Read The Story of Psychology Online
Authors: Morton Hunt
He imagined that the flow of animal spirits also powers digestion, the circulation of the blood, and respiration, and some psychological functions, like sensory impressions, the appetites and passions, and even memory. The latter, though seemingly a function of mind, he explained in mechanical terms. Much as holes in a linen cloth pierced by needles remain when the needles are removed, so repeated experiences make certain pores in the brain remain more open than others to the flow of
the spirits.
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Descartes thus dispensed with Aquinas’s theory (derived from Aristotle) that the soul has “vegetative” and “sentient” as well as rational functions. In Descartes’ system it was purely rational; the other functions belong to the body.
Erroneous as his mechanical-hydraulic theory is in its details, it is impressively close to right in one major respect: it attributes the control of the muscles to impulses traveling from the brain through efferent nerves. Even more impressive is another of his guesses. He asked himself what initiates the flow of animal spirits to the muscles and again used the analogy of the royal automata, which were activated by water turned on when a visitor stepped on hidden pedals. In living creatures, he suggested, sensory stimuli play the same part by creating pressure on the sense organs; this pressure, transmitted by the nerves to the brain, opens particular valves, thereby causing bodily action of one kind or another. Descartes was thus the first to describe what would later be called the
reflex
, in which a specific external stimulus causes the organism to respond in a specific way.
But the mechanical-hydraulic theory did not explain consciousness, reasoning, or will. Those higher mental activities, Descartes believed, must be functions of the soul (or mind). Whence does this thinking soul get its information and ideas? He says that when it coexists with the body during life, it acquires some ideas via the body’s perceptions, passions, and memory, and it manufactures others—imaginary objects, dreams, and the like—out of remembered sensory impressions. But its most important ideas cannot come from such sources, for while he is aware of his own thinking and therefore knows that his soul exists, he never experiences his soul in a sensory fashion. The idea of the soul must be part of the soul itself. Similarly, such abstract concepts as “perfection,” “substance,” “quality,” “unity,” “infinity,” and the geometrical axioms seemed to him to be independent of sensory experience and so had to originate in the soul itself; they are innate.
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He reasonably added that such innate ideas do not exist full-blown at birth; rather, the soul has a tendency or propensity to develop them in response to experience. They are “primary germs of truth implanted by nature”; sensory impressions cause us to discover them within ourselves. For example, a child cannot understand the general truth “When equals are taken from equals, the remainders are equals,” unless you show him examples.
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His dualistic conception of body and soul presented one exceedingly difficult problem. When body and soul are locked together during life,
they interact. The body’s experiences engender passions in the soul, and the soul’s thoughts and will direct the flow of animal spirits, producing voluntary movement—but where and how does the interaction take place? How can the incorporeal soul, possessing no solidity and occupying no space, connect with the corporeal body and receive its perceptions and experiences or exert any influence over it?
Earlier dualistic philosophers had ignored this problem; the physiologically aware Descartes could not. From his and others’ anatomical studies, he knew that the brain has two identical hemispheres but that deep within it is a tiny gland (the pineal body); because this is single, like the soul itself, and because of its position in the brain, it seemed to him the obvious junction of soul and body. He conjectured that, due to its position in the brain, “its slightest motions can greatly affect the flow of the spirits, and conversely the slightest changes in the flow of the spirits greatly affect the motions of the gland.”
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While he never explained how the corporeal pineal gland and the incorporeal soul could make contact, he felt sure that they did and that it was through the gland that the soul affected the body, and the body the soul:
The whole action of the mind [i.e., soul] consists in this, that by the simple fact of its willing anything it causes the little gland, to which it is closely joined, to produce the result appropriate to the volition
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… [Conversely,] the movements [of the gland] which are excited in the brain by the nerves affect in diverse ways the soul or mind, which is intimately connected with the brain, according to the diversity of the motions themselves.
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The body thus engenders in the soul such passions as love, hatred, fear, and desire. The soul consciously considers each passion and freely wills to act in response to it—or, if it deems the passion undesirable, to ignore it. Why, then, do we ever do wrong? Not because the soul chooses to or is in conflict with itself, said Descartes, but because very intense passions may produce “commotions” of the animal spirits that override the soul’s control of the pineal gland, eliciting responses contrary to the soul’s judgment and will.
But one of Descartes’ major goals in setting forth his psychology was to show how to control the passions through reason and will. He offered much sensible advice, such as when powerful passion is aroused, one should deliberately divert one’s attention elsewhere until the agitation calms down, and only then make a judgment as to what to do. Most of
what he said about controlling the passions is on this level; it is the least interesting part of his psychology.
He classified the passions, but without giving any illuminating theory as to their origins. There are six primary ones—wonder, love, hate, desire, joy, and sadness—all the rest being varieties or combinations of these. Unlike his dramatic description of his search for a first philosophic principle, his discussion of the passions was definitional and dry as dust. A single example will serve:
Love is an emotion of the soul, caused by the motion of the spirits, which incites it to unite itself voluntarily to those objects which appear to it to be agreeable. And hatred is an emotion, caused by the spirits, which incites the mind to will to be separated from objects which present themselves to it as harmful.
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Although Descartes’ explanation of the interaction between body and soul is quite wrong—the pineal gland, which produces melatonin and influences vision and sleep, has no influence on either efferent or afferent nervous impulses—the mechanical details are unimportant. What is important is his theory that body and mind are separate entities, composed of different substances, which interact in a living person, sometimes harmoniously, sometimes competitively, and that this competition is the most crucial aspect of human existence. The theory greatly influenced the human search for self-understanding, but not for the better. Raymond Fancher, a historian of psychology, sums up the weakness and the power of Descartes’ dualistic theory:
On the one hand, he taught that a person was a machine, capable of being studied by the methods of natural science. On the other hand, he taught that the most valuable and unique human attribute, the soul, was beyond the reach of scientific method and could be understood only by rational reflection. And then finally the interaction between body and soul was said to be deducible through a combination of anatomical inference, psychological introspection, and a peculiarly empty logical analysis…
Despite the logical difficulties with parts of Descartes’ position, most people—at least in the West—continue to think of their minds and their bodies as separate but somehow interacting aspects of themselves. This is a tribute to the power of Descartes’ theory. Whatever its faults, his interactive dualism captured the Western imagination to
such an extent that it became accepted almost as a matter of course. Few theories, in any discipline, can claim equal success.
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Over the next century a number of Descartes’ followers, usually referred to as the Cartesians, tried to modify his psychology so as to explain how the soul, an immaterial substance not occupying any space, could act upon the material, three-dimensional pineal gland, or vice versa.
Their chief approach was to suggest that actually there is no causal contact between body and mind; God sees to it that whatever happens in one sphere is accompanied by the appropriate happening in the other. This theory would seem to keep Him continually busy, running two worlds for each living person, but one ingenious Cartesian, Arnold Geulincx (1625–1669), suggested that body and mind are like two clocks that God winds up and sets running in perfect harmony with each other, after which He need do nothing more. Mental events only seem to produce physical responses, physical experiences to produce mental responses, but in fact each train of events merely occurs in perfect synchrony with the other.
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Whether “parallelism,” as this theory is called, is best thought of as metaphysics, theology, or wonderful nonsense, it is clearly outside the realm of psychology; let us pass it by.
But we must not pass by the work of one other major philosopher who, by purely rationalist means, arrived at very different answers from Descartes to the questions of free will, causality, and the body-mind problem. He was Benedict Spinoza (1632–1677), the gentle, quiet Dutch Sephardic Jew whom Bertrand Russell calls “the noblest and the most lovable of the great philosophers” and whose
Ethics Demonstrated in Geometrical Order
(1677) is the most austerely rationalist, but one of the most exalted, of philosophic works.
His influence on psychology, however, is problematic; some scholars have thought it major, others minor. In part, their opinions vary because the
Ethics
, in which Spinoza discusses psychological matters, is hard to understand, being formidably geometric in presentation (axioms, propositions, demonstrations, and QEDs) and filled with metaphysical terminology. But in larger part appraisals of his contribution vary
because some of his ideas about the universe and about psychology seem so modern, others so archaic.
His most modern idea is his definition of God: Spinoza makes Him identical with the universe and all the mind and matter in it, subject to its laws, and hence unable to intervene in the order of events. In consequence, Spinoza was harshly condemned by some as an atheist but praised by others for seeing God in all things. The philosopher Bishop George Berkeley thought him “wicked” and “the great leader of our modern infidels,” but the German Romantic poet and dramatist Novalis called him
der gottbetrunkene Mensch—
the God-intoxicated man. It is possible to hold either of two equally diverse views about his psychology.
Spinoza was educated in Jewish learning at the synagogue in Amsterdam, where his family lived. But being of a scholarly and inquiring mind, he mastered Latin in his early twenties, took up the study of philosophy, and absented himself from services at the synagogue. The leaders of the Jewish community feared he would become a Christian and offered him a pension of a thousand florins a year if he would conceal his disbelief and appear now and then in the synagogue. An apocryphal story says that when he refused, they tried to have him assassinated, but the attempt failed. It is historical fact, however, that they excommunicated him and pronounced him cursed with the curses that Joshua had laid upon Jericho and those which Elisha had laid upon a band of children who had mocked him and who, in consequence, were torn to pieces by she-bears. The excommunication and curses, the only dramatic note in Spinoza’s biography, had no effect on him; he led a quiet and uneventful life in Amsterdam and later at The Hague, earning a meager income as a lens grinder and tutor, living most of his adult years in a single room, going out but rarely, and dying of tuberculosis at forty-five.
Spinoza was greatly impressed by Descartes’ philosophy and, like him, used pure reasoning to deduce the nature of the world, God, and the mind. But he found Descartes’ theory about the pineal gland totally unconvincing and lacking in proof,
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and therefore saw no merit to his explanation of how body and mind interact. Unlike Descartes, who believed in free will, Spinoza saw all mental events, like all events in the physical world, as having causes, which in turn have preceding causes; he was, in short, a complete determinist, as he made clear in the early pages of the
Ethics:
*
axiom 3: From a given determinate cause an effect necessarily follows; and, on the other hand, if no determinate cause can be given, it is impossible that an effect can follow.
PROP
. 29:
In nature there is nothing contingent, but all things are determined from the necessity of the divine nature to exist and act in a certain manner.
Demonst.:
Whatever is, is in God; but God cannot be called a contingent thing, for He exists necessarily and not contingently. Moreover, the modes of the divine nature have followed from it necessarily and not contingently, whether it be considered absolutely or as determined to action in a certain manner.
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To decode this difficult language, for “God” substitute “the universe,” for “modes of the divine nature” read “mental and physical events,” and replace “contingent” with “not caused by something else.” It then becomes clear that Spinoza’s world, including human mental activity, is wholly subject to natural laws and capable of being understood.
He thus anticipates the fundamental premise of scientific psychology. He also says that the most basic of human motives is self-preservation;
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again, this anticipates modern psychological theory. Yet his ideas affected the development of psychology only indirectly; his impact on modern thought, say Drs. Franz Alexander and Sheldon Selesnick in their
History of Psychiatry
, “was so pervasive that many of his basic concepts became a part of the general ideological climate” and in that way influenced Freud and others without their knowing it.
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