A priori knowledge is propositional knowledge that can be had without experience. It is usually contrasted with a posteriori knowledge, which requires experience. Mathematics and logic are usually considered a priori disciplines. The natural and social sciences are usually considered a posteriori disciplines.
... Louvain, and was admitted to the religious profession on October 7, 1860. Three years later he was sent to Hawaii, where he was ordained on May 24, 1864. On May 10 ...