do not reside "within" the mind as if the mind were a space in which these dispositions could be placed or located. Furthermore, dispositions are not the same as behavioral actions, but actions may be explained by dispositions. Dispositions are neither visible nor hidden, because they are not in the same logical category as behavioral actions. Dispositions are not mental processes or intellectual acts, they are propensities which explain various modes of behavior. Perceptions, thoughts, emotions, and feelings may be understood as observable behaviors which have various modes of production. Ryle admits that his approach to the theory of mind is behavioristic in being opposed to the theory that there are hidden mental processes that are distinct from observable behaviors. His approach is based on the view that actions such as thinking, remembering, feeling, and willing are revealed by modes of behavior or by dispositions to modes of behavior. At the same time, however, he criticizes both Cartesian theory and behaviorist theory for being overly mechanistic. While Cartesian theory may insist that hidden mental events produce the behavioral responses of the conscious individual, behaviorism may insist that stimulus-response mechanisms produce the behavioral responses of the conscious individual. Ryle concludes that both Cartesian theory and behaviorist theory may be too rigid and mechanistic to provide us with an adequate understanding of the concept of mind. Category mistakes As a linguistic philosopher, a significant portion of Ryle's argument is devoted to analyzing what he perceives as philosophical errors based in conceptual use of language. His critique of Cartesian dualism refers to it as a category mistake. Category mistakes, such as the ones Ryle points out, are made by people who do not know how to properly wield the concepts with which they are working. Their puzzles arise from the inability to use certain items in human language. A much-cited example is of a foreign visitor being shown round Oxford (which has no campus) and after having been shown colleges, libraries, laboratories and playing fields asks in puzzlement "But where is the university?" The answer is, of course, all of these. The theoretically interesting category mistakes are those made by people who are perfectly competent to apply concepts, at least in the situations with which they are familiar, but are still liable in their abstract thinking to relocate those concepts to logical types to which they do not belong. The dualist doctrine establishes