Sartre opens "The Pursuit of Being", his Introduction to Being and Nothingness, noting that "considerable progress" can be found in a recent development of "modern thought". What is in question is a new manner — presumably, new at least since Berkeley — of "reducing the existent to the series of appearances which manifest it". Sartre makes it clear that further refinement is in order. But the new approach has at least the advantage of replacing, or promising to replace, some objectionable dualisms with a "monism of the phenomenon" (3/11).¹