Gilbert Ryle's book The Concept of Mind was published in 1949. According to Ryle, his "destructive purpose" was to show that "a family of radical category mistakes" is the source of the "official doctrine," that is, a "double-life theory," according to which "with the doubtful exception of idiots and infants in arms every human being has both a body and a mind." By numerous examples, Ryle showed quite forcefully how psychology and philosophy at the time were misled into asking the (...) wrong kinds of questions. More than 50 years have elapsed since the original publication of Gilbert Ryle's book and, as Ullin T. Place wrote shortly before passing away, Ryle's conceptual analysis is now due, if not overdue, for a comeback. The purpose of this paper is to discuss the persistent relevance of category mistakes to current problems in the analysis of behavior. (shrink)