Wertheimer redefined psychology as the study of configurations or Gestalten. Like John Broadus Watson (1878-1936) with his behaviourism and at about the same time, Wertheimer rejected Wundt’s psychology, but for different reasons: he opposed Wundt’s atomism, considering that complex percepts could not be reduced to simple sensory elements. Gestalt psychology had its origins in perception but its ambit extended throughout the whole of psychology. Its precursors were to be found in Kant’s innate categories of space and time, in Mach’s emphasis on the analysis of experience, and in Brentano’s holistic mental experiences. Earlier von Ehrenfels had shown that the perception of musical tune was not dependent on the precise notes played as long as the Gestalt-qualities - the relations between the parts - were retained. Wertheimer extended this approach with a series of experiments on apparent movement, initially using Plateau’s phenakistoscope, and later a tachistoscope. It was the inability to distinguish between real and apparent motion that was taken as damning of any approach that explained perception in terms its sensations. Perception was holistic rather than atomistic. “There are wholes, the behaviour of which is not determined by that of their individual elements, but where the part-processes are themselves determined by the intrinsic nature of the whole. It is the hope of Gestalt theory to determine the nature of such wholes.” Not only was it said that the whole is more than its parts, but the perception of the whole is prior to that of its parts. Publication of the work on the phi phenomenon, in 1912, is taken as the origin of a new movement called Gestalt psychology. It was in the main stream of continental philosophy and used the methods of phenomenology as adumbrated by Goethe, Purkinje and Hering. Gestalt psychology was principally concerned with perception, and a range of robust demonstrations was devised to support its holistic nature. Wertheimer described many principles of perceptual organization, of which proximity, similarity, symmetry and good continuation were the principal ones. These were illustrated with sets of figures consisting of filled and open dots arranged in patterns which demonstrated the grouping principles. Much of the attraction of Gestalt psychology lay in the power of their perceptual demonstrations. Later Wertheimer applied a similar approach to the study of creativity in his Productive Thinking (1945). Wertheimer was born in Prague. He studied philosophy at the University of Prague, and psychology at the University of Berlin, where he met Koffka and Köhler. He obtained his doctorate from the University of Würzburg for his thesis on lie detection by means of word association. After returning to Berlin, he was called to the chair of psychology at the University of Frankfurt, but left for America in 1933 and took a position at the New School for Social Research. Some of the grouping principles are in operation in the pattern of filled and open dots which contains the portrait of Wertheimer. It could be said that the holes are different from some of the parts!