Graziano & Raulin
Research Methods (9th edition)
Rene Descartes (1596-1650) was a French mathematician and philosopher, who made major contributions to the emergence of modern science in general, and the later development of psychology.
It was Descartes’ belief that a universal theory of mechanics would one day be developed, and that scientific understanding of the universe would rest upon mathematical principles. He asserted that true science, as defined in his Discourse on the Method of Rightly Conducting the Reason, and Seeking for Truth in the Sciences (1637), would be based on those principles of mechanics and mathematics. This mechanical and mathematical philosophy and view of science would become a major foundation for the physics and astronomy of the 18th Century, with particular influence on Newton. It would also become a rationale for much of the later biological research and for two basic ideas in psychology, the reflex arc and mind-body interaction (discussed below). The reflex arc, as we will see, was central in the work of Pavlov, Thorndike, Watson, and other behaviorists of the 20th Century. Mind-body interaction became an underlying principle in virtually all of psychology.
Of particular importance for psychology was Descartes's conception of mind-body interaction. He believed that the single function of mind was thought (reason)--a very Socratic notion. All else, perception, feeling, emotion, movement, etc., were functions of the body. This mind-body dualism was well-accepted doctrine long before Descartes. However, if as the philosophers had long believed, mind and body are separate entities with different qualities and functions, then what is the nature of the relationship between them? This was the centuries-old mind-body problem. The accepted answer had long been the Socratic view that mind controls body, and never the other way around. This idea constituted a philosophical dualism, with mind ascendant over body.
Descartes, however, had a new interpretation. He agreed that the two domains--mind and body--were separate entities, but he argued that they interacted with one another. Each domain could influence the other. Descartes’ concept of mind-body interaction--that mental events can influence the body and the body can influence mental events--was to replace dualism and become an influential concept in the development of psychology over two hundred years later. We will see this particularly in the American Functionalist movement in psychology in the 20th Century.
In keeping with the interaction model, Descartes believed that some physical functions occurred without the influence of the mind. For example, he conceived of an early version of what is now called reflex action, in which a stimulus can cause a mechanical reaction within the body without any conscious or mental involvement. His example was the automatic pulling of one’s hand away from a hot coal. This concept can be seen in later physiology and in the psychological models of Pavlov, Thorndike, Watson, Hull, and Skinner.
Descartes’s ideas helped to direct future scientists to the objective study of the physical body on the one hand, and the “mind” on the other. We see this development beginning in the mid-nineteenth century, when objective study of the physical body--its structures and functions--was well under way. Objective study of the mind soon followed, as early psychologists, such as Wundt and Titchener, applied scientific methods to study human consciousness. That is, manipulation and observation of the overt responses of subjects (functions of the body) could reveal the subjects’ consciousness (the internal functioning of the mind). Descartes’s concept of mind-body interaction was one of the major ideas that paved the way for that study of consciousness.
In Descartes’s model, humans are both mechanical and reasoning beings, but animals are purely mechanical automatons. He argued that animals possessed none of the higher functions of humans – intelligence, reasoning, anticipation, emotions, and the perception of pain or joy. This was unfortunate, because it gave a clear philosophical support for the generally held notion that animals are incapable of feeling pain or such emotions as fear and terror. It also provided a rationale for the widespread development of vivisection, in which 17th through 19th Century scientists carried out painful experiments on live animals, all the time reassuring themselves that the screams and yelps were not from pain, but rather were mere mechanical reactions of totally unfeeling creatures.
Descartes’s contributions to later psychology include the concepts of the physical body as a complex machine, reflex action, and the interaction of mind and body. Other philosophers, impressed by Descartes’s conceptions, believed that a mathematical approach is applicable even to the human mind and emotions (e.g., Spinoza, 1632-1677), a development that actually occurred in the 19th Century.