Ramsey sentences are formal logical reconstructions of theoretical propositions attempting to draw a line between science and metaphysics. A Ramsey sentence aims at rendering propositions containing non-observable theoretical terms (terms employed by a theoretical language) clear by substituting them with observational terms (terms employed by an observation language, also called empirical language).
Ramsey sentences were introduced by the logical empiricist philosopher Rudolf Carnap. However, they should not be confused with Carnap sentences, which are neutral on whether there exists anything to which the term applies. [1]