Essays in Radical Empiricism by William James is a collection edited and published posthumously by his colleague and biographer Ralph Barton Perry in 1912. It was assembled from ten out of a collection of twelve reprinted journal articles published from 1904–1905 which James had deposited in August, 1906, at the Harvard University Library and the Harvard Department of Philosophy for supplemental use by his students. Perry replaced two essays from the original list with two others, one of which didn't exist at the earlier time.