Story of Psychology - Morton Hunt [67]
—According to Descartes’s animal-spirits theory, impulses could flow in the nerve in either direction. According to the electrical model of nervous activity, current flowed in only one direction. Espousing the latter concept, between 1811 and 1822 Charles Bell, an English anatomist, and François Magendie, a French physiologist, working independently, cut different nerves in animals to see what functions were affected. Both men were able to show that the nervous system consists of sensory nerves in which the current is afferent, flowing toward the spinal cord and brain, and of motor nerves in which it is efferent, flowing from the brain and spinal cord toward the muscles and organs.
These and a number of other discoveries, combined with what was already known of the physics of light and color, produced a nineteenth-century explosion of research in the physiology of the sense organs and perception. This new psychology was a radically different approach from the theistic fantasies of Berkeley and the skepticism of Hume to the question of how the mind perceives the world around it. And although at first it could deal only with lower-level psychological processes, most of the new psychologists hoped that eventually higher-level ones would be explicable in similar terms. Emil Du Bois-Reymond, a German physiologist, wrote to a friend in 1842 that he and a colleague had taken a solemn oath to demonstrate the truth of the following creed:
No forces other than the common physical-chemical ones are active within the organism. In those cases which cannot at this time be explained by these forces, one must either find the specific ways or form of their action by means of the physical-mathematical method, or assume new forces, equal in dignity to the chemical-physical forces inherent in matter and reducible to the force of attraction and repulsion.14
Although the “new psychology,” as it became known, appeared in a number of countries, it made its strongest showing in Germany, in whose universities, according to the eminent English historian of psychology Leslie Spencer Hearnshaw, “scientific psychology was born.”15
Nor, he says, was this any accident. Until 1870, Germany comprised a multitude of kingdoms, duchies, and self-governing cities, and had created many more universities than any other European country. Moreover, after certain educational and social reforms of the early nineteenth century, German universities supplied their scientists and scholars with well-equipped laboratories for research in physics, chemistry, physiology, and other sciences.
In that atmosphere, even philosophers and psychologists in the Kantian tradition rejected Kant’s assertion that psychology could never be an experimental science. Others came to believe that even the invisible higher-level mental functions, observable only through volunteers’ reactions to stimuli, could be experimentally and validly investigated.
But first we will look at the mechanists—or, rather, since there were many of them, at a few whose work was both particularly important and typical of the movement.
Specific Nerve Energy: Müller
Johannes Müller (1801–1858) began in the philosophic tradition, broke away from it to become the first great modern physiologist, then drifted back to philosophy in an effort to answer questions about the soul that lay beyond his physiology.16 But the time of philosophic psychology was over; his physiological work had considerable influence on psychology, his philosophic work none.
Müller, born in Coblenz of middle-class parents, was extremely gifted, energetic, and driven by a compulsion to excel. He was also endowed with Byronic looks—tousled hair, a sensitive mouth, and piercing blue eyes. Having earned his medical degree in Berlin when he