In both logic and epistemology, the distinction (derived from Immanuel Kant) between statements whose predicate is included in the subject (analytic statements) and statements whose predicate is not included in the subject (synthetic statements). Some philosophers prefer to define as analytic all statements whose denial would be self-contradictory, and to define the term synthetic as meaning "not analytic." The distinction, introduced by Kant in The Critique of Pure Reason, aroused extensive debate in the mid-20th century, particularly in view of objections raised by W.V.O. Quine