An epistemological term referring to beliefs which depend upon previous experience (usually sensory experience). For example, the proposition "Bill is a bachelor" is known to be true only if we know who Bill is, and that he is indeed unmarried. Radical Empiricism maintain that ALL knowledge is a posteriori since knowledge is derived from the associations between ideas, and all ideas are derived from sensory experience. Without sensory experience there could be no ideas. Hence, all knowledge is a posteriori.