Nine themes help in understanding B.F. Skinner's development from graduate student in 1928 to the publication of his Behavior of Organisms in 1938. It is claimed that Skinner's primary personal development was from the role of precocious critic to mature theorist; that Skinner's discoveries of behavioral lawfulness enabled him to shed major portions of his earlier reflexological commitment; that his postulation of operants served several nonempirical functions; and that the postulation required that he depart from the restrictive philosophical framework in (...) which he had been working. (shrink)