a priori. That which is prior to, or independent of, experience. In contrast, a posteriori refers to that which is dependent upon experience. These two terms are commonly used in epistemological discussions. The question of whether there are a priori or innate ideas, ones with which we are born rather than derive from the course of experience, has been contested from ancient to contemporary times. For empiricists, the human mind is at birth a tabula rasa (blank slate); for rationalists, we bring ideas to experience as well as derive them from it. The debate between empiricists and rationalists was at the center of Western philosophy during the modern epoch or period, with Kant often thought of as having 'resolved' it.