ABSTRACT
How do I know that the man I am conversing with has a conscious mind? Well, he acts as if he is conscious of what I am saying, and when he puts out his cigarette and places it in a nearby ashtray, he acts as if he is conscious of his immediate surroundings. Yet all that I observe is his behavior, not what lies behind it. If my belief that the man is conscious were challenged, I could argue as follows: When I act in ways similar to the way the man acts, I really do understand and perceive; so, it is likely that he does too, and so he must be conscious. Although this sort of argument by analogy has often been challenged, it appears to give a reason for thinking that others are conscious even if the reason is only a weak one. How do I know that this same man has an unconscious mind? I cannot reason as before; I cannot reason from my own case to his because I am not conscious of my unconscious mind. How, then, can I determine whether he or I or anyone else has an unconscious mind? Some philosophers and psychologists have argued that we cannot, but many others, including Sigmund Freud, have disagreed.
