Kant’s book Critique of Pure Reason, written in 1781 had created a revolution in the world of Philosophy. Before Kant the prevalent judgments were Analytic a priori ‘All bachelors are unmarried males’, whose truth was justified by mere conceptual analysis through reason, and Synthetic a posteriori ‘The leaves are green’ whose truth was justified by sense experience. Analytic a posteriori was refuted due to its absurdity and Synthetic a priori was considered impossible. But Kant first showed that Synthetic a priori judgments are possible. Before Kant it was believed: No Analytic propositions are a posteriori. (E) On logically converting it we get: No a posteriori propositions are Analytic (E), on obverting it we get: All a posteriori propositions are non-analytic or are synthetic (A). On further conversion we get: Some synthetic propositions are a posteriori. (I)