Extract From: Edna Heidbreder (Chapter 2) "Prescientific Psychology" (pp. 18-70). In Heidbreder, E. (1933). Seven Psychologies. New York: D. Appleton-Century Co.

PRESCIENTIFIC PSYCHOLOGY

[p. 18]....The young science of psychology is continually discovering that its favorite problems have histories; that its very terms have implications which connect them with preexisting points of view, and that its conclusions are often determined by custom and association. Its path is anything but a straight line; its is always being pulled this way and that by the attraction of some body of knowledge or opinion of which it may hardly be aware....

.... [p. 21]....The early Greeks, with the utmost directness, wanted to know what the world was made of. Their answer was found when they had analyzed the complexity of the world as they saw it into some one element -water, air, atoms- or into a system of elements. The task they set themselves was that of reducing the complex to the simple, and their assumption was that the complex and the manifold form the world of appearance, in destination to the underlying reality, which is simple. This task and this assumption have never ceased to appeal to the human intellect. They imply that the universe, or that part of it which one is investigating, can be understood by discovering the units of which it is made. Physics has found such units in atoms; biology, in cells; and psychology, depending upon the point of view adopted, in simple ideas, sensations, or bits of behavior involving elementary stimulus-response connections. But whatever the unit, the principle of construction [p. 22] is always the same; it involves in some form, coarse or subtle, the conception of the universe as a composition of parts, a mixture of simples. To a manipulative animal like man, this is a long step toward making the world intelligible. He knows what it is made of; he can see how the parts are put together; if he had the parts, he could put them together himself. It is true that the engaging simplicity which characterizes this view at first glance grows less apparent on examination; difficulties emerge that are not immediately evident. But so long as one does not pry too curiously below the level of common sense, the method is satisfying and useful. It has repeatedly proved its effectiveness by achievement; and it is beyond question one of the readiest and most dominant responses of human beings faced with complex situations. It is a method that appears over and over, in one form after another, in the attempt to deal with psychological material.

Democritus, the last of the ancient cosmologists, represents this way of looking at things in the most finished form it assumed in Greek thought. The nimble-witted Greeks had not permitted the cosmological speculations to go their ways without criticism. Early in the sixth century B.C., Thales, the first Greek philosopher known to history, had found his unit in a concrete substance, water. But this position was only a starting-point, and the story of the development that followed is one of speculation submitted to criticism, and of fresh speculation submitted to fresh criticism. Out of this development, about a century and a half later, came the formulation of Democritus, free from the more obvious difficulties of the earliest speculations, clear, intelligible, complete, and abstract. According to Democritus the universe is made of atoms. The atoms are small particles of matter in motion; they move in different ways; they are different in size and form, but they move according to necessity or [p. 23] law. Man, like the rest of the world, is composed of atoms, of soul atoms and body atoms, which are alike material but which differ from each other in that the soul atoms are finer and more active. Man's thoughts and deeds, all the events of his life, are determined as rigidly as the courses of the stars. In Democritus, atomism is definitely allied with materialism and determinism, which in his thought appear in their clearest and least ambiguous forms and with their logical implications for human actions and destinies fully recognized.

A second development rose as a criticism of the first. Long before the time of Democritus, there were philosophers who saw difficulties in the apparently simple device of reducing the world to elements. One of these was Heraclitus, who expressed his dissatisfaction somewhat paradoxically in the thesis that the element which constitutes all nature is fire. But though Heraclitus apparently meant fire in the literal sense -as literally as Thales meant water- he saw as its significant characteristic, impermanence or change. At the core of the universe he found no lasting substance, nothing solid, nothing enduring, nothing that could serve as a stable element. The very mountains, he pointed out, are not the same from age to age, nor from day to day; one cannot step into the same stream twice. Only change is real: "Everything flows" is his central teaching. Essentially this doctrine is a critique of common sense. "Things" are not real; they are forever vanishing, passing into their opposites. The senses may reveal what seem to be substantial objects, but thought, transcending appearance, perceives reality, which is change. Whereas common sense sees things, Heraclitus saw processes, and in doing so employed a conception similar to that used in the physics of today, which is depriving matter of its stability and solidity. The relevance to psychology of this mode of thinking is immediately apparent. A psychologist cannot have even a slight firsthand knowledge of [p. 24] his subject-matter without realizing that he is not dealing with bits or particles of anything stable and substantial, but with transient processes. Even in those systems of psychology which reduce their material to elements, the elements, whether bits of consciousness or bits of behavior, are defined as processes. It is true that, having been defined as processes, they are often, in actual practice, treated as fixed units, for the habit of thinking in terms of fixed units is tenacious. But when attention is turned upon psychological material directly, the character of change presents itself as an inescapable fact. Psychology is continually emphasizing the point that it is dealing with processes and events.

A third development was that started by Anaxagoras. Like Heraclitus, Anaxagoras in fact postulated an indefinite number of qualitatively different elements. His problem rose from the consideration that, granted one knew the elements, one would still be unable to account for the world as we see it. The arrangement of the elements he found as important as their existence. The order of the world must be explained as well as its constituents, and the ordering principle he found in nous, something corresponding to human intelligence or reason, but not yet contrasted with matter. This doctrine is significant to psychology partly because it singles out a psychological process for special attention and partly because, in emphasizing the question of arrangement, of order, of pattern, it brought up a problem that repeatedly recurs in psychology. It is the latter point -the protest against a reduction to elements as a complete explanation- that gives the philosophy of Anaxagoras its chief significance for modern psychology. It is a view [p. 25] closely related to the persistent protests against the various forms of sensationalism, and it is not unlike the revolt that the Gestalt movement, one of the newest of the psychologies, is directing against psychological atomism today.

A fourth movement represents a very different way of accounting for the universe. Its origin is associated with the name of Pythagoras and its doctrine is that reality can be understood through number. In the Pythagorean school, this doctrine took on the character of a cult. It was surrounded by mystical and fantastic and sometimes trivial teachings, and was accompanied by such specific and apparently meaningless rules of conduct as the prohibition against eating beans. But the attempt to know the world in quantitative terms is itself of the highest importance, and it is interesting that such an attempt made its appearance as early as it did. Science, striving for exact knowledge, has always eagerly joined hands with quantitative thought and, as will appear later, the successful application of quantitative methods to psychological material was historically one of the decisive factors in making psychology a science.

But gradually, in the course of these inquiries into the nature of the universe, in the midst of all these theories, each claiming to be right and each supporting its claim with a degree of plausibility, there arose a question of another sort -the question "How can we know?" Primarily this was not a psychological question; it was not "How do we know?" but "How can we know?" and it was occasioned less by curiosity about the process of knowledge than by concern for the validity of knowledge. Still, this concern for the validity of knowledge led to inquiries into the processes of knowledge. Very early, philosophers had distinguished between knowledge gained by the senses and knowledge achieved by reason. They had noted, too, that knowledge is [p. 26] relative, that our knowledge is human knowledge, gained from a human point of view, colored by human ways of knowing. The next step was to inquire whether any human mode of conceiving the world can have objective validity, whether inquiry into the ultimate nature of reality is not, after all, quite futile.

The Sophists, starting from this point of view, gave a radically new direction to Greek thought. They turned definitely from cosmology to human affairs, and thus became interested in matters that may be termed, in the broad sense, psychological. Furthermore their approach was practical. It was inevitable that the very wealth of speculation about the universe, the spectacle of successive explanations of all but equal plausibility, should impress some minds chiefly with the uselessness of such speculation. The Sophists, at any rate, refused to occupy themselves with attempts to understand the fundamental nature of reality. They turned instead to their business, which was the teaching of philosophy as a way of life, and of rhetoric and dialectic as practical skills. Deliberately superficial and adroitly practical, they undertook, for pay, to train young men in the arts of persuasion -arts that were distinctly useful in the Greek city-state where men rose to power by convincing their equals and swaying the populace. There were, of course, Sophists and Sophists, representing a range of intellectual integrity from delight in the unhampered exercise of critical intelligence to the wish to "make the worst appear the better reason." But whatever their views on the usefulness or uselessness of dialectic, the process itself interested them. In it they found something with which to busy themselves, something that could be exercised and cultivated and controlled, something, furthermore, which -whatever the ultimate nature of reality might be- was important in the world of affairs. With an attitude curiously similar to that of modern applied [p. 27] psychology, they turned to specific performances and concrete situations, far more interested in manipulating the immediate and the actual than in delving into the fundamental and profound. It would be a mistake, of course, to ascribe wholesale to modern workers in applied psychology the views associated with the Greek Sophists, but whatever the theoretical starting-point of their activities, something in their temper is similar. The great virtue of applied psychology is its healthy association with the actual and the immediate, its practice of keeping close to, or at least within sight of, materials that human beings can manipulate and control.

An indirect consequence of the teachings of the Sophists was the philosophy of Socrates, one of the most picturesque figures in the brilliant society of the Athens of the fifth century B.C. Socrates was ugly, charming, eccentric, convivial, and high-minded, a man who made it the serious business of his life to inveigle young men into philosophical conversations and to lead them, by artful questioning, to see that their ideas about the most fundamental and even the most commonplace affairs of life were confused and self-contradictory. His aim was to confront his listeners with the necessity of defining their terms exactly, and to urge them to discover what reason revealed as true. His success in making his hearers question apparently obvious truths was so great that as an old man he was tried an condemned to death on the charge of undermining the religion of the state and corrupting its youth.

Like the Sophists, Socrates believed that inquiry into the nature of the cosmos is futile, but unlike them, he believed that one kind of knowledge is obtainable -knowledge of the self. Furthermore, he believed that it is this kind of knowledge that men really need, knowledge that will reveal their duty and enable them to lead virtuous lives. Socrates believed [p. 28] that virtue is the outcome of knowledge and that evil is fundamentally ignorance -an early instance of the belief repeatedly encountered in psychology that the intellectual or rational principle is dominant in man. Socrates believed, too, that truth is implicit in the human intellect; that it needs only to be drawn out and clarified. To demonstrate this point, he led an untaught slave, aided only by skillful questions, to discover for himself that the square on the hypotenuse of a right-angle triangle is equal to the sum of the squares on the other two sides.

And yet, Socrates was more interested in the total nature of man than in any of his particular abilities. Essentially, his interest in human being was ethical, and this fact is responsible for one of the distinctive features of his psychological approach. He considers men not as isolated units but always in relation to their fellows and to the state. In a sense, this view is like that of the modern behaviorists, who believe in studying the whole organism in its relations to its environment. It is true that behaviorism in its early days tended to be interested largely in the physical environment, whereas Socrates was interested chiefly in the social environment; but of late behaviorism has been placing more and more emphasis on the social influences in human life and is coming into closer and closer relations with ethical problems.

Socrates' most distinguished pupil was Plato, who formulated for the first time the clear-cut distinction between mind and matter that has figured prominently in psychology down to the present time. Both by birth and by temperament Plato was an aristocrat, a man who had little interest in the common affairs of everyday existence, and who gave himself over as completely as possible to the life of reason. For Plato believed that in the life of the intellect man was expressing his highest possibilities. In his life of contemplation, he was deeply impressed by the difference between [p. 29] ideas, which are revealed by reason, and things, which are revealed by the senses; and placing ideas in a world by themselves, he regarded them as far more real than the world known to the senses. Ideas, Plato noted, have a perfection that is never present in concrete things. The idea of beauty, for instance, is permanent, flawless, immutable, absolute; whereas beautiful things, which are beautiful only in relation to something else, are imperfect, changing, and impermanent. To Plato it seemed evident that the permanent, the perfect, the changeless, and the absolute must be more real than the perishable, changeful, imperfect objects which, however much of beauty they may contain, can only approximate pure beauty as such. He therefore posited a world of ideas, of which the "real" world -the world revealed by the senses- is only an imperfect copy. Matter is the substance in which ideas express themselves, but its very nature makes their perfect expression impossible, for it imposes its own limitations upon them and robs them of their purity. Thus Plato not only established a distinction between mind and matter, but associated those terms with opposed sets of values. Mind was identified with the good and the beautiful. Matter was the enemy, the baser part of man and of the universe, something to be struggled against and subdued. This distinction, along with the values with which Plato invested the terms, has persisted to the present time. There is still a tendency in everyday thought to regard mind as lofty and matter as ignoble. In some quarters, however, there has been a curious inversion. The triumphs of modern science have been triumphs of physical science; the scientific method and point of view have been associated with the study of physical nature; and to those who have acquired a set of values different from Plato's -who contrast the scientific and the unscientific, not the noble and the base- mind and matter have changed places in the scale of values. It is matter [p. 30] that lends itself to the ways of science; it is mind that is disturbing and untractable [intractable?]. By easy stages mind is identified first with the highest good, then with the ineffable and the unattainable, and finally with the mystical and the unscientific; and in consequence the Platonic distinction, largely through the values that cling to its terms, even today determines attitudes in science.

When Plato considered men, he naturally thought of them from the standpoint of his own interest in the life of the intellect. Ranking men's powers from highest to lowest, he named first reason, which resides in the head; then courage which resides in the chest; and last sense and appetition, which reside in the abdomen. Plato looked upon these powers as parts of the soul and thus employed a mode of thought similar to that which was later to be called faculty psychology. Plato also recognized individual differences among men. In the ideal state, the Republic, men were to be chosen for their several duties with reference to their abilities. Those endowed with superior reason were to be rulers; those endowed with courage, warriors; the rest of mankind were to be artisans, tradesmen, laborers, and slaves -necessary to the state, but lower in rank than warriors and statesmen, as the appetites and senses are lower than courage and reason. This part of Plato's thought, however, has had relatively little effect on modern psychology. The chief source of his influence is his distinction between mind and matter and his identification of mind with the unearthly -a distinction that still lives in the belief held by some psychologists that the mental can never be an object of scientific knowledge.

But the Greeks themselves did not despair of understanding the mind. Aristotle, Plato's pupil and successor, and to some extent his rival, in attempting to make a comprehensive survey of being, addressed himself to the things of the mind in much the same manner as to anything else in the [p. 31] natural order. However, his distinction between mind and matter was not the same as Plato's. He thought rather in terms of matter and form. In outlook and temperament, Aristotle was very different from Plato. He was interested in the concrete and the actual as Plato was not, and turning his attention in that direction, he found no sharp distinction between matter and mind or, as he put it, between matter and form. It seemed to him that neither existed apart from the other. Form exists in the concrete object, he said, not as a separate entity. Matter is potential form; the actual object is form realized in matter, it is the union of form and matter. Marble is matter to the statue; the statue is form realized in marble. Furthermore, the distinction between form and matter is not absolute; the marble that is matter to the statue is form to lower organizations of matter. Thus concrete reality arranges itself in a series in which it is impossible to indicate a point and say that on this side there is matter, on the other, form. This concept of continuity, too, though in a context very different from Aristotle's, is one that is often encountered in the psychology of today. Like Aristotle, modern psychologists, when confronted with concrete data, find it impossible to fix hard and fast boundaries; they cannot point to a dividing line between conscious and unconscious processes, between intelligence and feeblemindedness, between anger and fear, between sanity and insanity, between instinct and reason, between childhood and maturity, between psychology and physiology. They deal far less in absolute distinctions than in series in which there are continuous gradations between extremes.

Closely related to the concept of matter and form is the practice of explaining phenomena in terms of final causes. Aristotle made one exception to the rule that form never exists alone. The final form, the Supreme Being, can be matter to nothing beyond. It is therefore pure form; and [p. 32] since all matter strives to realize itself in form, this final form is the goal toward which all nature moves. Therefore all nature, including human nature, is explained teleologically as tending toward an end or goal. But since science deals with proximate causes, with the events immediately antecedent to a given effect, it has not been hospitable to the notion of teleology. Another implication of Aristotle's general scheme, however, has very definitely appeared in modern psychology. In the world of nature, Aristotle finds matter and form are always related. If the whole body were an eye, the soul would be seeing. The body exists for the sake of the soul, but the soul exists only in and through the body. The activities of the soul, in other words, are activities of bodily organs. It is as impossible to desire and strive without the appropriate physical structures as to see without eyes. He regards particular psychological processes as activities or functions of physical structures, existing in a world where such activity is definitely related to a particular physical constitution.

But in the soul, Aristotle distinguished between a mortal and an immortal part. Activities that are functions of bodily structures perish with the body, but there is in man an active intellect that is not a function of the body. It is this active intellect which Aristotle declares to be simple, immaterial, and immortal; and it was this part of Aristotle's teaching, his recognition of the active intellect, which claimed the greatest interest of the schoolmen of the Middle Ages.

In addition to his treatment of psychological processes in the general scheme of things, Aristotle made a specific contribution to psychological theory in his discussion of memory, particularly in his famous statement of the principles of association. These principles -association by contrast, by similarity, and by contiguity in time and space- were given as empirical rules. In the apparently fortuitous way in which [p. 33] ideas present themselves, Aristotle saw not chance, but law. Both the general conception of association and the particular rules he formulated exerted a great influence on the development of psychology centuries later.

Aristotle was the last of the major philosophers of antiquity. His death, in the last quarter of the fourth century, B.C. marks the close of the most original and productive period in Greek thought. Among the philosophies that flourished during the closing centuries of the ancient world, the views held by the Stoics and the Epicureans are the most interesting to psychology because of the contrasting attitudes they took on what might be considered a practical application of psychology. Both schools were occupied primarily with the problem of making the most of human life. In general, the Stoics stood for suppression, the Epicureans for expression of natural impulses. The Stoics believed in subduing desire to reason in the interests of virtue, which was to be sought for its own sake; the Epicureans believed in so ordering the expression of the natural impulses as to achieve happiness and tranquility. It is interesting to see the attitudes of these rival schools persisting down to the present day in modern theories about the control of human nature and the achievement of happiness and virtue.

Thus, wile psychology was still a part of philosophy, many of the patterns of thought that were to become prominent later had already appeared. This means neither that the later modes of thought were consciously borrowed from the earlier, nor that the discoveries of modern science were implicit in ancient speculations. It means rather that the same problems arose in human affairs, that they were perceived in the same ways, and that they gave rise to the same methods of attack. Then, as now, there were the problems of elements and form, of the parts and the whole, of the relation of mind and body, of function and structure, of [p. 34] process and substance, and of the control and management of human nature in the interests of achievement, virtue, and happiness.

From the standpoint of positive contributions to a scientific psychology, the Middle Ages are relatively unimportant. Their characteristic approach to psychological problems is found in the scholastic discussions about the nature and attributes of the soul. But, as every one knows, these discussions have often been cited as the very antithesis of scientific procedure. They began not with questions, but with accepted truth, based on authority. They proceeded not by using observation and induction, but by the elaborate unfolding of the implications of concepts and the logical deduction of consequences. Their final appeal was not to factual evidence, but to logical validity. Their method of thought has been used as the example par excellence of speculation in the air, of reasoning operating without a ballast of empirical fact. Yet the negative consequences of just this practice were of the utmost importance to science. Many of the characteristics of science -not, it is true, its essential nature, but an appreciable number of its accidental features- can be explained as a revolt from the excesses of that procedure. Its disgust at dogmatism and its dread of untested speculation are clearly survivals of emotional attitudes developed in the necessarily violent struggle against the appeal to authority and the practice of empty deduction that medieval scholasticism had made the accepted intellectual fashion.

The modern period in philosophy, however, is full of anticipations of the psychologies of the present. It contains, in fact, so many previsions of problems and theories which are being considered today that it is impossible to attempt a comprehensive survey of them. Many points of view interesting [p. 35] and suggestive in themselves must be passed over, and attention limited to those lines of thought which have some obvious historical relationship to the development of the scientific point of view in psychology. The most consecutive of these is the line of critical inquiry which ran through Descartes, the British empiricists, and Kant, and which had among its byproducts the growth of two schools of prescientific psychology, associationism in Great Britain and Herbartianism in Germany.

Very near the source of this movement was Rene Descartes, whose work in the first half of the seventeenth century is altogether typical of the early modern period in its revolt against the dogmatism of the scholastic tradition. Descartes himself, however, was anything but a rebel by temperament. He was a candid, very cautious, extraordinarily reasonable man who, though he had devoted himself to the pursuit of learning, discovered upon reaching maturity that there was nothing that he knew with certainty. Finding that he could doubt some of man's strongest beliefs, he deliberately undertook to use doubt as a method -to doubt everything it was possible to doubt, in the hope of arriving at the self-evident and the indubitable. He found that he could doubt a good deal: he could doubt the existence of God, the existence of the world, even the existence of his own body. The one thing he could not doubt was the fact that he was doubting, and the certainty that his doubt -i.e., his thought- existed gave him the foundation of his system. He stated his conviction in the famous formula "I think, therefore I am," and treated the proposition as an axiom. He thereby established the belief in his own existence as a thinking being, and then by a process of deductive reasoning, in the existence of God and the world, including his own physical body. His proof of the existence of God consists in the argument that he, the doubter and [p. 36] an imperfect being, nevertheless has the idea of God, a perfect being. And since the perfect cannot be dependent on the imperfect, it is necessary to assume the existence of God to account for the idea of God. Then, if God exists, the world must exist, for the ideas we perceive clearly and distinctly to be true -not the ideas we accept merely on the evidence of imagination and the senses- must be true, "for otherwise it could not be that God, who is wholly perfect and veracious, should have placed them in us." Thus Descartes came out at the end of his reasoning with everything that his doubt had destroyed. The difference between his first state and his last was not a difference in the objects of belief, but in the fact that they were now rationally established.

This point is significant. It means that though Descartes struck at the dogmatism of scholastic thought, he did not attack its intellectualistic procedures. His appeal was not to experience but to reason. If there is anything in Descartes more remarkable than his deliberate attempt at a thoroughgoing skepticism, it is his sober faith in the power of the human intellect to straighten out the existing confusion. Apparently Descartes did not consider the possibility that reason might be inadequate to the task. When he discovered that he could be sure of nothing, he summoned the aid of reason as a matter of course, and systematically set about the task of constructing a secure intellectual foundation for the universe. He struck a telling blow against medieval subservience to authority, but in doing so he utilized the deductive procedure that is as characteristic of medieval thought as is its dogmatism.

There are several of Descartes' specific views that are of particular interest to psychology. The most far-reaching of these is his dualism, which, though different from Plato's in its derivation, is similar in its effects. According to Descartes, there are two substances: mind and matter, the thinking [p. 37] substance and the extended substance. This conception involved him in some interesting and enlightening difficulties; he had separated mind and matter so completely that he found it hard to bring them together again into any working harmony. One outcome of this situation was the theory that animals, since they have no res cogitans, or thinking substance, are automata -an interpretation of complex living organisms that is especially interesting in the light of recent mechanistic interpretations of animal and human behavior. Descartes was, in fact, a thoroughgoing mechanist so far as the whole material world is concerned. He believed that all the actions of the human body -the movements of the muscles and tendons, the activities of respiration, even the processes of sensation- can be explained according to mechanical principles. It was Descartes, indeed, who introduced the concept of reflex action, which has been so widely used ever since in mechanistic explanations of bodily processes. Yet Descartes stopped short of making human beings mere automata; he believed that in each person there is a reasonable soul, a thinking substance, which has the power to direct and alter the mechanical course of events. This soul operates through the pineal gland at the base of the brain, and influences the movements of the body by acting on the animal spirits in the blood, which by entering one nerve or another determine which movement shall occur. But the action of the body itself, though subject to the direction of the soul, is strictly mechanical. The relation between mind and body, as Descartes saw it, is thus one of interaction. The mind acts on the body in the manner just described, and is acted upon by the body through its modes of sensation, emotion, and action. Just how two substances so totally different can influence each other Descartes failed to explain, but he stated the position of dualism and interactionism with the utmost clearness and thus reaffirmed [p. 38] the distinction between mind and matter in modern thought.

Another point in Descartes' teachings that has a rather direct bearing on psychology is his belief in innate ideas. Descartes, who was a mathematician as well as a philosopher, assumed that there are certain necessary truths or axioms which constitute the basis of demonstrable knowledge. These truths, he assumed, are inherent in man's nature, and when perceived are self-evident. Despite his intention to doubt everything, Descartes had not questioned the existence of innate ideas. The question, however, was raised by some of his critics, and attained such importance that it became the starting-point of the long line of inquiry about which the philosophers of Great Britain developed their critical empiricism.

One of these, an older contemporary of Descartes, was Thomas Hobbes, a blunt, hardheaded British Royalist, who wrote a number of treatises on human nature in which he paid particular attention to man's relations to the state. The Leviathan, published in 1651, two years after the execution of Charles I, was probably the most important of these. This book is primarily a political treatise, but running through its treatment of political problems is a tendency that is of special interest to psychology, the tendency to over rationalize human conduct. Hobbes' main purpose was to justify the absolute power of the ruler. He did so by explaining that first of all there is a natural impulse in all men to take what they want and what they can get. This impulse, however, leads inevitably to conflict. Every one is at war with every one else; nobody is safe; every one is to some extent defeated in his purposes. This intolerable situation is terminated when men, prompted by fear and self-interest, see that they can gain security, and more of [p. 39] the goods of life, by giving up their natural right to take whatever they can, and by receiving in return the assurance of protection from the aggressions and depredations of their fellowmen. But this state of affairs can be maintained only if there is a power strong enough to enforce it, and this power is created when the members of the state agree to hand over their rights and powers to one central authority. This voluntary agreement is the justification for the absolute power of the ruler.

From the standpoint of psychology, a significant point in Hobbes' discussion is the use it makes of the notion of the "rational man," the notion that human conduct is dominated by reason. Though fear and self-interest, it is true, are regarded as the motives of action, reason suggests the "convenient articles of peace" and guides the course of conduct. The fear and self-interest are calculating, not blindly impulsive. It is, in other words, reason that manages the situation. Hobbes thus supplies another illustration of the common tendency to think of man as the reasoning animal, to explain the course of his actions as planned and foreseen, rather than as determined by chance; as directed finally by intellectual considerations, rather than by anything so unrational as feeling, emotion, and the accidents of life. Psychology is continually discovering that human beings like to assign reason the major role in their affairs; and it is peculiarly indicative of the strength of this tendency that it should appear in the realistic and cynical Hobbes, who has never been accused of attempting to draw a picture of human nature that is even mildly flattering.

But Hobbes' attitude toward the rational man was less an expression of himself than of the current mode of thought. It is significant in fact because it is an expression of the current mode. Hobbes' other contributions to psychology, however, mark out new paths. One of these is a general treatment [p. 40] of psychological processes which places them unequivocally in the stream of natural events. Hobbes had evidently been impressed by the work of Galileo, and seizing upon the suggested possibility of a naturalistic explanation, he attempted to account for all human activity, not excepting the psychological, in terms of motion. Sensation, which is the source of knowledge, is motion communicated by the external object to the brain. Imagination and memory are continuations of that motion; "decaying sense" is Hobbes' term. The mind has no content, however complex, that is not reducible to these terms. Even the sequences of thought, however accidental they may seem, are matters of natural law. Just as ideas themselves are determined by objects acting on the senses, so the transitions from one idea to another are determined by the relations they bear to each other in the original experience. This, of course, implies the basic principle of associationism: that one idea succeeds another not by chance but according to law. It was in this connection that Hobbes made a distinction between the two kinds of thought which have since been called free and controlled association. In the former, "thoughts are said to wander and seem impertinent to one another as in a dream"; in the latter there is some "passionate thought to govern and direct those that follow to itself." And yet, even in the apparently "wild ranging" of free association, Hobbes regarded the course of thought as determined. His psychology was [reductive,] materialistic, mechanistic, and deterministic throughout, a psychology in which even the most casual imaginings of man take their place in the orderly stream of events that constitute the world of nature.

It was not Hobbes, however, but his successor, John Locke, who raised the specific question that gave the impetus to British empiricism. From the standpoint of psychology, Locke stands at the starting-point of two movements. One, [p. 41] a line of critical inquiry carried on by Berkeley, Hume, and Kant, led to the destruction of the old rational psychology, that system of thought which, claiming a knowledge of the soul that was based on intuition and deduction, held that its knowledge was demonstrable as absolutely valid. The other was a more positive movement, which, expressing itself partly in the commonsense philosophy of the Scottish school, and partly in the teachings of the British associationists, led to a psychology that, though it was empirical as opposed to rational, stopped just short of becoming experimental.

The origin of Locke's problem is singularly appropriate. During a discussion with a few friends, it occurred to him that, since they were making no progress toward a solution, their first task ought to be to inquire into the nature of the understanding itself; to find out what matters it was capable of coping with, and what matters lay outside its scope. He suggested the problem, therefore, and agreed to present his thoughts on the topic at the next meeting of the group. Accordingly, he assembled his reflections on the subject for a brief paper, but this question, so shrewdly put, occupied him at intervals for twenty years of his very busy life. His final answer was given in the Essay concerning Human Understanding, published in 1690, when the author was fifty-eight years old.

Locke's problem, it will be noted, was not strictly psychological. Like the Greek philosophers, he was interested chiefly in the validity of knowledge; he was not examining the process of knowledge for its own sake. Only incidentally was his question "How do we know?" Essentially it was "What are we justified in accepting as genuine knowledge?" Primarily Locke's enterprise was an epistemological inquiry, but it turned attention to psychological problems.

When Locke examined the constitution of knowledge, he [p. 42] became convinced that all knowledge is derived from a single source, experience. But experience itself is of two sorts: some of it comes through sensation, some through reflection; some, in other words, comes through impressions from sensible objects in the external world, some through our awareness of the operations of our own minds. There are no other sources of knowledge. There are no innate ideas. That we do not start with a stock in trade of axioms or necessary truths is a point on which Locke is especially insistent. For page after careful page, he wages war against the notion that the mind is equipped with ideas which are independent of experience. Originally the mind is "white paper, void of characters, without any ideas." "Nothing in the intellect which was not first in the senses" is sometimes given as a statement of Locke's theory of knowledge. Sensation and reflection give us simple ideas, and simple ideas are the stuff of which all human thought is made.

To Locke all this was interesting and important because it indicated the capacities, and especially the limitations, of the human understanding. It gave him a criterion for testing the validity of knowledge. If an idea could be traced to its legitimate source, experience, it was acceptable; if no basis in experience could be found, it was specious -it had slipped in surreptitiously and had no foundation in fact. Locke's analysis of knowledge, however, had a psychological as well as an epistemological significance. It established in the thought of the time an atomistic conception of mind -a conception of mind as composed of units combined in various ways. It provided a set of simple ideas and a plan of metal organization which suggested that it is necessary only to discover how the simple ideas are put together in order to understand the human mind and all its possibilities. It is this positive side of Locke's teaching, this promise of making the mind intelligible in terms of units and their combinations, [p. 43] which led to the development of the school of psychological associationism.

But the negative or critical sides of Locke's thought also had important consequences. Locke's explanation of knowledge as composed of simple ideas, together with his attempt to account for knowledge of a real external world, drove him to a distinction between primary and secondary qualities. Primary qualities are those like motion, extension, figure, solidity, and number, which exist in the object itself. Secondary qualities are those like colors, tastes, and sounds, which depend on the sensory equipment in the organism. Thus, solidity really exists in the external world, but color does not, for color is something we ourselves contribute because our sense-organs are what they are. [This formal doctrine of primary and secondary qualities has subsequently become known as the "Representationalist theory" of indirect perception]

But is there any real difference between primary and secondary qualities? This question was raised by George Berkeley, a brilliant young Irishman, who later became Bishop of Cloyne. Berkeley put this question in 1710 in A Treatise concerning the Principles of Human Knowledge. In entire agreement with Locke, he pointed out that our knowledge of the external world comes through the senses. All that we know about an apple, for instance, is what our senses tell us. We know that it is red and sweet and fragrant because we have sensations of vision and taste and smell; we know that it is solid and extended because we have sensations of touch -because we feel sensations in the skin and muscles when it offers resistance to pressure, and when we make movements of the muscles in handling it. Is there any difference, then, between our knowledge of solidity and extension, which are primary qualities, and of redness and fragrance, which are secondary? All are derived from sensation and from no other source. Locke himself said: "Let the eye not see light or colors, nor the ear hear sound; let the palate not taste, nor the nose smell; and all colors, tastes, [p. 44] odors, and sounds, as they are such particular ideas, vanish and cease." Berkeley simply carried Locke's reasoning a step further. Solidity, extension, and all other primary qualities are likewise known only through perception, and are in exactly the same case as are secondary qualities. The apple is all sensation; it is nothing but sensation; its esse is percipi. That to be consists in being perceived is Berkeley's central doctrine, and in making his point, he appeals directly to experience. Confident that the feat is impossible, he asks the reader to imagine any of the qualities of objects -primary as well as secondary- without a mind that perceives them. Take away the perception, he says, and the quality disappears. As there can be no red without the perception of red, there can be no hardness without the perception of hardness. To put the point plainly, there is no material substance. We know only sensory qualities; we never get beyond them; and if we try to get beyond them and infer that there is a substance underlying them, something that supports them and in which they inhere, we are really adding nothing. We are simply making an empty declaration, utterly gratuitous and baseless, and in the end inconceivable. Locke, who stuck to common sense, retained a core of material substance in the external world; Berkeley, who stuck to a course of logical reasoning, waved it aside. [This emphasis on the immateriality of perceived phenomena eventually garnished the term "phenomenalism" for Berkeley's epistemological position; and also sets it apart from Locke's indirect, Objective Idealist, form of representationalism -which grants the materiality of perceived objects]

....Berkeley did not blink [, however, from attempting to explain] the difference between perceived objects and imagined ones. The former, he said, are independent of our volition; they are there [i.e., experienced] whether we choose or not; furthermore, they have an order and a coherence and a steadiness that we do not impose upon them. They are not subject to our own whims; they have a reality outside us. But this reality, Berkeley insists, cannot be corporeal. His analysis has shown that material substance is unreal; that external objects have no core of [p. 45] bodily substance; that no such core is necessary or even imaginable. Still, the coerciveness, independence, order, and stability of [experienced] objects are facts that must be accounted for; and Berkeley explains these qualities by saying that they reside in the perceiving mind of God -a concept that to him is free from the contradiction and the emptiness which he finds in the notion of material substance. As our ideas are to our minds, the whole order of nature is to God's mind. The existence of things, finally, consists in God's perception. To Berkeley, this was the essential point of his whole treatise. Like Locke, he was interested in his psychological analysis chiefly for the sake of its metaphysical outcome. But from the standpoint of historical development, the positive [metaphysical] side of his thinking has had little influence. It was the critical, destructive [phenomenalist] side of his philosophy that bore fruit in subsequent thought.

And yet, in spite of the fact that his interests were primarily metaphysical, Berkeley is the author of what is probably the first strictly psychological treatise -it may almost be said, of the first psychological monograph. His New Theory of Vision, published a year before the Treatise, attacks a psychological problem for its own sake, the problem of showing how "we perceive by sight, the distance, magnitude, and situation of objects." Berkeley undertakes in this study to show how we perceive distance or the third dimension, and he does so not because of any ethical or philosophical implications of the problem, but simply because the problem exists. Berkeley remarks that we cannot see distance directly because "distance being a line directed endwise to the eye, it projects only one point in the fund of the eye. Which point remains invariably the same whether the distance be longer or shorter." His explanation is that we perceive distance as a result of experience; more specifically, that certain visual impressions become associated with [p. 46] the sensations of touch and movement which occur when we make the necessary ocular adjustments in looking at near or far objects, and when we move our bodies or parts or our bodies in approaching or withdrawing from seen objects. This is probably the first application of the principle of association to a strictly psychological problem. Perhaps it should be mentioned parenthetically that Berkeley seemed to an unusual degree aware of the role of tactual and muscular sensations in psychological processes. For some reason, the sensations that make us aware of our own bodily movements are more likely to be overlooked than are those from the eye and the ear, and they attract general notice rather late in the development of psychology. And yet Berkeley utilized these sensations not only to account for the perception of distance, but to show that primary qualities, like secondary ones, consist ultimately in being sensed or perceived. The recognition of tactual and muscular sensations was therefore involved in the central doctrine of his philosophy.

Berkeley raised still another distinctly psychological problem, that of the existence of abstract ideas. In this case, however, the problem was undertaken because of its bearing on his metaphysical position. Locke, who had attacked the notion of innate ideas, had nevertheless recognized the existence of abstract ideas. But Berkeley denied the existence of abstract ideas, and he did so avowedly because of the bearing of this question on his contention that the notion of material substance is, when closely scrutinized, unthinkable. Berkeley's discussion is interesting from the standpoint of psychology, because he evidently identifies [equates] idea and image. Since he cannot form the idea of a man unless it be of "either a white, or a black, or a tawny, a straight or a crooked, a tall, or a low, or middle sized man," since he cannot form an idea of motion that is distinct from the [p. 47] body moving, and which is neither swift nor slow, curvilinear nor rectilinear, he considers that belief in abstract [i.e., nonspecific, decontextualized, generalized] ideas a "delusion of words." Though the point did not come out explicitly in the discussion, the difference between Berkeley and Locke on the possibility of abstract ideas really involved the question of the possibility of imageless thought. In the background were the questions: Must our ideas be copies of the things we are thinking about? Or if not that, must they contain some sensory content that in some way represents them? Can there be thoughts that have no sensory content at all, and which nevertheless have a genuine function as thought? Such questions as these were implied in Berkeley's inquiry; but they did not emerge as strictly psychological problems until two centuries later, when the imageless-thought controversy gave them the clearness of formulation that an experimental setting made possible.

Berkeley, of course, had carried Locke's critical analysis much farther than Locke had intended, but it was carried still farther by the Scottish philosopher, David Hume. Berkeley had disposed of the concept of material substance, denying the objective existence of things or objects outside experiencing minds or [God's] Mind. He had not, however, doubted the existence of mind itself, nor had he questioned the principle of causality. Rather he had assumed both, giving as the cause of the characteristics that distinguish perceptions from images, the divine mind which perceives them. As Berkeley left it, the universe still had some support; it was not a mere kaleidoscope of ideas. This support Hume proceeded to remove by questioning both the existence of the thinking self and the principle of causality.

Hume's criticism of the self is strikingly like Berkeley's criticism of material substance. When he tries to examine the self, Hume explains, he finds nothing but particular perceptions -love or hate, pleasure or pain, light or shade- [p. 48] noting to correspond to the self that the philosophers describe as a simple substance persisting through all change. In the idea of the self he sees a baseless and unnecessary addition to observed facts, the same kind of groundless notion that Berkeley found in material substance.

In a similar manner, Hume disposes of causality. The idea of cause, he explains, contains the idea of necessary connection, but when he traces the idea back to the experiences from which it is presumably derived, he finds nothing of necessity, only contiguity and succession. Experience gives us nothing more than invariable temporal sequence; all that we actually see is that when A happens, B follows. The necessity that the notion of causality implies is nowhere to be found in experience. The idea of causation therefore has no objective validity. It is produced in the mind; it is not discovered in the object. The fact remains, however, that we have a strong belief in causality, a fact which Hume never denies, and which he attempts to explain. Our belief in causality he finds to be a matter of custom, or habit, or very strong association. All that we observe is that certain sequences invariably occur, but these sequences, repeated again and again, produce in the mind a strong disposition to connect the events that form them. If A has always been followed by B, the occurrence of A leads us to expect B. The principle of causality therefore is based on a habit or tendency or disposition in ourselves; there is no warrant that it is objectively valid.

Thus under Hume's criticism, the world collapsed into an aggregate of ideas, supported by no substance and connected by no necessity. Berkeley's criticism had removed material substance, but had left a world of orderly events, dependent on a spiritual substance. By applying the same kind of criticism that Berkeley himself used, Hume demolished whatever of order and substantiality Berkeley had left in [p. 49] the world. The world as Hume saw it was a drift of ideas, without connection, without permanence, without unity, without meaning, simply present and passing. Even to its author, there was something strained and unnatural in this conception. No one saw more clearly than Hume the discrepancy between the extreme skepticism to which his reasoning had led him and demands of everyday life; and he offered no logical reconciliation. "I dine, I play a game of backgammon, I converse, and am merry with my friends"; so runs one of his comments, "and when, after three or four hours' amusement, I return to these speculations, they appear so cold and strained, and ridiculous, that I cannot find it in my heart to enter into them any farther." [In other words, the logical endpoint of Hume's albeit "logical" and sensation-based "skeptical" epistemology is an impractical solipsism]

Hume's successor in the critical movement was Immanuel Kant. But Kant found it impossible to accept with Hume's equanimity the outcome of Hume's destructive speculations. Kant could not stop with a situation in which the cogitations of the philosopher's study led to one view of the world and the demands of daily life to another. After all, Kant insisted, the world as we know it is a world of order; and this order, as Hume has clearly shown, cannot be derived from [mere sensory] experience. Neither can it be denied. It must then be derived from the mind itself, which, instead of reflecting the order of an external world, imposes its own laws upon nature. This is the thesis which in 1781 Kant announce in the Critique of Pure Reason, a book that made its author, up to that time an obscure professor in the University of Königsberg, the leading figure in the philosophical world of the day.

Experience, according to Kant, is derived from two sources: things as they are in themselves, and the mind. Experience is a product, a creation, of the two. Experience begins when things in themselves act upon the sense, but the moment this happens, an elaborate machinery is set going [p. 50] that makes it forever impossible for us to know things as they are, independent of our ways of knowing. Not only is the content of our experience determined by our modes of sensation -a fact that had been sufficiently recognized- but its very form and arrangement, its order and organization, are determined by the mind that receives and molds it. Nothing can enter into our experience without arranging itself according to the laws of our nature: first, according to the forms of immediate perception or intuition, space and time, which are purely subjective; second, according to the logical order imposed by the categories of the understanding, of which causality is one; and finally, into that unified world which is made necessary by the logical unity of the ego that perceives all the contents of experience. The order and coherence that we see in nature are the order and coherence we impose upon nature. Things in themselves [noumenon], therefore, can never be known as they are; they can be known only as they appear in [sensory-based] experience [phenomena], determined by the [a priori] forms of our thought [which allow inference from sensations]. Nature can never be discovered; reality, as it exists outside our experience, is forever beyond our reach. True metaphysical [i.e., absolute or complete] knowledge is impossible; only empirical knowledge is obtainable. We can never know the world as it is in itself, as it exists outside our ways of knowing. But neither can we know the experiencing soul directly -and this is the point which is particularly significant for psychology -for we know it not as it is in itself, but only as it appears in time, one of our forms of intuition. It is as impossible to know the soul as to know the world. Therefore rational psychology, the psychology that claimed to have direct knowledge of the soul, is as impossible as metaphysics. There remains only an empirical psychology, which cannot attempt to answer ultimate questions, any more than can an empirical science of physical nature. Neither the world nor the self [p. 51] can be known to the human mind in its true nature. It is useless to try to attain ultimate and absolute truth about either. Psychology, like physics, is an empirical science, or as Kant would say, a mere empirical science.

[In other words, the phenomenalist endpoint of Kant's bi-directional epistemology (of interaction between external objects and the a priori contents of the mind), indicates that his attempt to reassert a rationalist based representational theory of visual perception ultimately failed]

Kant himself wrote, under the title of Anthropology, what amounted to an empirical psychology; but in his opinion psychology could never take high rank even as an empirical science, because its material is not reducible to quantitative terms and is therefore not susceptible of the exactness of treatment that characterizes true science. It was not as a psychologists, however, that Kant influenced psychology. It was as a critical philosopher announcing that the pretensions of rational psychology are groundless. His importance to psychology lies in the fact that he stands at the end of a line of critical inquiry in which, by examining its own instrument, the human intellect, philosophy made it increasingly clear that psychology, whatever it may be, is not metaphysics. Descartes started the movement by his appeal from authority to reason. Hobbes, Locke, Berkeley, and Hume, carrying their analyses through successive stages, arrived at a point where no absolute justification could be given for the authority of the intellect. Kant, while affirming the role of intellect in experience, asserted that it was valid only within the realm of experience, and that all knowledge which pretended to transcend [empirical] experience, which pretended to be absolute and ultimately certain, was groundless. Rational psychology was part of this baseless knowledge. There was no more hope in psychology than in physics for absolute and certain knowledge. Psychology, like physics, could exist only as an empirical science.

In the meantime, the interest in the psychological aspects of experience itself did not wait for this metaphysical justification. It will be remembered that side by side with the [p. 52] critique of knowledge, there was another movement, more positive in character, which had its source in the empirical analysis of knowledge that Locke and his successors employed. One part of this movement expressed itself in the commonsense philosophy of the Scottish school. Its point of departure was Hume, as was Kant's, but the Scottish philosophers disposed of their distinguished fellow-countrymen far more summarily than did the painstaking Kant. The sturdy Scotch realists took their stand in a solid world that refused to be dispelled by subtle speculations. Subtle speculation was far less real to them than the objects of sense and of daily life, and if rational analysis left a picture of things so obviously at variance with reality as it appears to common sense, they considered it so much the worse for rational analysis. Thomas Reid, professor of philosophy at Edinburgh and a contemporary of Hume, was the founder of the school. He grounded his position on "instinct" and "common sense." The senses, he declared, make us immediately aware of an external world and they arouse in us an "invincible belief" in the existence of external objects. Though it is true that no reason can be given for our belief, its presence is indisputable, and the belief itself must therefore be explained as due to an original and instinctive tendency implanted in the human constitution. It has been suggested that the views of Hume and Reid are not after all very different, since both men hold that belief has no rational basis, but nevertheless exists. The story is told that when this point was suggested to Dr. Thomas Brown, one of Reid's followers, Brown replied: "Yes, Reid bawled [screamed] out we must believe in an outward world; but added in a whisper, we can give no reason for our belief. Hume cries out we can give no reason for such a notion; and whispers, I known we cannot get rid of it." [p. 53]

But the difference in emphasis had tremendous practical consequences. The attitude of the commonsense school not only turned attention to the world of empirical fact, but legitimized that direction of attention. In doing so, it adopted the position that is essentially the one science shares with commonsense -that of taking for granted, as a starting-point, the world as it appears to naive perception. The commonsense philosophy also took up the case for revealed religion. It was, indeed, one of the aims of the Scottish school to protest against those implications of Hume's skepticism which might undermine religious faith. To assert that faith and belief are legitimate and necessary attitudes toward the external world was to take a step toward justifying those attitudes toward religion. Religion for the Scottish school meant Calvinism, and since the Scottish school a little later joined forces with British associationism, an alliance was formed that is of special interest to American psychology. For a psychology that blended harmoniously with Calvinism was peculiarly adapted to the needs of the first American colleges. It was, in fact, this psychology -British associationism tinged with Scottish common sense- which was generally taught in the early, devout days of American education, when psychology was included in the college curriculum as mental philosophy, when philosophy was, as a rule, taught by the president of the college, and when the president was extremely likely to have been trained for the Christian ministry in one of the Calvinistic denominations. It was this kind of psychology which was in possession of the field when James and Titchener introduced their respective innovations.

But British associationism was derived even more directly than was the philosophy of the Scottish school from the mode of thought that characterized Locke and his successors. It is difficult to name the founder of associationism -it may [p. 54] have been Hobbes or Locke or Berkeley or Hume- but there can be no doubt that in the work of [David] Hartley the basic doctrine was formulated with all the definiteness and explicitness that any school could require. Hartley, like Reid, was a contemporary of Hume. By profession he was a physician, and perhaps he gained from his profession the interest, not always found in other associationists, in the physiological aspects of the problem. According to Hartley, there are two orders of events to be taken into account, the mental and the physical. These two orders are not identical, but run parallel to each other, so that a change in one is accompanied by a change in the other. On the mental side, there are sensations and ideas; on the physical side, there are vibrations and vibratiuncules. Vibrations are exceedingly small motions in the particles of the nervous system; vibratiuncules are even smaller motions of the same sort, which occur only in the brain. While sensations involve the action of both nerves and brain, ideas require the action only of the brain. The vibrations, which are active in sensation, initiate the vibratiuncules, which are active in ideation. There is thus a direct connection between sensation and idea. The general law of association is that if sensations have often been experienced together, the corresponding ideas will tend to occur together; if A has been associated with B, C, and D in sensory experience, the sensory experience A, occurring alone, will tend to arouse the ideas of b, c, and d, which accompanied it. Association may be either successive or simultaneous. The former determines the course of thought in time; the latter accounts for the formation of complex ideas. These few principles form the basis of associationism. Naturally, the associationists differed among themselves in particulars. Some inclined to one form of association, some to another; some recognized association by similarity, others did not; and some attempted to reconcile a belief in the [p. 55] unity of the self with an account of mental processes derived from a Lockian atomism. But whatever the modifications introduced by individuals, the main line of development was an attempt to show, sometimes in great detail, the starting with ideas and the general principle of association, it is possible to account for all mental formations, whatever their degree of complexity.

In Dr. Thomas Brown, the Scottish school and British associationism were very definitely combined. Brown, who had studied under Dugal Stewart, Reid's successor at Edinburgh, himself became professor of philosophy there. Following the Scottish school, which accepted selves as it accepted an external world, Brown upheld a psychology that emphasized the unity of the mind. At the same time he believed that the analysis offered by the British empiricists had much to contribute to the knowledge of the particular ways in which the mind works. He is known in psychology chiefly for his attempt to formulate the specific conditions under which the general principle of association operates. The laws of recency, frequency, and intensity -that much used trio- are among them.

After Brown, the main line of succession runs through Sir William Hamilton to the Mills, Spencer, and Bain, who represent associationism at its height. Sir William Hamilton, a remarkably able man, was primarily a philosopher and a logician. He is best known in psychology for his concept of "complete redintegration," the tendency of an idea to reinstate in the mind all its concomitants in the original experience. James Mill is sometimes cited as the associationist par excellence, for in his writings the associationistic principles were applied with such thoroughness and in such detail that their limitations became apparent along with their possibilities. Mill was indefatigable in his endeavor to show that the associative processes are adequate to the [p. 56] highest complexities in mental life. His remarks on the idea of Everything are often quoted as an example of the lengths to which he was willing to push his principle.

"Brick is one complex idea," he wrote, "mortar is another complex idea; these ideas, with ideas of position and quantity, compose my idea of a wall. My idea of a plank is a complex idea, my idea of a rafter is a complex idea, my idea of a nail is a complex idea. These united with the same ideas of position and quantity, compose my duplex idea of a floor. In the same manner, my complex ideas of glass, wood, and others, compose my duplex idea of a window; and these duplex ideas, united together compose my idea of a house which is made up of various duplex ideas. How many complex, or duplex ideas, are all united in the idea of furniture? How many more in the idea of merchandise? How many more in the idea called Everything?"

John Stuart Mill, the son of James Mill, found difficulty in explaining complex ideas in terms of simpler ideas "united together" even if it were granted, as his father granted, that the elements do not retain their distinctness. The younger Mill, however, remained an associationist, at least nominally, and overcame his difficulty by means of the concept of "mental chemistry." Complex ideas, he said, are not always matters of composition; they may be said to result from or to be generated by the simple ideas, not to consist of them, just as in chemical compounds something appears in the compound that is not present in the elements taken separately. As the sensation of white is not composed of the seven prismatic colors, but is generated by them, so a complex idea may be generated by, not composed of, simple ideas. In the Mills, too, the principles of Bentham's utilitarianism were combined with the doctrines of associationism, with the result that associationism carried along, as part of [p. 57] itself, a conception of motivation that explains human conduct in the somewhat over rational terms of "enlightened self-interest," a belief that human actions can be accounted for in terms of seeking pleasure and avoiding pain.

Herbert Spencer, twelve years younger than John Stuart Mill, is important in associationism chiefly because he adopted the standpoint of evolution in his psychological thinking. Spencer, who believed in the inheritance of acquired characteristics, maintained that complex traits are evolved in the race as complex ideas are developed from simple ones in the individual -that instincts, for example, are built up from reflexes. Alexander Bain, a contemporary of Spencer, is best known for his two volumes The Senses and the Intellect and The Emotions and the Will. His importance lies not so much in any specific contribution, not so much in any particular theory or doctrine, as in the fact that his two books constitute a systematic and scholarly exposition of classic associationism at its height. These books, published just after the middle of the nineteenth century, mark the culmination of British associationism and therefore may be regarded as one of the landmarks in the history of psychology.

In a sense, associationism was the first "school" of psychology. Its adherents were a group of men who worked from a common point of view and who saw the major problems of psychology in very much the same way. They did not agree on all points -on the relation of idea and sensation, for example, and on such points as whether association by similarity should be recognized along with association by contiguity -but they were all occupied with the same kinds of materials and their thought represents a continuous development. And very definitely, the associationists were writing psychology rather than philosophy. They surveyed their problems in the matter-of-fact manner of natural [p. 58] science, seeking their subject-matter in actual experience, in observable formations of thought. In their hands, the mind lost much of its aura of mystery and ineffability, and psychology became downright, unpretentious, and empirical. The main business of the school was that which everywhere occupies science -the attempt to discover natural laws in a world of observable, natural events.

So far little has been said of the Continental philosophers. Only Descartes and Kant have been mentioned, and they have been included because of the connections they made with the critical and empirical thought of Great Britain. Even more than their British contemporaries the philosophers of the mainland were interested only incidentally in psychology. Certainly there was, on the Continent, no continuous line of psychological inquiry persisting, as did British empiricism and associationism, through changing personalities and problems. Still, many of the conceptions of the Continental philosophers, though they were evolved in attempts to solve problems not in themselves psychological, have definitely influenced psychology.

One of these conceptions is the parallelism of Spinoza, a contemporary of Descartes, and like Descartes, the author of one of the great rationalistic systems of the seventeenth century. In some of his writings Spinoza dealt with distinctly psychological problems; but, strangely enough, it is only through his metaphysical doctrine of parallelism that he is represented in psychology at present. And even this doctrine has been used in psychology in a manner by no means representative of its author's thought. For Spinoza's parallelism was part of his conception of reality as an all-embracing unity, of a reality that, though it has an infinite number of attributes, is itself one, and appears to human perception through only two of its attributes, matter and mind [a.k.a. Double-Aspect Theory]. [p. 59] Fundamentally Spinoza was a monist; the belief in the unity of the world, a belief that lay at the basis of his philosophy, was something for which he felt both an emotional and an intellectual need. But in psychology, the concept of parallelism, taken out of the context that gave it its significance to its author, has been used by some schools as a convenient device for disposing of the mind-body problem. Its merit, as such a device, lies in the fact that it enables an investigator to take into account both physical and mental happenings and to note their relationship empirically without becoming involved in the metaphysics of their ultimate relation.... The mental and the physical can be treated as two streams of events, neither acting as the cause of the other, but together constituting a system in which a change in one is regularly accompanied by a change in the other. This conception makes it possible to preserve the dualism of mind and matter and yet to avoid the difficulties of interactionism. A somewhat similar mode of thought is found in the occasionalism of Malebranche and the preestablished harmony of Leibniz, both of whom, like Spinoza, represent the rationalism of the seventeenth century.

Leibniz, in fact, following Descartes and Spinoza, produced the last of the three great rationalistic systems of the century. His conception of reality was that of a "pulverized universe," composed of an infinite number of unextended, immaterial centers of force called monads. His mental habit of "pulverizing" is also present in his contributions to the special sciences; in the infinitesimals of the calculus, of which he was one of the inventors, and in the petites perceptions that are involved in one of his contributions to psychology. This doctrine of petites perceptions is virtually a doctrine of [p. 60] the unconscious, and of the continuity of the unconscious with the conscious. As the visible world is reducible to invisible monads, so our clear consciousness goes back to obscure consciousness or even to unconscious mental states. Leibniz used the roar of the sea to illustrate his meaning. That we hear this sound is an undeniable fact, yet the "little sounds" of which it must be composed -the sounds made by the individual waves that make up the sea- would not be heard if each one occurred alone. Nevertheless we must be affected a little by each single wave, for "otherwise we should not have a perception of a hundred thousand waves, for a hundred thousand nothings cannot make something." Perhaps modern psychology would, on the whole, prefer to explain this phenomenon in terms of the summation of stimuli, rather than in the terms of the summation of unconscious perceptions. But the significant point is that in Leibniz there is a definite recognition of unconscious mental processes, a realm of psychology that, it is hardly necessary to state, has occasioned the liveliest interest in the psychology of today. The doctrines of the psychoanalysts, however much they may differ in texture and character from the speculations of Leibniz, nevertheless have something in common with the precise reasoning and acute perceptions of one of the founders of the calculus.

Leibniz was interested, too, in the question of innate ideas. Locke, it will be remembered, denied their existence, but he based his argument on the assumption that such ideas are either present or absent, fully formed or nonexistent. Locke made much of the fact that the basic axioms are not present in the minds of children, of savages, and of the uneducated, and that they appear only when the individual has encountered the experiences that are capable of producing them. To Leibniz, all this might be true, and yet the concept of the mind as "white paper" or "tabula rasa" might not be [p. 61] the only possible explanation. He suggested "veined marble" as an alternative. As a block of marble may be so marked with veins as to make it more suitable for the figure of Hercules than for any other, so the human being may come into the world not with ideas fully formed, but with tendencies and predispositions that make the development of certain ideas highly probable and highly suitable to his nature. This conception is not unlike that of the loosely organized instincts, which is held by a number of psychologists today -the conception that certain modes of behavior are native, not in the sense that they emerge fully formed, perfect and with the machinelike regularity of a chain of reflexes, but in the sense of existing as tendencies to reaction, the details of which are acquired by a process of trial-and-error learning in response to the particulars of concrete situations. According to this way of thinking, the modes of action known as instincts are produced by two sets of factors, those involved in native constitution and those supplied by the environment.

In the eighteenth century, the rationalism of the seventeenth persisted, not as a tendency to form closed systems like those of Spinoza and Leibniz, but in the formalism, classicism, and pleasure in logical construction that characterized the thought of the period. In France, the two main lines of psychological thinking were attempts to push existing theories to their logical conclusions. One of these was represented by Lamettrie and Cabanis. Descartes, it has been noted, explained animals as automata and to very striking extent employed mechanistic principles in explaining human behavior. In 1748 Lamettrie [La Mettrie] in L'Homme Machine took the step that Descartes had not been willing to take and asserted that all the actions of human beings can be explained mechanistically. [La Mettrie's updated rationalist system dispensed with all but a nominal reference to the Cartesian "soul;" suggesting instead that both animals and human beings are physiological machines that think] Fifty years later, Cabanis a physician, reasserted and developed the same [sort of ] position. He [p. 62] declared that mind is merely a function of the body, more specifically of the brain, and that man's actions, including the most complicated operations of his intellect and the most exalted expressions of his moral nature, are nothing but the inevitable consequences of natural law operating in his physical being. [While La Mettrie can be classed along with Descartes as an interactive mind-body dualist, Cabanis adhered to a reductive form of mind-body monism. In Cabanis, like Hobbes before him, a Reductive] Materialism and mechanism were wholeheartedly accepted as constituting a thoroughly adequate explanation of human conduct.

Similarly Condillac, the Abbe of Mureaux, writing in the middle of the century, carried Locke's theory of knowledge to the extreme of absolute sensationalism. Locke had recognized two sources of knowledge: sensation and reflection. Condillac reduced all knowledge to one source: sensation. In presenting his case, he imagines a statue, constituted internally like a human being, but covered with a layer of marble. He first removes the marble from the nose and places a rose before it. The statue now has a sensation of smell; the fragrance of the rose constitutes its whole consciousness. The rose is removed and the sensation becomes memory. Other objects are placed before the statue -a violet, jasmine, asafetida. Their characteristic odors are now compared with the memory image of the rose and with the memory images of each other, with the result that some are perceived as agreeable, others are disagreeable. In this way desire occurs for some, aversion for others, and the passions and the will arise from the comparison of sensations pleasant and unpleasant. In a similar manner, all the operations of the intellect are produced; from the comparison of sensations pleasant and unpleasant. In a similar manner, all the operations of the intellect are produced; from the comparison of sensations arise reflection, judgment, abstraction, generalization, and reasoning. When other sensations are permitted the statue -sensations of taste, audition, vision, and touch- its psychic life becomes enormously more complex. The sense of touch is especially important, since it provides the basis of the idea of an object, and consequently of the external world. But [p. 63] all along, there is nothing that happens in the mind, there is no idea that the mind produces, which is not derived from sensation. The whole content of the mind, including its operations, is nothing but sensation that transforms itself in different ways. Condillac's thesis is the last word in sensationalism, and also in empiricism, in so far as that term denotes a theory of human knowledge as constituted by, and developing through, experience. But it is important to note that the system of Condillac is not empirical as opposed to rational. It is through and through a logical construction; it is not an account of observed facts. Perhaps it should be noted, too, that Condillac was not a materialist. Starting with his conviction that all mental facts are but transformed sensation, he might easily have believed, with the French materialists of his day, that sensation is produced by the operation of the sense organs and the brain. But the Abbe of Mureaux did not take this step. Clearly and definitely, he posited a soul, which though distinct from the body was, so far as his psychology was concerned, nothing but the bare capacity for sensation. [In terms of the mind-body issues, he stands closest to the phenomenalist positions of Berkeley and Hume] This point, however, is not especially important in his teachings. Condillac is remembered chiefly for his claim that sensation alone is sufficient to account for the most complex operations of the human mind.

In the same century, Jean Jacques Rousseau struck out on a radically different line of psychological thought. Rousseau's outstanding contribution to psychology was his insistence on the role of feeling and emotion in the human make-up. All along psychology had tended strongly to be intellectualistic. Empiricists and rationalists alike had analyzed the human being as if he were a creature whose primary business was knowing and thinking and discovering the truth. But to Rousseau, it was evident that man's true self is his emotional nature. The notion that man is essentially [p. 64] a creature of ideas and reason Rousseau regarded not only as false, but as a falsehood allied with all the evils of civilization, for Rousseau believed in the "noble savage" and a "return to nature," and regarded civilization as synonymous with slavery. In his eyes, the conventions and restrictions of society were false to man's deepest being; and by his very outrageousness in the eyes of his contemporaries -outrageousness that expressed itself in both words and deeds- Rousseau stood out in conspicuous protest against the formalism and artificiality of his age. His influence on psychology, however, is not easy to trace, for it was primarily as a political theorist and as an untrammeled individualist that he impressed the world. Certainly he does not fit into any of the well-defined lines of development that led to the science of psychology. But the man who sowed seeds of revolt in the France of the eighteenth century, and who protested against cold intellectualism in philosophy as against artificial conventionality in human society, made it impossible for psychology, even academic psychology, to remain wholly inattentive to the emotional side of man's nature. Emotion was to remain for a long time a dark and little-explored field, and psychology was to remain for many years predominantly intellectualistic. Still, the field of the emotions had been conspicuously indicated and its vast importance recognized.

But the currents that were sweeping psychology toward empiricism and naturalism were by no means without competition. They were in fact reactions against the thought that was officially established. In Germany, for example, there was Christian Wolff, a very paragon of rationalism, formalism, and dogmatism, whose school of thought flourished during the first half of the eighteenth century. Wolff is important to modern psychology largely because his teaching so clearly [p. 65] exemplify two habits of thought that had to be eradicated if psychology was ever to become a science. The first is the assumption that rational psychology has directed access to truth and reality in a way inaccessible to natural science; that absolute and demonstrable truth about the soul is attainable by the exercise of pure reason. This is the belief which, as has already been noted, Kant attacked from the standpoint of critical philosophy. The second is the conception of faculty psychology, the theory which holds that the soul is endowed with a number of powers -reasoning, remembering, and judging, for example- and which explains the specific performances of the mind in terms of the exercise of these faculties. There had been murmurs against faculty psychology from various quarters. The whole trend of British empiricism was obviously opposed to the conception, and Locke in particular raised his voice against it. But the faculty psychology of Germany in the eighteenth century, faculty psychology as it was represented by Wolff, met its most direct and effective adversary in the Herbartian psychology that displaced it. For Johann Friedrich Herbart aroused German interest in a mode of thought that definitely opposed and dispensed with faculties or powers of a soul. Herbart's psychology dealt with ideas or Vorstellungen, mental units somewhat similar to the simple ideas employed by the British associationists and also resembling the monads of Leibniz.

Herbart was Kant's successor at Königsberg, and as Kant's thought is a development of the critical side of British empirical philosophy, so Herbart's theories resemble the more positive side of the same movement. Like the British associationists, Herbart undertook to explain the most complex mental phenomena in terms of simple ideas. He was impressed by the thought that each idea has a certain degree of force, and emphasized the phenomena of inhibition as well [p. 66] as of association. Some mental facts he explained in terms of ideas that form compounds or blends, but he made inhibition, rather than association, the keynote of his system. Every idea, according to Herbart, has the tendency to maintain itself and to drive out ideas with which it is incompatible; and ideas vary in strength. When an idea encounters a stronger idea or group of ideas with which it is incompatible, it is thrust below the threshold of consciousness. The idea is not destroyed, however, but persists, though for the time it is unconscious. An idea that is in itself weak may gain admittance to consciousness, and maintain itself there, if the ideas above the threshold are congenial with it. Ideas already in possession of the field regularly repel uncongenial ideas; but uninhibited ideas, following the tendency of all ideas to rise to consciousness, are assimilated to the ideas in consciousness at the time. This process Herbart calls apperception, and the group of ideas into which the entering idea is introduced is known as the apperception mass. Mental life is thus mainly a struggle between ideas, each of which is active, each of which strives to attain and maintain a place in consciousness, and each of which tends to repel all ideas except those with which it is compatible.

This conception made it possible for Herbart to think of mental phenomena in terms of mental mechanics, and also in quantitative terms. Ideas vary both in time and in force or intensity; therefore psychological material offers two measurable independent variables. Applying his principle, Herbart wrote mathematical formulae to state the laws of the mind. He did not believe, however, that psychology could ever become experimental. It is interesting to note this fact as an indication of the very gradual manner in which the conception of psychology as a science evolved. Kant, in the latter half of the eighteenth century, though he regarded psychology as an empirical science, held that it could never become [p. 67] quantitative. Herbart, in the first half of the nineteenth century, believed that, though psychology might become quantitative, it could never become experimental. And yet it was partly through Herbart's conception of a quantitative psychology that psychology developed as an experimental science during the half-century following his death.

Herbart was also interested in education, and the widespread interest in applying his theory to the technique of teaching represents an important step toward the recognition of psychology as a science having something to contribute to the practical affairs of everyday life. For a time teachers everywhere were made acquainted with the famous five steps of the Herbartian technique, a method designed to build up in the pupil's mind an apperception mass suitable to the reception of the new material to be presented. Since Herbart's time, education and psychology have been closely related, and even today education is probably the most extensive branch of applied psychology.

It is important to note, too, that Herbart's psychology required the recognition of active unconscious processes. His conception of ideas as active, as persisting below the threshold of consciousness when inhibited, as continually striving to gain complete expression, and as contending against other ideas, is remarkably similar to the theories of the unconscious held by the psychoanalysts.

One of Herbart's disciples in psychology, W.F. Volkmann, wrote a textbook that bears much the same relation to Herbartian psychology as do Bain's two volumes to British associationism. It marks the culmination and presents the main contributions of a distinctive line of thought. Until experimental psychology was well established, Volkmann's Lehrbuch was widely used as a text in Germany. The date [p. 68] of its publication is 1856, a year after the appearance of The Senses and the Intellect and four years before the publication of The Emotions and the Will. It is interesting that, in about the middle of the century, Germany and Great Britain each produced a treatise presenting pre-experimental psychology in its most developed form. It is convenient, therefore, to consider these books as marking the close of one period in the history of psychology. William James, in commenting on the psychology of this period -a psychology as yet untouched by the experimental method- characterized Bain's work in words that might equally well be applied to Volkmann's, as "the last monument of the youth of our science, still untechnical and generally intelligible, like the Chemistry of Lavoisier, or Anatomy before the microscope was used."

In the middle of the nineteenth century, then, the long era of prescientific psychology came to a close. But during this era, psychology had come a long way. Beginning in speculations incidental to the practical problems of men and societies and to the search for ultimate truth, it had emerged as a body of knowledge studied for its own sake and existing in its own right. Among the Greeks, before psychology existed as a separate discipline, cosmology and epistemology, ethics, political theory and practical affairs, had all encountered questions concerning human nature. In this setting, however, such questions were not objects of a truly psychological interests. They were studied not for their own sake, but for the light they threw on other problems; they were studied because they were involved in attempts to understand the universe, or to work out a rational way of life. Besides, they were answered less on the basis of observation than on that of speculation, and the formulations that grew up about them were general and abstract. But for this [p. 69] very reason the early formulations stand out in the clear-cut outlines of rational concepts, as yet unblurred by the factual minutiae which are subsequently revealed by detailed observation, and which, as often as not, do not quite fit the conceptual mold. As a consequence, many of the problems that occupied the Greeks -problems of substance and process, of the parts and the whole, of mind and matter, of the individual and society, of proximate and final causes, of the mathematical approach to understanding, and of the general problem of knowledge- were formulated in such a way that they have served as fixed points of reference and as conceptual tools in the thought of psychology ever since.

In modern times, in western Europe, psychological problems again presented themselves. For a time philosophy was immensely concerned with the critique of knowledge, and out of that concern grew a lively psychological interest. In its broadest outlines the critical movement proceeded first from an appeal to ecclesiastical authority to an appeal to reason, and then from an appeal to reason as represented by metaphysics to an appeal to factual evidence as represented by science. One of the byproducts of this movement was an interest in psychology for its own sake, an interest that eventually expressed itself in the formation of two schools, associationism and Herbartianism. In the meantime particular psychological problems had arisen -problems of the possibility of innate and abstract ideas, of the nature of space perception, of the laws of association, of the relation of conscious and unconscious processes. A few fairly definite tendencies had emerged, among them the possibility of explaining human activities mechanistically, and of analyzing human experience atomistically. For the most part, during this period, psychology had over-intellectualized and over-rationalized its material, but it had also received strong intimations that the affective life of man might be very [p. 70] important, and had occasionally glimpsed the possibility that attention to the motor side of human nature might be enlightening. All this had taken place in a fashion far from systematic; still, a definite attitude and a definite method of approach had been evolved. By the middle of the nineteenth century psychology had learned to look upon its subject matter as a part of the world of nature and to seek to explain it in naturalistic terms. It was learning, too, to observe its material as well as to reflect upon it. In short, psychology was on the verge of becoming a science. In both subject matter and method it had become empirical; there remained only the step of becoming experimental.

Edna Heidbreder (1890-1985)