Wertheimer, originator of the Gestalt theory, was born in Prague, studied law at the universitythen became interested in psychology and philosophy. He obtained his Ph.D. at Wurzburg (1904) and during the following five years worked and studied at Prague, Vienna and Berlin. In 1909 he was appointed professor at Frankfurt, holding that position until 1933, when he accepted a post at the New School for Social Research in New York.Wertheimer is regarded as the founder of the Gestalt school of psychology, a movement which started as a protest against the structuralist attempt to explain complex experiences entirely in terms of elementary constituents. In contrast to this “atomistic” approach, the Gestalt theory holds that many of our perceptions and other experiences are unique wholes which cannot be reduced to their parts without destroying them, and cannot be predicted from a knowledge of the parts—just as the properties of water cannot be predicted from the properties of the two gases that combine to produce it.The origin of this movement can be traced to a specific event. In 1910 Wertheimer began to experiment on the perception of motion. Using a toy stroboscope as an instrument, he showed that when two objects are illuminated in rapid succession, the individual perceives a movement of one toward the other instead of two discrete objects. He reported this finding in 1912, and this date is usually regarded as the beginning of the movement. His demonstration of one type of apparent movement, the phi phenomenon as it was later called, is considered one of the crucial experiments in psychology, for it dramatically pointed up the inadequacy of the elementaristic view of experience, and showed that it actually analyzed movement out of existence. During the next few years, Wertheimer and two associates, Wolfgang Kohler and Kurt Koffka, attacked two other postulates of structuralism—the view that sensations are the elements of experience, and that their combination can be completely understood through the laws of association. Wertheimer characterized the latter view as a “bundle hypothesis,” and argued that perception is an integration which derives its character not merely from individual sensations but from the relationships between them. He attempted to explain the physical basis for perception by advancing an “isomorphic” theory of brain activity, stating that perceptual organization takes place in the brain, and formulated a number of Gestalt principles to explain the dynamics of perceptual patterning, such as closure and grouping of similar items. He believed these principles demonstrated that immediate experience is basically an orderly affair—that is, we do not have to create order, since it is already there.Wertheimer’s point of view was developed and disseminated by Kohler and Koffka. Kohler is best known for his study of insight, and his comparative studies of the thinking processes of men and apes carried out between 1917 and 1922. Koffka introduced the theory to America in 1922, and applied the Gestalt principles on thinking in the field of education. These principles were most fully presented in a posthumously published book of Wertheimer’s, Productive Thinking (1945). In it he showed that the educational systems of the time closely followed the association theory, and as a result the child was taught by rote memory rather than by gaining insight into principles. He demonstrated, for example, that children who were taught to find the area of a parallelogram by rote could not solve the same problem if the figure was rotated 90 degrees. On the other hand, if the teacher helped them understand the reasons behind the solution, and if they were given practice in seeing problems as a whole, their thinking became more flexible and productive. Children taught in this new way developed an ability to “re-center their thinking”—that is, to see the problem in a fresh light and discover new relationships that usually suggested a solution.