ABSTRACT
This chapter examines the measurement of physiological and behavioral events that were regarded for centuries as ineffable and, hence, resistant to quantitative studies. The mechanistic perspective inspired new quantitative studies in physiology and behavior, a philosophy that begins in the modern period with Thomas Hobbes. Hobbes's reduction of philosophy to the study of bodies in motion marks him as an important figure in the history of psychology. A mechanical model holds promise for psychologists to discover material and efficient causes. Popular mechanical inventions included toys, clocks, and windmills that dazzled the public with their intricate movements. The concept of the reflex was a central building block in the mechanistic viewpoint because it sharpened the distinction between voluntary and involuntary action. Rene Descartes believed that many human movements and all animal movements are mechanical or nonreflective. He applied the mechanical-hydraulic explanation to all animal movement and to involuntary human movement.
