existential import a commitment to the existence of something implied by a sentence, statement, or proposition. For example, in Aristotelian logic (though not in modern quantification theory), any sentence of the form ‘All F’s are G’s’ implies ‘There is an F that is a G’ and is thus said to have as existential import a commitment to the existence of an F that is a G. According to Russell’s theory of descriptions, sentences containing definite descriptions can likewise have existential import since ‘The F is a G’ implies ‘There is an F’. The presence of singular terms is also often claimed to give rise to existential commitment. Underlying this notion of existential import is the idea – long stressed by W. V. Quine – that ontological commitment is measured by existential sentences (statements, propositions) of the form (Dv) f. See also ONTOLOGICAL COMMITMEN. G.F.S.