A study of the development of Freud's theory of anxiety has been presented, with emphasis on the relation of the anxiety theory to the clinical and general theoretical context of each phase of his work. The propositions involved in Freud's final formulations on anxiety are organized and summarized, and an attempt is made to integrate or eliminate earlier hypotheses, depending on their consistency with the eventual formulations. The effects of the discharge theory of affect are demonstrated in an effort to lay the groundwork for a more comprehensive psychoanalytic theory of anxiety within Freud's general framework.