This is, indeed, the question, and in this chapter we will consider the nature of altered states in general, and drug induced states in particular.
James’s ‘other forms of consciousness’ would now be called ‘altered states of consciousness’ or ASCs, a concept that seems simple but is notoriously difﬁ cult to deﬁ ne. We get drunk and so feel and act differently; we let ourselves be hypnotised and cannot remember what we did; we sleep and dream and wake up to say ‘that was only a dream’. In all these cases something has obviously changed, but what? As soon as we start to think more deeply about altered states of consciousness the problems begin.