following Uriah Kriegel, among others, that the main source of justification
for the Transitivity Principle for most of us is phenomenological rather than experimental or
conceptual: we accept the Transitivity Principle on the basis of first-person experience. The
immediate acceptability of the Transitivity Principle upon the slightest reflection might lead
one to suppose that the connection between conscious states and states that we are conscious
of is merely conceptual, but I argue that in reflecting on the Transitivity Principle, we engage
in an act of introspection, and that it is this act of introspection that motivates our acceptance
of the principle. In reflecting on our conscious mental states, we come to realize that consciousness
of those states always accompanies them. The status of the Transitivity Principle
is, then, that of a metaphysical claim about the necessary coextensiveness of ‘conscious state’
and ‘state one is conscious of’, initially based on a generalization from one’s own experience,
but easily supplemented by third-person considerations, and, one hopes, eventually, by scientific
investigation. It may seem that there is a difficulty with this proposal: if we have no way
to fix the reference of ‘conscious state’ except with the description ‘state one is conscious of’,
then the Transitivity Principle does after all turn out to express a linguistic triviality. I argue
against this objection that the meaning of ‘conscious state’ is constituted by a rich network of
connections to related notions such as the unconscious, reportability, subjective experience,
and the like. Thus, our discovery that it is of the nature of conscious states that we are conscious
of them is a genuine one. C2
52 Prefrontal Lesion Studies Cast Doubt on Higher-Order Theories of
Consciousness Benjamin Kozuch (Philosophy, Cognitive
Science, University of Arizona, Tucson, AZ)
In this talk, I will argue the following: A prediction of some higher-order (HO) theories of
consciousness is that brain areas in and around the prefrontal cortex are necessary for visual
consciousness; but lesions to these areas do not result in any loss of visual consciousness;
therefore, we have strong evidence against these HO theories of consciousness. HO theories
(as presented by Rosenthal, Kriegel, Carruthers, and others) hypothesize that a necessary
condition upon some mental state being conscious is that it be represented (in some suitable
way) by a HO state. Such theories are committed to there being some brain area(s) such that,
because they produce these HO representations, their normal operation is necessary to visual
consciousness. Let’s call these ‘integral’ areas. An important prediction of a HO theory, then,
is that lesioning of integral area(s) should cause a loss (to some degree) of visual consciousness.
It is probably only areas in and around the prefrontal cortex (PFC) that produce the
proper kinds of HO representations, as it is here that executive and monitoring functions are
carried out. But, as Pollen has pointed out, numerous studies have shown even bilateral lesions
to these areas to be not sufficient for causing a loss of visual consciousness. Among other
things, such subjects still experience ‘primary’ visual qualities like color. This is true even
in the case of lesions to the dorsolateral PFC, a brain area that some HO theorists (Kriegel,
Lau) have thought to produce the requisite kinds of HO representations. It seems, then, that an
important prediction of HO theories has not been met: When those brain areas that are likely
to produce the appropriate kinds of HO representations are lesioned, there is no loss of visual
consciousness. Here, the HO theorist can respond in various ways. I will consider what I take
to be the strongest responses. There are some experimental data (due to Lau, Dahaene, Del