Originally published in 1978, the main task of this book was to consider the psychology of thinking in relation to the various perspectives from which thought processes were studied at the time. It provided an up-to-date and critical evaluation of current experimental studies of thinking organized within a framework which reflects the separate theoretical orientations and methodologies through which these investigations are carried out. This approach will help the reader to become aware of the complex relationship between the theoretical orientations, the problems selected for investigation and the methods used for studying them. An important underlying theme of the book concerns the relationship between the activities of the thinker and the demands of his environment. As far as is known, this was the only textbook on thinking to deal with the subject matter specifically in terms of theoretical approaches and methods of investigation at the time.