This is the first full-length historical study of Gestalt psychology - an attempt to advance holistic thought within natural science. Holistic thought is often portrayed as a woolly-minded revolt against reason and modern science, but this is not so. On the basis of rigorous experimental research and scientific argument as well as on philosophical grounds, the Gestalt theorists Max Wertheimer, Wolfgang Kohler and Kurt Koffka opposed conceptions of science and mind that equated knowledge of nature with its effective manipulation and control. Instead, they attempted to establish dynamic principles of inherent, objective order and meaning, in current language, and principles of self-organization, in human perception and thinking, in human and animal behavior, and in the physical world. The impact of their work ranged from cognitive science to theoretical biology and film theory. Based on exhaustive research in primary sources, including archival material cited here for the first time, this study illuminates the multiple social and intellectual contexts of Gestalt theory and analyses the emergence, development and reception of its conceptual foundations and research programmes from 1890 to 1967.