Dual Aspect Semantics

Abstract

Frege’s notion of sense plays (at least) two roles in his theory of meaning. One role concerns the relation between language and reality: an expression’s sense determines its reference. The other role relates a language to the mind of someone who understands it: to understand an expression is to grasp its sense. The dual role of sense is seen clearly in Frege’s account of the semantics of identity statements. The morning star = the evening star’ is true, since the sense of ‘the morning star’ and the sense of ‘the evening star’ determine the same reference. The sentence is cognitively significant, since it is possible for someone to know the senses expressed by the expressions ‘the morning star’ and ‘the evening star’ yet not know that they determine the same reference.