This systematic analysis of the nature and development of Talcott Parson's theory of action offers first an introduction to the conceptual paradigm upon which this theory is based - an introduction, that is, which will make Parson's writing more easily accessible. Second, the book gives an explanation of the development which the action theory has undergone during the half-century of Parson's career. Using a scheme of four theory-levels, the author indicates the crucial premises that can be distilled from Parson's early works. He argues that Parsons, from the very start of his career, was trying to translate abstract premises into a systematically constructed conceptual scheme. The first conceptual translation, however, turned out to be vague and inconsistent in many respects, and this study offers a very specific explanation of the inadequacy of this first (structural-functional) version of the theory of action. Dr Adriaansens argues that it was not until Parsons had found his way out of this 'conceptual dilemma' that the premises of the action theory could be adequately translated into a conceptual paradigm.