The variables of quantification, 'something,' 'nothing,' 'everything,' range over our whole ontology, whatever it may be; and we are convicted of a particular ontological presupposition if, and only if, the alleged presuppositum has to be reckoned among the entities over which our variables range in order to render one of our affirmations true.
Willard Van Orman Quine (b. 1908), U.S. philosopher, logician. repr. in From a Logical Point of View (1953); also repr. In Semantics and Philosophy of Language, Linsky, Leonard (1952). "On What There Is," originally appeared in Review of Metaphysics (1948).
A fuller articulation of the author's cryptic slogan, "To be is to be the value of a variable," evidently purporting to explain not what there is but what a given author or speaker supposes there is.