  In 1892, Frege published his classic paper “On Sense and Reference”. This paper contains his first formulation of the distinction between sense (Sinn) and reference (Bedeutung). Roughly speaking, the sense of an expression is the mode of presentation of its referent, or the cognitive value of its referent. Expressions were said to express their senses. Sentences, too, had both referents and senses, according to Frege. The referent of a sentence is its truth-value. Its sense is a thought (Beaney 1997, p. 156), not a token thought, but a thought in the sense of a proposition: a sharable content. Thus, in Fregean jargon, meaningful sentences express thoughts.