Is it possible to create a machine that can solve "all" the problems humans solve using their intelligence? This question defines the scope of what machines could do in the future and guides the direction of AI research. It only concerns the "behavior" of machines and ignores the issues of interest to psychologists, cognitive scientists and philosophers; to answer this question, it does not matter whether a machine is "really" thinking (as a person thinks) or is just "acting like" it is thinking.