Access to the full content is only available to members of institutions that have purchased access. If you belong to such an institution, please log in or find out more about how to order.


A priori

DOI: 10.4324/9780415249126-P001-2
Version: v2,  Published online: 2011
Retrieved July 23, 2024, from

Article Summary

An important term in epistemology since the seventeenth century, ‘a priori’ typically connotes a kind of knowledge or justification that does not depend on evidence, or justification, from sensory experience. Talk of a priori truth is ordinarily shorthand for talk of truth knowable or justifiable independently of evidence from sensory experience; and talk of a priori concepts is usually talk of concepts that can be understood independently of reference to sensory experience. A priori knowledge contrasts with a posteriori knowledge, knowledge requiring evidence from sensory experience. Broadly characterized, a posteriori knowledge is empirical, experience-based knowledge, and a priori knowledge is nonempirical knowledge. Standard examples of a priori truths are the truths of mathematics, whereas standard examples of a posteriori truths are the truths of the natural sciences.

Citing this article:
Moser, Paul K.. A priori, 2011, doi:10.4324/9780415249126-P001-2. Routledge Encyclopedia of Philosophy, Taylor and Francis,
Copyright © 1998-2024 Routledge.

Related Articles