ABSTRACT
The truths of reasoning are necessary, and their opposite is impossible. There are propositions that are necessarily true and such that, once one understands them, one sees that they are true. The properties or attributes that the proposition implies—those that would be instantiated if the proposition were true—must be properties or attributes that people can conceive or grasp. One cannot accept a proposition, in the sense in which people have been using the word "accept," unless one also understands that proposition. The traditional term for those a priori propositions which are "incapable of proof" is axiom. The terms "analytic" and "synthetic" were introduced by Kant in order to contrast two types of a priori proposition. An analytic judgment, according to Kant, is a judgment in which "the predicate adds nothing to the concept of the subject".
