ArgumentAfter having measured the velocity of the nervous impulse in the 1850s, Helmholtz began doing research on the temporal dimensions of visual perception. Experiments dealing with the velocity of propagation in nerves were carried out occasionally for some fifteen years until their final publication in 1871. Although the temporal dimension of perception seems to have interested Helmholtz less than problems of geometry and space, his experiments on the time of perception were technically rather subtle and seminal, especially compared with experiments (...) performed by his contemporaries, such as Sigmund Exner, William James, Rudolf Hermann Lotze, Ernst Mach, Wilhelm Volkmann, and Wilhelm Wundt. Helmholtz’s conception of the temporal aspects of perception reflects the continuity that holds between psychophysiological research and the Kantian philosophical background. (shrink)

Gustav Theodor Fechner was one of the outstanding German scientists and thinkers. He is well known as eminent founder of a new science Psychophysics —the quantitative study of the relations between physical stimuli and sensations. But it seems that first idea and first solutions of this new science are not the result of hard experimental work but rather of metaphysical speculations. So we found for the first time the important Fundamentalformel in thephilosophical book Zend-Avesta , written by Fechner already in (...) 1851. Therefore this formula may not be the result of hislater experimental efforts, put down in writing in the important Elemente der Psychophysik (1860). In the present paper it was intended to retrace the so called indefinite train of thoughts (Fechner) that leaded him to his strictly mathematical formula. (shrink)

In the early nineteenth century, a group of German biologists led by Johann Friedrich Blumenbach and Karl Friedrich Kielmeyer initiated a search for laws of biological organization that would explain the phenomena of form and function and establish foundations for a unified theory of life. The tradition spawned by these efforts found its most important spokesman in Karl Ernst von Baer. Timothy Lenoir chronicles the hitherto unexplored achievements of the practitioners of this research tradition as they aimed to place functional (...) morphology at the heart of a new science, which they called "biology." Strongly influenced by Immanuel Kant, the biologists’ approach combined a sophisticated teleology with mechanistic theories and sparked bitter controversies with the rival programs, mechanistic reductionism and Darwinism. Although temporarily eclipsed by these two approaches, the morphological tradition, Lenoir argues, was not vanquished in the field of scientific debate. It contributed to pathbreaking research in areas such as comparative anatomy, embryology, paleontology, and biogeography. Preface Introduction 1. Vital Materialism 2. The Concrete Formulation of the Program: From Vital Materialism to Developmental Morphology 3. Teleomechanism and the Cell Theory 4. The Functional Morphologists 5. Worlds in Collision 6. Teleomechanism and Darwin’s Theory Epilogue Notes Name Index Index. (shrink)

David Cahan has assembled an outstanding group of European and North American historians of science and philosophy for this intellectual biography of Helmholtz, ...