A review of the psychiatric literature dealing with paranoia and the paranoid disorders1 reveals the fact that most of the writings on the subject, with a few notable exceptions, may be divided into two main groups. The earlier writers used a descriptive approach and concerned themselves chiefly with distinctions between supposed nosologic entities, while later authors, who preferred an interpretative method, often reached their conclusions after an intensive study of only a few cases. Rarely was attention given to paranoid reactions occurring outside the major functional paranoid psychoses, save for the purpose of drawing fine diagnostic distinctions. With the tendency, on the one hand, to classify and reclassify every deviation of symptom patterns from an arbitrary norm and the tendency, on the other, to make each case the basis not only for a new theory of etiology, but sometimes for a cosmogony as well, it is not surprising that