Equivalence and polyvalence: A case for the stratification of semantics

The article presents a semantic theory suggesting that equivalence and polyvalence are closely con­nected phe­nomena. The connection between them is utilised by making equivalence the basis of an argu­­ment for polyvalence within semantics, or in other terms, for a stratified semantics encompassing two levels of description. This argument from equivalence lends new support to frameworks assuming a strati­fied se­man­tics. For the argument to work properly, it is necessary to distinguish between equivalences that are facts of language and equi­valences that depend on extralinguistic circum­stances. A few other re­quire­ments for a coherent concept of equi­valence are also introduced. A major part of the article is devoted to an investiga­tion of previous accounts of equi­valence and of the conceptual underpinnings of these ac­counts. The investigation shows that all previous accounts have failed to make the necessary dis­tinction. Close examination of various cases of equivalence reveals differences that are cap­tured by the proposed dis­tinction, thus providing evidence for its ac­cu­racy. The article concludes that the argument from equi­valence strengthens the case for a stra­tified seman­tics pro­vided that the concept of equivalence has been ap­propriately delimited and defined.