Lexical decomposition meets conceptual atomism

Asking what can be a substantive word in natural language is closely related to asking what can be a lexical concept. However, studies on lexical concepts in cognitive psychology, philosophy and linguistics have little contact with each other. We argue i) that linguistic analyses of lexical items as grammatical structures do not map naturally to plausible models of the concepts corresponding to these lexical items and ii) that roots cannot encapsulate the conceptual content of a lexical item. Instead,we delineate a notion of syntactic root, distinct from that of morphological root: syntactic roots are name-tags, indices, establishing lexical identity for grammatical structures. This makes it possible to view basic lexical items as mappings between syntactically complex structures, identified by their root, with simplex concepts, where the constructional meaning of the former constrains the content of the latter. This can lead to predictive hypotheses about the possible content of lexical items in natural language.