In defense of definitions

The arguments of Fodor, Garret, Walker and Parkes [(1980) Against definitio ns, Cognition, 8, 263-367] are the source of widespread skepticism in cogni tive science about lexical semantic structure. Whereas the thesis that lexi cal items, and the concepts they express, have decompositional structure (i .e. have significant constituents) was at one time "one of those ideas that hardly anybody [in the cognitive sciences] ever considers giving up" (p. 2 64), most researchers now believe that "[a]ll the evidence suggests that th e classical [(decompositional)] view is wrong as a general theory of concep ts" [Smith, Medin & Rips (1984) A psychological approach to concepts: comme nts on Rey, Cognition, 17, 272], and cite Fodor ct al. (1980) as "sounding the death knell for decompositional theories" [MacNamara & Miller (1989) At tributes of theories of meaning, Psychological Bulletin, 106, 360]. I argue that the prevailing skepticism is unmotivated by the arguments in Fodor et al. Fodor ct al. misrepresent the form, function and scope of the decompos itional hypothesis, and the procedures they employ to test for the psycholo gical reality of definitions are flawed I argue, further, that decompositio nal explanations of the phenomena they consider are preferable to their pri mitivist alternatives, and, hence, that there is prima facie reason to acce pt them as evidence for the existence of decompositional structure. Cogniti ve scientists would, therefore, do well to revert to their former commitmen t to the decompositional hypothesis.