CHAPTER II.

METHOD OF PSYCHOLOGY.

Psychology a Science. -- In describing Psychology as the science of the human mind or soul, three conditions are implied -- first, that Psychology has a definite subject-matter, the nature and activities of the thinking subject; secondly, that it possesses an efficient method; thirdly, that it comprehends a systematized body of general truths, or, in other words, that it embraces a number of facts in their relations to their universal causes. In our first hapter we sought to mark out clearly the field of our science; in the present we propose to describe its method, pointing out the chief instruments of investigation which lie open to us; the rest of the work will be devoted to the satisfaction of the third essential requirement.

The Subjective or Introspective Method. -- The subject-matter of Empirical Psychology is consciousness. Now states of consciousness can only be observed by introspection -- that is, by the turning of the mind in on itself. Consequently this faculty of internal observation must be our chief instrument in the study of the mind. To its adjudication must be the first as well as the ultimate appeal in every psychological problem. Mental states can only be apprehended by each man's own consciousness. Their reality consists in this apprehension -- their esse is percipi. Therefore the endeavour to decide as to their nature or origin by information gathered from any other source is obviously absurd. The greatest care must, however, be taken to notice accurately all the aspects of the phenomena presented to us, and to detect those numerous unobtrusive differences in the character of mental phenomena which may indicate profound divergency in the nature of their source. The injudicious observer, impressed by the greater intensity of sentient states, may thus easily ignore the more subtle activities of our higher rational life, and so be led to form a conception of mind from which the most important features are absent.^{1}

Still, although our mental states are of an evanescent character, and enjoy but a transitory existence, it must nevertheless be insisted on that they are facts as real as any in the universe. A sensation, an intellectual judgment, or a volition, possesses as much reality as a nervous current, a chemical solution, or a transit of Venus; and whilst the most thorough-going sceptic cannot question the existence of states of consciousness, ingenious and acute thinkers have been found over and over again to deny us all certainty regarding material objects. This mode of investigating psychical phenomena by means of internal observation is called the Subjective or Introspective Method.

Objective Method. -- Introspection must be supplemented, however, by other lines of research, if we wish to make our conclusions as trustworthy and as widely applicable as possible. Appeal to hese additional means of information constitutes what is called the Objective Method of inquiry, since they form part of the outside world, and are apprehended only through the external senses. But evidence gained in this way is of an essentially secondary or supplementary value, its chief use being that of suggestion or corroboration. The principal forms of objective investigation are the following:

1. Other minds. -- The results of other men's observations of their own minds as far as these results can be gathered from oral description, and compared with the results of our own individual experience.

2. Language. -- The products of the human mind embodied in language may afford valuable information. Comparative philology and the study of various literatures are here our chief resources. Language has been happily styled crystallized or fossilized thought, and under skilful handling it may be made to unfold many interesting secrets of past mental history. Thus the rich and varied vocabulary of the Tagan dialect, which contains over 30,000 words, a vast inherited wealth far beyond the needs of the present generation, is maintained by Professor Max Müller to point to a degradation of that race from a previous condition of considerable mental development, rather than to a gradual evolution from a lower and less intellectual state.^{2} Similarly the presence in various languages of words connoting certain moral ideas may constitute important testimony in disputed interpretations of consciousness.

3. Historical or Genetic Method. -- A diligent study of the human mind as manifested at different periods of life, and in different grades of civilization, may throw much light on the laws which govern the development of the mental faculties, and on the conditions which have given rise to various customs, sentiments, and modes of thought. Historical researches into the manners, religions, and social institutions of different nations may here prove very fruitful.

4. Animal Psychology. -- The study of the instincts, habits, and other psychical activities of the lower animals, if undertaken in a sober and judicious spirit, can be made to yield considerable assistance in some questions. This sphere of investigation, when grouped with that just mentioned, is sometimes rather questionably dignified with the title of Comparattve Psychology. However, the anthropomorphic tendency in man to project his own thoughts and sentiments into other beings renders this scientific instrument peculiarly liable to abuse. Still subject to proper precautions it may assist us materially. By means of it we may advantageously apply the great inductive methods of difference and residues. The lower animals possess certain faculties in common with man, but they are deficient in others, and hence by a diligent study of their actions we are enabled to distinguish how much of man's conduct is necessarily due to different faculties.

5. Physiology. -- The science of Physiology is also valuable information. The intimate nature of the relations between the mind and the organism, so strongly emphasized in the Aristotelian and Scholastic Philosophy which conceives the soul as the form of the body, receives more elucidation every day with the advance of biological science. In examining into the operations of sense, the development of imagination and memory, the formation of habits, and the transmission of hereditary tendencies, the advantage of a knowledge of the physical basis of these phenomena is obvious; but as all mental processes, even the most purely spiritual acts of intellect and volition, are probably accompanied or conditioned by cerebral changes, too much labour cannot be devoted to the study of the constitution, structure, and working of the organism. At the same time care must be taken to distinguish clearly between the two orders of facts. The mental state and its physiological accompaniment or condition are separated, as Professor Tyndall says, by an "impassable chasm." It is then not sufficient to explicitly admit once or twice, as most writers of the Sensist school do admit, that the neural and psychical events are divided by a difference which transcends all other differences, and then to forget, or lead the reader to forget, the vital character of this difference. The mental states must be treated and described throughout in such a way that no confusion between the two kinds of phenomena is caused to arise in the student's mind, and he must not be misled into supposing that a conscious process has been finally explained when its physical correlate has been indicated, or when the whole operation has been described in cloudy physiological language.

6. Pathology: Psychiatry. -- Hand in hand with Physiology goes Pathology, the complementary science of organic disease; and the opportunities presented in the investigations connected with this branch of knowledge for the observation of mental activities in an isolated or abnormal condition will occasionally throw light on obscure questions. Somnambulism, illusions, hallucinations, and various forms of insanity exhibit particular mental functions under exceptional conditions, and not infrequently suggest or confirm explanations of special mental operations. Similarly, the study of those deprived of different senses may advance the scientific analysis of normal perception and the discovery of how much is due to the various faculties. But here again judgment is required, and we must be on our guard against assigning too much weight to irregular and exceptional cases. The emotional interest excited by abnormal occurrences may easily lead us to exaggerate their philosophical importance, and to Forget that after all the proper subject-matter of our ;cience is the mens sana in corpore sano. The reality if this danger becomes apparent when we find vriters on Psychology founding their theories as to the nature of the soul, or of its cognitive operations, not on the observation of the activities of the normal healthy mind, but on dubious conjectures regarding some obscure ill-understood forms of mental aberration that appear perhaps once among a hundred thousand human beings.

7. Experimental Psychology: Psycho-physics: Psychometry. -- Closely connected with physiological psychology are certain methods of investigation somemes styled Experimental Psychology. Strictly speaking, whenever we deliberately exert or cause another to exert any form of mental activity in order observe it we perform "a psychological experiment." But the term Experimental Psychology is commonly confined to the more elaborate methods modifying mental operations in order to study them. Various ingenious means have been recently invented for estimating the power and accuracy of imagination, memory, and the several senses; and numerous "psychological laboratories" have been erected for carrying on these investigations in Germany, America, and elsewhere. The terms psychometry and psycho-physics are more especially employed to denote sundry methods employed for measuring the duration of simple mental processes and also the relation between the intensity of sensations and their stimuli. We shall return to this subject again.

These Methods not new. -- We have here explicitly enumerated the various sources from which our science draws its materials, but, although it has only in recent times become customary thus to classify them in detail, all of them except the last have been made use of by writers on the philosophy of the mind since the days of Plato and Aristotle. Some recent authors appear at times to believe that these methods of inductive inquiry are a result of modern discovery, and that surprising advances of an undefined character have been, or in the immediate future will be, effected by their means in our knowledge of the nature of the mind. A comparatively brief study, however, of Aristotle's great work on the soul, and of his supplementary treatises on special psychological questions, will show how fully he appreciated the value of these extended fields of information.^{3}

Rational Psychology : Method. -- The method pursued in Rational Psychology will be mainly inferential. From the truths established in the earlier part of our work as regards the life of the soul, we shall draw inferences as to its inner constitution; from the character of the activity we shall argue to the nature of the agent, from the degree of perfection in the effect we shall reason up to that of the cause.

Attacks on Psychology. -- The scope just assigned to Psychology is objected to by writers of widely different schools in this country, so it may be well to add a few supplementary remarks in defence of our position. Opponents we may divide into three classes. Some deny the possibility of a science either of Rational or Phenomenal Psychology. Others, admitting the existence of a genuine science of the phenomena of the mind, deny the possibility of any real knowledge regarding the nature or existence of the soul. Others, again, whilst allowing with this second class the value of Empirical Psychology, exclude from its treatment various questions, such as the freedom of the will, and the origin of intellectual ideas, on the ground that these are metaphysical or philosophical problems to be treated of elsewhere. As regards this last view, the divergence from us may be mainly one of method and classification. Provided these questions are satisfactorily discussed in some branch of Philosophy, it does not appear vital what department be selected. We may, however, point out that Psychology, the philosophy of the mind, seems to be under more distinct obligations to face these problems than any other science; and, in the second place, as we have already stated, any attempt at adequate treatment of mental phenomena will inevitably involve some particular philosophical view as to the nature of our faculties.

The only sufficient answer to writers of the second class -- those who deny the possibility of a rational science of the soul -- is to work out a systematized body of certain truths regarding its nature, and the relations subsisting between it and the body. This we will endeavour to accomplish in the Second Book of the present volume. That a work claiming to be a treatise on Psychology ought to make some such attempt seems so manifest that it is difficult to understand why the duty should be so uniformly ignored in English manuals. Locke's influence and the national distaste for metaphysical argument has had much to do with it, but probably the authority of the Scotch school has had still more. For it was to Reid and Stewart those most interested in a satisfactory exposition of the evidence bearing on the existence and character of the human soul naturally looked for a proper vindication of the subject. Unfortunately, idolatry of empirical fact and contempt for deductive reasoning reached a climax in the common-sense school. As a consequence, the worship of the Baconian method in its most exaggeratedly vicious form wrought that evil in the science of the mind which it would assuredly have effected, had it been as faithfully followed, in the study of external nature.^{4} Thus we find that whilst in Germany and other Continental countries mental philosophy was approached with a view to the solution of the most interesting and important problems that can occupy the human spirit, British psychologists have been seeking to convert their science into a mere natural history of psychical phenomena. Any attempt at a comprehensive treatment of our mental activities is stigmatized as an illegitimate introduction of philosophical problems, and we have finally reached a stage in which even such a clearly psychological question as the freedom of the will is to be rigidly boycotted on the grounds of its connexion with the discredited science of metaphysics.

Objections to Introspection. -- As regards the third class of opponents -- those who deny the possibility of a genuine science even of phenomenal psychology -- since they attack the foundations on which our whole work rests, we will here state and answer briefly their chief arguments. The leading representatives of this view have been Comte in France, and Dr. Maudsley at home. Both teach that Psychology is merely a subsidiary department of Biology, and that it must be studied exclusively or mainly by objective methods. Dr. Maudsley states the case against Psychology at length in the earlier part of his work, The Physiology of Mind. But in this, as indeed in other philosophical questions, that vigorous writer does not appear to hold very clear or consistent opinions even throughout the course of the same volume.

1. He urges that Psychology, as a distinct independent science built up by introspection is impossible, for introspection is itself impossible "In order to observe its own action it is necessary that the mind pause from activity yet it is the train of activity that is to be observed." (The Physiology of Mind, p. 17.)

This assertion we dispute, and in support of our view we would appeal to each man's inner experience. First, as regards the various modes of our sentient life, sensations, perceptions, appetites, pleasures, and pains, our only difficulty is to understand how such a statement as that attention to them causes their immediate annihilation could ever have been penned. Life could be made happy without much difficulty if our disagreeable states and experiences would vanish when we turned observe them; but unfortunately cold, hunger, thirst, disease, the pains of muscular strain, and of tooth-ache are not such obliging visitors. The activities of sight, hearing, taste, smell, and touch, can certainly be studied both in actual operation on their objects, and as reproduced in imagination. Secondly, that we can attend to and examine our higher forms of mental activity is equally certain. Emotions, desires, perceptions of relations, reasonings can be both concomitantly studied in their direct course^{5} and afterwards recalled by memory. This is due equally in either case to the self-conscious power of the mind, and implies in us a higher order of mental activity than that involved in mere sentient affections. Our only proof of this, as well as of every other psychological fact, must be an appeal to each man's own consciousness.

2. Again, it is a maxim of "inductive philosophy that observation should begin with simple instances, ascent being made from them step by step through appropriate generalizations" (Maudsley, p. 19.) Moreover, science being universal, the psychologist should be able to contemplate a variety of specimens which exhibit the object of his investigations in its various stages of development. But introspection presents only a single subject for examination, and that a most rare and exceptional one, "the complex self-consciousness of an educated white man." Consequently, even were introspection possible, its deliverances would be deprived of that feature of universality essential to every genuine science. To this we may reply in the first place that, were a number of anatomists limited each to the study of a single human organism, they would still be able to frame a collection of results containing a substantial amount of agreement. Secondly, comparison of observations among psychologists, appeal to general experience, and the several objective methods we have described, and which have been in use from the very birth of Psychology, completely destroy the force of the supposed difficulty.

3. A kindred objection is urged against the necessary limitation of introspective observation, to a single observer, "a witness whose evidence can be taken by no one but himself, and whose veracity, therefore, cannot be tested. . . . The observed and the observer are one, and the observer is not likely in such a case to be unbiassed by the feelings of the observed, and to conform rigidly to the rules of exact observation." (id.) The answer to the last objection will apply again in great part here. Further, (a) the psychologist, like the physiologist and every other scientific inquirer, must seek to lay aside prejudice and to approach his subject in an impartial spirit. (b) He must, like them, exercise care and diligence. And (c) he must check his results by comparison with those of other observers, and by the study of other minds through the various supplementary methods.

4. Dr. Maudsley also argues that the range of introspection is very limited. (a) "Consciousness which does not even tell us that we have a brain is certainly incompetent to give any account of the essential material conditions of our mental life." (p. 21.) (b) Mental life itself, too, is largely beyond the range of introspection. "It is a truth which cannot too distinctly be borne in mind, that consciousness is not co-extensive with mind." (p. 25.) As regards the first part of the difficulty it might, perhaps, be not unfairly retorted against the physiologist that the method of external observation on which his science is based can tell us nothing of the mental conditions which profoundly influence many physical processes. Letting this pass, however, it is sufficient to recall to mind that conscious states and mental activities are real facts differing in kind from all physical events, in order to give them as good claim to form adequate matter for an independent science as physiology has to be separated from chemistry or mechanics. Finally, that the study of the physical conditions of conscious processes is a legitimate source of useful supplementary information has been, as we before urged, fully admitted from the time of Aristotle; but unfortunately, owing to the hitherto extremely backward condition of the science of Physiology in general, and especially in that department which deals with physical basis of mental life, it can afford very little reliable information of any importance.

5. Dr. Maudsley also argues that the illusions and hallucinations of the insane seem to them as clear and evident affirmations of consciousness, as do the introspective observations of the psychologist. Therefore the latter are untrustworthy. This objection is trivial. Insanity is, unhappily, a possible contingency among the investigators both of soul and body, but science will not be ultimately injured by such casualties.

6. Finally, it is urged, as a general proof of the worthlessness of Subjective Psychology, that "there is no agreement between those who have acquired the power of introspection." (id.) This objection is based on a confusion of two very distinct questions -- the character of the mental states of which psychologists affirm that they are conscious, and the hypotheses or explanations which they advance to account for these states. As regards the former, that there is a very large amount of general agreement, any one who consults the psychological literature even of schools the most opposed will discover. On the other hand, wide and manifold divergence in the theories advanced to explain the origin and nature of mental life, the history of Philosophy since the great scholastic stream of thought was abandoned unequivocally demonstrates. But that is not the fault of introspection any more than conflicting views as to the source of the sun's heat are a reflection on the trustworthiness of the telescope.

Real Difficulties. -- We have treated Dr. Maudsley's objections at such great length, not on account of any considerable importance we assign to his work, but because the discussion of his arguments helps to make clear to the student the actual difficulties and limitations of the Introspective Method. For it must be admitted that internal observation is often not easy. Mental states, unlike the objects of physical science, are unstable and ever changing. They are not independent of concomitant states. Even though it be untrue that all introspection must be retrospective, yet the more vehement forms of mental excitement can be adequately studied only by means of recollection. The imitation, too, of direct observation to a single specimen with its inevitable peculiarities may be attended by serious risks. Bias and intellectual prejudices may unconsciously interfere with the correct appreciation of facts, and our very familiarity with our mental states increases the labour of accurate observation. Still these hindrances to introspection can be overcome by (a) diligence and attention, (b) the skill acquired by practice of reflection, (c) industry in repeating our observations under varied conditions and the employment of recollection in studying afterwards states which cannot be well examined whilst actually occurring, (d) honest effort to be unprejudiced and impartial in the observation of facts and to be on our guard against the more impressive features of imagination and sensuous states; finally, by (e) making the fullest use of the various supplementary objective methods to test and confirm the results of direct introspection.

Readings. -- On the opposition in nature between Psychology and objective sciences, cf. Dr. Martineau's Essays Philosophical and Theogical, "Cerebral Psychology," pp. 245-253. On the various methods, cf. Pesch, Institutiones Psych. §§ 25-30; Dr. Gutberlet, Die Psychologie (Munster) pp. 1-15; and F. Mark Baldwin, Sense and Intellect, pp. 20-32. On objections to the possibility of Psychology, cf. Pesch, ib. §§ 31-34. On the necessity of a consistent theory of Rational Psychology, even for a complete view of the physiological conditions of mental activity, cf. Professor Ladd's Physiological Psychology, pp. 585, 586; see also "Mind" and "Psychology," by the Author in the Catholic Encyclopedia.

{1} The truth of this remark is strikingly illustrated in the history of Mental Philosophy in this country by the manner in which the relational activity of the mind -- its power of apprehending universal relations -- has been ignored or misconceived by the entire sensationalist school from Hartley to Dr. Bain. The writings of Stirling, Green, Bradley, and other thinkers of Hegelian tendencies have had in recent years the good effect of bringing about the re-discovery of this intellectual faculty, which occupied such a prominent position in the psychological system of the leading scholastic philosophers.

{2} Cf. "The Savage," Nineteenth Century, January, 2885, p. 120. Professor Max Müller there argues very forcibly, that "the magnificent ruins in the dialects, whether of Fuegians, Mohawks, or Hottentots, tell us of mental builders whom no one could match at present." The Tagan language is that spoken by the natives of Terra del Fuego, the race which Darwin considered to be the lowest and least developed family of human beings yet found.

{3} M. St. Hilaire has shown clearly how accurate were the views of the founder of the Peripatetic school on the use of the inductive methods in Psychology. (Cf. Psychologie d'Aristote, pp. lii. -- lxv.)

{4} On the reaction against the pure Baconian doctrine of method in recent times, see Jevons' Principles of Science, Vol. II. c. xxiii. He remarks that "its value may he estimated historically by the fact that it has not been followed hy any of the great masters of science." (p. 134.)

{5} Mr. Sully, who defends the introspective method, yet seems to that immediate concomitant consideration of present mental states is impossible, that it is only last states we can properly be said to observe, and that in fact "all introspection is retrospection" Illusions, p. 190, and Outlines of Psychology, p. 5.) This tenet is a necessary deduction from the sensationist theory of mental life, but the logical position for the disciple of that school is that assumed by Dr. Maudsley, and not the halting inconsistent doctrine of Mr. Sully. To the mind endowed with no activity essentially higher than that of the sensuous order, both introspection and introspection are equally impossible. But that the human mind is capable of concomitantly observing its own normal states becomes clear to any one making the attempt. It is actually the converse of Mr. Sully's dictum which expresses the truth, "All retrospection involves present introspection," for, it is the Present representation of the past state which is examined, and only while actually present to the mind can it be the subject of observation. But if we can attend to a present state which happens to be an image of a past state, surely there can be nothing to prevent attention to a state which is not such a representation. Consequently we can concomitantly study those mental processes of which we are conscious. In a word, as Mill urges against Comte, "Whatever we are directly aware of we can directly observe." (Auguste Comte and Positivism, p. 64.)