. Etymologically, ‘against belief’. Full-blooded paradoxes which affect the basis of logic exist when some statement needed for logic can apparently be both proved and disproved. Among them, paradoxes depending on purely logical or mathematical terms are called logical paradoxes, or paradoxes of set theory (e.g. RUSSELL’S PARADOX) while paradoxes depending on notions like meaning, designation, etc., are called semantic paradoxes (e.g. LIAR PARADOX); these are sometimes distinguished from the logical ones. In pragmatic paradoxes there is a contradiction not in what is said but in what is done in saying it. ‘It’s raining, but I don’t believe it is’ is not contradictory for both parts could be true. But uttering the second part frustrates the normal intention of uttering the first. Strategic paradoxes offer problems for how it is rational to act, claiming that each of two inconsistent policies can be defended as preferable to the other (NEWCOMB’S PARADOX, PRISONER’S DILEMMA). Other paradoxes claim e.g.
that apparently indispensable notions are inconsistent (e.g. ZENO’S PARADOXES), or that apparently possible situations are impossible (e.g. PREDICTION PARADOX). Loosely speaking a paradox may be little more than something odd or unexpected (e.g. material and strict IMPLICATION paradoxes). But how significant a given paradox is is often disputed. See also theory of TYPES.
T.Baldwin, G.E.Moore, Routledge, 1990. (See pp. 226–32 for discussion of ‘Moore’s paradox’, a pragmatic paradox.)
A.Pap, Semantics and Necessary Truth, Yale UP, 1958, chapter 9C (Types of paradox, especially pragmatic.)
