 Perry replaced two essays from the original list with two others, one of which didn't exist at the earlier time.Because ERE is a collection of essays written over a period of time, and ultimately not selected or collated by their author, it is not a systematic exposition of his thought even though Perry suggests otherwise in his preface.This circumstance, in addition to the evolution of James own philosophic stance, has contributed to a wide variance in understanding, misunderstanding, and critical opinion of radical empiricism.