<philosophical terminology> what is implicitly involved in making an assertion. Hence, according to P.F. Strawson, a presupposition is a necessary condition for either the truth or the falsity of the statement that presupposes it. Thus, for example, "My grand-daughter is a smart baby" - whether or not she exhibits intelligent behavior - presupposes that I do, in fact, have at least one female grand-child. Recommended Reading: Douglas N. Walton, Argumentation Schemes for Presumptive Reasoning (Erlbaum, 1995); Nirit Kadmon, Formal Pragmatics: Semantics, Pragmatics, Presupposition, and Focus (Blackwell, 2001); and Gennaro Chierchia, Dynamics of Meaning: Anaphora, Presupposition, and the Theory of Grammar (Chicago, 1995).
[A Dictionary of Philosophical Terms and Names]
Try this search on OneLook / Google