Higher-Order Theories of Consciousness: An Overview

Explaining the nature of consciousness is one of the more important and perplexing areas in philosophy. What is consciousness? How is the conscious mind related to the body? Can consciousness be explained in terms of brain activity? How can we explain the sensation of the smelling of a rose or a conscious visual experience? Given that philosophy is interdisciplinary by its very nature, the problem of consciousness is also explored in such related fields as psychology and neuroscience. One question that should be answered by any viable theory of consciousness is: What makes a mental state a conscious mental state? That is, what transforms a nonconscious mental state into a conscious one? There is a long tradition that has attempted to understand consciousness in terms of some kind of higher-order awareness. For example, John Locke (1689/1975) once said that " consciousness is the perception of what passes in a man " s own mind. " This intuition and attempt to explain consciousness has been recently revived by a In general, the idea is that what makes a mental state conscious is that it is the object of some kind of higher-order representation (HOR). A mental state M becomes conscious when there is a HOR of M. A HOR is a " meta-psychological " state, i.e. a mental state directed at another mental state. So, for example, my desire to write a good introduction becomes conscious when I become " aware " of the desire. Intuitively, it seems that conscious states, as opposed to nonconscious ones, are the mental states that I am " aware of " in some sense. Any theory which attempts to explain consciousness in terms of higher-order states is known as a higher-order (HO) theory of consciousness. It is best initially to use the more neutral term " representation " because there are a number of different kinds of higher-order theory, depending upon how one characterizes the HOR-state in question. Moreover, to be clear, the sense of 'conscious state' that I have in mind is the same as Nagel's (1974) sense, i.e. there is 2 " something it is like to be in that state " from the subjective or first-person point of view. When I am, for example, having a conscious visual experience, there is something it " seems " or " feels " like from my first-person subjective perspective. The key to HO theories is …