of twentieth century philosophy. 1. The question of the ontological status of consciousness The question 'What is consciousness?' is one of the most perplexing in philosophy-so perplexing that many have been motivated to proceed as though consciousness did not exist. If William James was speaking rhetorically when he said "Consciousness does not exist," 1 many behaviorists of the recent past were not. 2 James meant only to imply that consciousness is not an independently existing soul-substance, along­ side physical substances. He did not mean that we do not really 'have' consciousness, and he did not provide final resolution for the problem of the causal interrelations between consciousness and the physical realm (e. g. , our bodies). Many recent philosophers and psychologists, however, try to proceed as though these problems did not exist.