ABSTRACT
We all think we know the difference between being awake and being asleep but that is, among other things, the difference between two states of consciousness. When we wake up or go to sleep we have altered our state of consciousness. We can also alter our state of consciousness by taking drugs that lower our state of excitation or drugs that raise our state of excitation or drugs that are hallucinatory; or by exercising (endorphins), by falling in love or having sex, by meditating, by getting angry, by being in isolation or being inebriated, by fading out listening to a boring lecture or by getting enthusiastic about an exciting one. You can see that almost anything we do may involve changes in our state of consciousness.
