What place for the a priori published july 31 2011 michael j shaffer and michael l veber eds what place for the a priori open court 2011 261pp 4495 pbk isbn 9780812696608 reviewed by elijah chudnoff university of miami. Until the twentieth century it was more or less taken for granted that there was such a thing as a priori knowledge that is knowledge whose source is in reason and reflection rather than sensory experience with a few notable exceptions philosophers believed that mathematics logic and philosophy were all a priori. Before the 20th century the concept of a priori knowledge knowledge based in reason and reflection rather than experience found nearly universal acceptance by the early 20th century however philosophers were skeptical of the idea that there was any nontrivial existence of a priori knowledge. No place for the a priori michael devitt 2 evidence based psychotherapy values and the a priori edward erwin 3 the philosophical insignificance of a priori knowledge david papineau 4