Until recently, most philosophers have believed that if there is an answer to any philosophical question (or any other question of knowledge), it is either an empirical truth based on experience or an a priori truth that is both necessary and a product of reason.

Empirical Truth

A statement that is true because of the facts and knowable through experience.

A Priori Truth

Knowledge that is true independently of experience, known through reason alone.

Philosophical Question

A fundamental inquiry into the nature of reality, existence, knowledge, values, reason, mind, and language.