Abstract

My thesis is that there are no good reasons to think that none of the senses of morphemes of natural language are decompositionally complex, and several good reasons to think that most of them are, and that this fact has important consequences for several areas in philosophy. ;The philosophical interest of decompositionality lies in the explanatory role it has been taken to play in the theories of logic and language. Complex word meanings are traditionally supposed to constitute a source of explanation of certain informally valid inferences, as well as of certain coreference relations. ;Most contemporary philosophers of language are inclined to reject decompositionality. Assuming the anti-decompositional arguments of Wittgenstein, Quine and Putnam to have been successfully rebutted by Jerrold Katz, I focus on the systematic attack on semantic decomposition in Fodor, Garrett, Walker and Parkes' paper "Against Definitions." I argue that Fodor, et al. misrepresent the function, form and scope of decompositional theories, and that the psycholinguistic test procedures they take to show that decompositional structure is not psychologically real are flawed. ;I then argue that decompositional theories can account for the semantics of a large class of non-conjunctive modifier-head constructions--e.g., 'plastic flower'--that cannot be explained using either the apparatus of possible-worlds or thematic roles, or pragmatic principles of non-literal utterance interpretation. I then develop a decompositional account of these expressions within Jerrold Katz's formal semantic theory. ;Assuming identity of the senses of words and the content of term-sized mental representations , I also argue that non-decompositional semantic theories issue in highly implausible versions of the innateness hypothesis , on which all possible lexical concepts are innate. Decompositional theories, in contrast, provide a basis for a plausible nativism, on which only a relatively small number of primitive concepts need be supposed innate. I also argue that causal theories of content are inconsistent with a robust nativism. ;I conclude that contemporary philosophy of logic, language and mind must be substantially revised to accommodate the decompositional facts of natural language