Those authors who have attempted to trace the evolution of Gestalt theory, or those who have had occasion to examine its origins, are unanimous in indicating an experimental study by Max Wertheimer (1880–1943) as marking its beginnings.¹ The subject-matter and approach of Wertheimer's study had none of the features typical of a manifesto for a new line of thought, such as those displayed, for example, by the article "Psychology as the Behaviourists View It' published by John B. Watson (1878–1958) just one year later than Wertheimer's and which inaugurated the behaviourist movement.