Werner¿s pivotal role between European and American intellectual traditions is illuminated through the use of rich memories of his former students, unique documents from Werner¿s personal library at Clark, and analyses of links with other European traditions in philosophy and biological sciences. The European period (prior to 1933) in Werner¿s academic life is found to be definitive for Werner¿s contributions to science. The ideas developed in his early career continued in the form of a productive empirical research program in the 1950s at Clark. An analysis of the social-intellectual climate of the development of psychology in America in the 1950s is a special feature of this book that will further enhance an understanding of Werner¿s unique contribution This book will be of interest to developmental psychologists, sociologists and historians of science, philosophers, practitioners working in special education and neuropsychology, and for general readers interested in the history of ideas and life courses of scientists.