Abstract
The development of the ego state paradigm (Berne, 1947/1968, 1957b/1977) marked the birth of transactional analysis. In this article, Berne's (1961, 1963) four principles of diagnosis are the basis of a schema that highlights the underlying unity of his definitions, diagrams, and case studies of ego states. Using Kuhn's (1970) approach to science, an analysis of Berne's cowpoke story (1957a/1977, 1957b/1977, 1961, 1963), and textual criticism of Bernian literature, the basics of ego state theory are schematized into four paradigms that give methodological consistency to structural analysis and help to classify ego state diagrams.