The psychology of reasoning

Preface

This little volume is based upon eight lectures given during my tenure of the Non-resident Lectureship in Psychology at Columbia University in January and February, 1909. The material has been somewhat rearranged and divided into chapters along more natural lines than was possible in the lectures.

My purpose is to give a brief statement of the place of the logical processes, particularly judgment and inference, in the concrete individual consciousness. Confining my discussion to the facts of the individual consciousness has compelled me to omit in large measure a consideration of the social aspects of reasoning and of the results of the outcome of reasoning in action. This omission has not been due to any failure to appreciate the importance of these two sides of the reasoning process. Kather, Professor Baldwin and Professor Dewey have left little to be said on these topics. For my own immediate purpose, also, society and action are but two of the sources from which are drawn the materials of reasoning, and are but two of the influences that serve to affect the course of reasoning. My problem has been to determine the ways in which reasoning has grown out of the simpler mental operations, and to discuss the uses that have been made of the materials in reasoning, without reference to the sources from which the materials have been drawn.

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PREFACE

Needless to say, I have neglected to discuss or even to mention many phases of the reasoning process that are important. I should have been very glad to find space for a psychological interpretation of fallacies and even for the more important forms of the syllogism, but space and the limitations imposed by a semi-popular audience made that impossible. I have also made no attempt to review the literature of either logic or psychology exhaustively even on the topics discussed. Even where my conclusions have grown out of the discussions of others, I have not always indicated the fact. I had space to do no more than summarize my own results and could cite the related work of others in but few instances.

I desire, however, to express my gratitude in general to the many writers from whom I have drawn inspiration. Perhaps I owe most to Bradley and Bosanquet, although I very much doubt if either would be willing to recognize me as a disciple. Of the more recent writers, Professors Dewey and Baldwin have been most helpful. I have received many suggestions and even more stimulus from my colleagues at the University of Michigan, and from my temporary colleagues at Columbia during the preparation of the manuscript, for which I am glad to acknowledge my indebtedness. Particularly I desire to thank Professor Cattell, whose invitation to give these lectures and to spend a half-year at Columbia at once gave the incentive and the leisure for the preparation of the lectures.

W. B. PlLLSBUBT.

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Contents

CHAPTER PAGE

' I. The Place op Reasoning in Psychology 1

II. Belief . . 23

Chapter II

The problem of belief is, in one of its aspects, the problem of truth. As such, discussions of belief have been numerous in the history of philosophy. The earliest form of the doctrine is closely intermingled with the discussions of the ultimate nature of things. One solution of this character we find in Plato's ideas whose existence gave certainty and stability to the more transient mental images. Later the discussions of the principle of sufficient reason in Leibniz, in Pascal and other logical writers approach the problem from a different point of view. Most of the tests were of a logical character alone. Pascal, to be sure, asserted that the clearness and definiteness of an idea gave it the warrant of truth. But it is only with the modern writers that we find the distinctly psychological problem put as we would put it, viz. : what is it that distinguishes the true from the false as psychological states? The first of 3 23 the modern writers to recognize the problem was Hume, who made belief depend upon the clearness or distinctness of ideas. The famous classification of mental states into impressions and ideas gives one answer to the question. Impressions must be accepted because they are intense, ideas may be denied if indistinct. Belief in ideas is also made to depend upon the strength of the associations that bring them into consciousness. For us the essential aspect of the theory is that it is the first to give an empirical basis for belief, to discover a criterion that lies in consciousness itself and is immediately open to investigation. Whatever credit may be due to Hume as the pioneer in the problem, as the first who recognized the possibility of answering the question in a scientific way, we must reject his explanation as at best but partial and incomplete. While in general vivid experiences are accepted and the faint and indefinite are doubted or rejected, there are notable exceptions. Many intense experiences are not believed to be real and a still larger number of faint impressions are at once given credence. Many detected hallucinations and illusions are of considerable intensity, while very many faint impressions are accepted at their first appearance without question. Certain of our beliefs then may depend in part upon the intensity and vividness of mental states, but this quality is not to be regarded as important. The exceptions are fully as important as the rule.

Bain formulated the next of the more significant types of theory. This has two independent criteria or explanations of belief. The first is his suggestion that to ask why we believe is to put the less important and less easily answered of two possible questions. For belief is the natural process, psychologically — is negative ; while doubt is positive. We believe everything that comes to consciousness unopposed. What requires explanation is doubt. Belief is the original process in the mind of the child. He does not doubt until he has accumulated a considerable amount of knowledge, until he has attained a relatively high stage in the development of intelligence. The other phase of this theory, that action is the test of belief, has had even a larger place historically. We believe anything that we are prepared to act upon. Belief comes with action however action may have been initiated. The first mentioned characteristic of belief may be derived from this, for from the beginning there is a natural tendency to respond to every sense impression. The main criticism to be passed upon Bain's theory affects its importance not its truth, and this applies only to the one criterion, action. There can be no doubt that when we act, we have ordinarily believed, but it may be a question whether we do not act because we believe, rather than believe because we act. In other words, one questions whether it is not much more important to explain action in terms of belief than to explain belief in terms of action.

What really concerns one is to determine the conditions of belief and of action, not to learn that one believes when one is ready to act. Action comes as the outgrowth of belief, or at most as another expression of the same set of conditions. What we are really anxious to determine is whether the idea is justifiable and likely to prove profitable before action has tested it. It might be urged too that belief often seems to grow through action, but in these cases it is probable that the resulting belief comes from the success of the action, rather than through the mere action itself. Some acts to be sure give rise to belief whose results are indifferent to belief; frequent repetition gives rise to a habit and the habitual movement distracts from consideration of circumstances that might arouse suspicion. This is not real belief. More usually however action serves like the experiment in science to confirm or refute. Not the act but the new evidence it furnishes is the source of belief. Of the two effects of action in furthering belief, one ordinarily gives mere pretense before the world, not real belief; the other derives its value not from the act itself, but from its results, an intellectual contribution that frequently destroys belief. We may readily grant the statement that action is an excellent test, — if we believe, we are willing to act in accordance with our belief, but action does not give rise to belief in any great number of cases. The second thesis that Bain upholds is at once important and true. Credulity is natural, doubt comes only at a relatively late stage in intellectual development. It follows that what needs discussion and interpretation is not belief but doubt, or disbelief, and we shall take advantage of the suggestion when we come to the positive, more constructive part of our discussion.

The third man to emphasize the importance of belief was Brentano, although he contributes little to the detailed analysis of the state as such. Brentano makes belief identical with judgment. Unlike Bain, he insists that mental states are at first indifferent to truth and must be judged before they become either true or false. Brentano positively declines to state in what the process of belief consists, or to give it any conditions. He argues strenuously that it is an unanalyzable process. "We believe and that is all that can be said. This can mean only that the process has not yet been analyzed or that Brentano does not care to undertake the task. He does in practice carry out his definition and makes judgment, or belief, one of the elements of mind on the same level as sensation or action. The truth or falsity of Brentano 's theory can be established only by successful completion or admitted failure of the analysis. While then in the recent history of the reasoning theories Brentano 's theory of judgment bulks large, his theory of belief deserves mention only from the importance he attaches to it in the total system.

One of the last great advances made is by James. Belief in the materials of perception is for James as for Hume dependent upon the intensity or vividness of the impression itself, upon the actions and emotions aroused and upon the degree to which it fits in with the habits of observation and action. Self -consistency is the most important condition of belief in matters of theory. Less important are the emotional and experiential aspects. The struggle between the different theories to satisfy our aesthetic and emotional needs eventuates in a compromise that is given belief. In one passage belief is defined as "the emotional reaction of the entire man upon an object." This definition seems, however, to be subordinated to the others. "We also find in James strong insistence upon the statement that one can by habitual endeavor make one's self believe what could not be believed at first. The most characteristic of all these conditions is the assertion that belief comes from the consistency of the object or statement with itself. The enlargement of this idea into the several systems of belief that are all consistent, each within itself, but inconsistent with each other, is significant of a tendency to demand for belief a wider consistency of the thing believed with other experiences.

If we look back over the theories of belief, we see that each man has accepted many elements from his predecessors but has subordinated them to the criteria that he was himself concerned to establish. If we combine all, we have the general statement that anything is believed that is intense or vivid, we believe that npon which we are willing to act and which harmonizes with our old habits and our emotional nature, provided always that it does not manifest inconsistencies within itself. So much we may accept as present in some degree in most states of belief. Any one except self -consistency may be absent and belief be present. We may believe in things that are not sensuously clear or vivid, we may even believe statements that are opposed to our habitual emotions and habits, if they are presented under new and striking conditions. We probably do not believe anything that we are not willing to act upon, but it is a question whether that tells us more of the conditions of belief or of the conditions of action. The objection to the theories mentioned is not that each does not contain some truth but that, taken together, they do not cover all cases of belief. In some instances we have belief where no one of them is present, and in others all may be present and belief still be absent. We have perceptions that are vivid and in harmony with our emotional mood and past habits of response, that we do not believe, and we hear stories that are all of these things and self -consistent as well that we still do not believe, while more rarely we believe assertions or accept experiences that possess none of these qualities.

We may begin our own constructive task with at least one fact gained from the history of the theories. This is Bain's assertion that belief is a negative and natural process that attaches to all mental states unless there is some good reason to the contrary; that one must seek reasons for doubt, not for belief. Anything that enters mind is normally at once accepted as true. Doubt or disbelief on the contrary must have some positive ground, and consequently arises only with sophistication and on the basis of positive evidence. In opposition to Brentano it seems that there is no moment when any perception or idea stands in consciousness as a mere given that is neither believed nor disbelieved. Introspection seems to show no moment of suspended judgment. An object or statement is accepted or rejected at once. On its entrance it stands before consciousness a thing believed, a thing denied belief or a thing in doubt. These attitudes may succeed one another ; a statement may be first believed, then disbelieved or doubted ; but never, so far as my experience goes, does it stand without evaluation as to its truth. Even when there is intentional suspension of judgment as a consequence of a warning that the question is difficult or that there is danger of being misled, what is suspended is not so much belief as the usual consequences of belief, action or the final stamp of approval. Brentano's assertion that in its initial stages the impression is indifferent to belief seems not to have been the result of actual experience or observation so much as a construction based on considerations of theory. If one were to suppose with Brentano that belief were an independent mental process without relation to anything else, it might be necessary or convenient to have two operations rather than one involved in the acceptance of an impression by consciousness. Brentano seems to have emphasized the needs of his psychological system rather than the facts of experience.

Accepting belief as a natural and immediate state of consciousness, we must begin our analysis of the state and its conditions not with belief, but with its opposite, disbelief, or the more definite quality, doubt. For disbelief seems usually to be belief in something else, doubt is unique. We may begin our study by observing an instance of doubt on the perceptual level where the phenomenon appears in its simplest, most analyzable form. One may take an old example in the illusion of reversible perspective. In the figure one sees at first glance a

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ZI7 flight of steps clearly and unambiguously drawn. A second glance shows that the figure is part of a broken wall under which one might take shelter from rain. The interpretation changes with the attitude. When one thinks of walking up and down on the steps, the steps reappear. As the attitude changes in this way from moment to moment, the interpretation varies. If one takes the experiment seriously, he is puzzled as long as the fluctuation continues. This is the typical attitude of doubt. The alternation is usually unpleasant when the problem is real. Complicated strain sensations are likely to arise and these add a new element to the unpleasantness. Qualitatively, then, doubt is unpleasant, and is marked by somewhat complicated strains. On the psychological side, the conditions of the fluctuations are the antecedent ideas or mental attitudes. When one is in a " flight of steps" attitude, one sees steps; when in a " broken wall" attitude, the overhanging wall dominates. The attitude is induced and changed by the words, but it might have changed spontaneously had the words been lacking. The fluctuation ceases and belief replaces doubt when the person looking at the picture learns that the drawing is perfectly plane; that the alternation is not due to perspective, and that the fluctuations arise from the ideas brought to bear on the interpretation of the presentation rather than in the presentation itself.

This simple illustration is typical of all cases of doubt in perception. It is very frequently possible to look at an object from more than one point of view. How it will be seen depends upon these points of view and the resulting interpretation will shift with the shifting attitude. As long as two points of view are possible or are actually operative in changing the interpretation, there will be doubt; when one or the other, or some third that transcends them, is definitely established, doubt vanishes and belief ensues. Very frequently alternation of interpretation is lacking; one context alone is dominant, and belief is present from the start. There is not even definite recognition of the possibility of doubt, so no conscious belief. The first interpretation persists and is taken as true without being consciously regarded as true or false.

It will be noted in a case of this kind that there is no third distinct process of disbelief. One takes the figure as either concave or convex, and believes either one or the other. It is possible, however, to express belief in one interpretation directly or indirectly as disbelief of the alternative interpretation. Whether one uses one form or the other, depends very largely upon the verbal context. If some one suggests that the figure above is concave, while one is seeing it convex, one is more likely to deny the concavity than to assert the convexity. The rejection of some other person's definite assertion is almost the only occasion for using the negative form. In this case the negative is altogether a matter of language, not of psychology. The only case in which disbelief is not really belief in something else is when no interpretation is satisfactory. Each suggestion is rejected. As a result, the negative form is used without any definite positive disposition of the object in consciousness. Then doubt unresolved gives rise to the negative. In any case the negative does not present a new psychological category. The only psychological processes are doubt and belief. We might note, too, that what is asserted of the logical negative by Bradley holds in the psychology of disbelief. Bradley, it will be recalled, asserts that one never gives a proposition the negative form except upon positive grounds; that one never makes a negative statement except upon some definite occasion. The same holds of disbelief. One would never assert disbelief in the existence of an object or of an interpretation of an object unless the interpretation had been asserted and rejected, or unless the interpretation had suggested itself to the speaker and it had later been seen that some other was more* stable. In the figure just discussed one would not say that it was not concave unless some one had suggested the possibility of seeing it as concave and one had not succeeded in the attempt. One does not assert disbelief at random. There are thousands of statements that might be denied of the figure, that it was red, virtuous, of curved lines, etc., but none of these are denied because they do not suggest themselves to anyone as possible.

Doubt concerning a statement of more general fact or theory has very much the same explanation. Doubt arises whenever a statement can be brought into two or more contexts -and changes as the context changes. Doubt, then, is an expression of the fluctuation that results from viewing a statement from different points of view. It carries with it, also, the implication that it is impossible to view it in one way for any length of time. Thus, the relation between body and mind is believed to be causal as long as one considers the similarities between the relation that subsists here and the relation of cause and effect as it is recognized in physics or in the practical world by the practical man. On the other hand, for some, at least, the idea refuses to fit into general experience when one emphasizes the differences between the physical and mental aspects, and attempts to apply the generally accepted principle of the conservation of energy. As long as the two ways of regarding the problem alternate, there will be doubt. Doubt ceases and we have belief whenever one way of regarding the subject vanishes and the other remains in unchallenged supremacy on the mental field. As soon, for example, as consciousness is accepted as a form of energy, the conflict with the doctrine of conservation disappears and the psychologist becomes an interactionist. If the difference between conscious states and energy is emphasized, and the differences between the relation of the mental and the physical and the causal relation in the purely physical realm increase in prominence, the man refuses belief in interaction, and either remains in doubt or becomes a parallelist, which is probably essentially the same outcome.

Again, one may believe in socialism if one considers the evident disparity between the rewards of different individuals who may be regarded as of the same ability or as of the same degree of desert. One is firmly opposed to socialism when men are regarded as essentially very different in ability, and ability and desert are identified, or it is assumed that men differ in their deserts as completely as they do in ability. Just so long as the two sets of experiences fluctuate before the mind, one will be in doubt as to which of the abstract principles is the more desirable. When one persists, it is by that very fact believed. On a subject that depends upon knowledge, belief cannot be permanent. As long as there is no scientific knowledge about the extent of individual variation in ability, or general agreement about the relation between ability and desert, every man will have his socialistic moments and his individualistic moments, according as life has presented one feature or another to him in his immediate past. And individuals will be predominantly individualistic or socialistic as life as a whole has presented the advantages or the disadvantages of the present individualistic society. This presentation may have been in matters of practice or it may have been in matters of theory. In any case, we have belief in one theory or the other just so long as one set of experiences predominates in consciousness; doubt enters whenever there is rivalry between two sets of experience or alternating dominance of one and the other. Any similar instance of doubt or belief seems to 4 39 reduce to the same factors. Here again we may say that disbelief is no third state. When belief is lost in one statement, belief in something else or doubt ensues.

If we turn from the particular to the general, belief may be said to arise when any statement or interpretation harmonizes with experience as a whole, with the knowledge of the individual. We must, that is, go beyond the selfconsistency of the statement or object to its consistency with the wider whole. There is nothing particularly indefinite or mysterious about this statement if one will but accept the conclusion of modern psychology that no experience ever stands alone, but that even the apparently most simple mental operation really expresses large parts of earlier experience. In the simple perception, for example, we have the action of a vast number of facts acquired days and years before. No apparently discrete element is really discrete, but is the focusing point of consciousness as a whole. Every impression that enters consciousness does so by the positive or permissive action of forces derived from much of past experience. It follows then that to assert that belief depends upon very much of our earlier experience, in fact upon all that is active at the moment, does not require any new complication of the mechanism of mind. All that is necessary is to assume that the same factors that control attention or that direct the course of associations or constitute the attitude toward the interpretation of the entering impression in perception, are also the factors that pass upon the truth or the falsity of the resulting object or assertion. Since experiential factors are present and in active control there is no reason why they should not also be called upon to determine whether the product of their action is to be accepted or rejected. The operation of passing upon the product of a mental operation is part of the process of producing it. One usually takes place at the same time as the other and is always a result of the same kind of force. It is true, the product may linger in memory for a moment, to be tested after it has been formed. During this period forces or factors that were not operative before may enter to take part in the testing process and, if the new product fails to square with them as well as with those earlier effective, it will be rejected. It is difficult to say what limits of age may be put upon the experiences that play a part in the operation of testing. Certain it is that many very remote elements may have their part in it. Eemnants of knowledge or of habit acquired in early childhood may at times have their effect upon belief, and it is difficult to draw a definite line in time and to say that all earlier experiences were without influence, all later ones were effective.

Not all experience is organized into perfectly consistent systems. As a result we find that not all of experience, or even all that is essential, need be active at any one moment in the testing. In consequence, as different systems come into prominence successively, the attitude toward the construct will vary and with this variation the interpretation fluctuates and the consequent doubt supervenes. This gives the change in mental attitude. Doubt is due to the alternating dominance of systems of experience that have not been altogether coordinated one with another. In this as in many other connections it is seen that this attitude or purpose varies from moment to moment. When two more or less opposed systems succeed one another closely, the whole train of alternating interpretations ensues and the unsteadiness results in alternating beliefs. These characterize the doubt consciousness. In some matters and at some moments one context and one alone is present. That constitutes or characterizes the momentarily settled conviction. In other matters several systems or contexts conflict and no single organization can be made to include them all. Conviction is lacking or unsettled and, unless settled, some shadowing of the disturbance gives rise to the general experience of doubt.

This dependence of belief upon earlier experiences and upon the reaction of earlier acquired knowledge upon the momentary product is evidenced by a consideration, in the individual or in the race, of the change in beliefs with growth in knowledge. Some evidence can also be obtained for it from a study of the conditions of partial and temporary beliefs and of other somewhat pathological or unusual forms. The slightest observation shows that growth in knowledge is invariably accompanied by corresponding change in belief. The man of the early historic periods accepted any statement not in direct conflict with his experience. He peopled the universe with fairies and super-human beings, with witches and weir-wolves; he put implicit confidence in absurd cures for disease and in spells and incantations. It is only as man has grown in knowledge, and experiences have become sufficiently numerous and may be treated with sufficient discrimination to make evident the conflict of the new with the old, that doubt is at all possible. Similarly if we trace the development of accepted theory in any branch of science we find that the theories of any period harmonize with the observation and accumulated knowledge of the period. These theories are changed only as new facts and observations appear. So the explanation of perception and all action at a distance by corpuscular emanations was held to as long as there were no facts in direct opposition. As facts accumulated that would not fit into the theoretical scheme, people began to doubt it.

It was abandoned in one field after another as the facts that would not fit became numerous enough to overwhelm it, and a new coordination was hit upon that would be less in conflict with the observations. It is interesting to note that the senses that have been most useful or could be most easily investigated were the first to accept the explanation in terms of wave motion. In the individual, too, we find, as experiences accumulate, the same increase in the severity of the tests that are applied. Children accept with relatively little question anything that their senses give them, or that anyone tells them. The phrase childlike credulity is an accurate indication of the facts. As they grow older or as knowledge accumulates they become more and more difficult to satisfy. Their credulity disappears with increasing age and intelligence. Fewer and fewer general statements will be believed because fewer are in harmony with their knowledge. Their beliefs become at once more restricted and more trustworthy when tested by the generally accepted standards. The individual of restricted experience shares with the child ready belief and restricted doubt. Illustrations of both of these statements will undoubtedly be suggested to all without further illustration. Both lines of evolution tend to confirm our general thesis that belief is an immediate and complete expression of the earlier acquired knowledge of the individual so far as he has it ready to pass upon the new experiences and statements which present themselves.