In an application of phenomenological methodology to the ontology of semiotics, a semantic autonomism is proposed whereby a stratified conceptual structure of categories of field, event, and state is projected in parallel onto three semantic worlds derived from perception (W1), communication (W2), and imagination (W3). W2 is the unmarked member of this set, anchoring natural semantics in social interaction; lexicalization consists of the projection of conceptual structure onto Wl-3 to yield basic open class terms in each world: states (nouns) in Wl, events (verbs) in W2, and fields (adjectives) in W3. Discourse is based by default in W2 and can be switched among the worlds by implicit verbs (eg, 'see' and 'dream'), returning implicitly to W2 at its close. Nonbasic terms in each world are generated by mapping; mapping without switching underlies metaphor. Various discourse genres are related to the semantic world model. (Copyright 1994, Sociological Abstracts, Inc., all rights reserved.) (J. Hitchcock in LLBA 1994, vol. 28, n. 3)