 Stich (1983) argues that cognitive psychology does not (or, in any case, should not) taxonomize mental states by their semantic properties at all, since attribution of psychological states by content is sensitive to factors that render it problematic in the context of a scientific psychology. Cognitive psychology seeks causal explanations of behavior and cognition, and the causal powers of a mental state are determined by its intrinsic “structural” or “syntactic” properties. The semantic properties of a mental state, however, are determined by its extrinsic properties – e.g., its history, environmental or intramental relations. Hence, such properties cannot figure in causal-scientific explanations of behavior. (Fodor 1994 and Dretske 1988 are realist attempts to come to grips with some of these problems.) Stich proposes a syntactic theory of the mind, on which the semantic properties of mental states play no explanatory role. (Stich has since changed his views on a number of these issues. See Stich 1996.)