The term priori is a Latin phrase which means from the earlier. These are philosophical terms that was first made popular by Immanuel Kant in his first written work Critique of Pure Reason, published in the year 1787. The term is interpreted in several ways. Priori generally means the knowledge and wisdom attained through inferences, assumptions and conclusion rather than experimental evidences. Mathematical knowledge is a best example of priori as this is gained through the process of deduction achieved by reasoning.