Behavioral and Brain Sciences

Continuing Commentary
Jeffrey A. Gray (1995). The contents of consciousness: A neuropsychological conjecture. BBS 18:659–722.

The contents of consciousness: From C to shining C++

Michael H. Joseph a1 and Samuel R. H. Joseph a2
a1 Department of Psychology, Institute of Psychiatry, University of London, London SE5 8AF, United Kingdom [email protected]
a2 Centre for Cognitive Science, University of Edinburgh, Edinburgh EH8 9LW, United Kingdom [email protected]


We suggest that consciousness (C) should be addressed as a multilevel concept. We can provisionally identify at least three, rather than two, levels: Gray's system should relate at least to the lowest of these three levels. Although it is unlikely to be possible to develop a behavioural test for C, it is possible to speculate as to the evolutionary advantages offered by C and how C evolved through succeeding levels. Disturbances in the relationships between the levels of C could underlie mental illness, especially schizophrenia.