[960] Ever since the early days of science, it has been a notable endeavour of the reflective intellect to interpose gradations between the two poles of the absolute similarity and dissimilarity of human beings. This resulted in a number of types, or “temperaments” as they were then called, which classified similarities and dissimilarities into regular categories. The Greek philosopher Empedocles attempted to impose order on the chaos of natural phenomena by dividing them into the four elements: earth, water, air, and fire. It was above all the physicians of ancient times who applied this principle of order, in conjunction with the related doctrine of the four qualities, dry, moist, cold, warm, to human beings, and thus tried to reduce the bewildering diversity of mankind to orderly groups. Of these physicians one of the most important was Galen, whose use of these teachings influenced medical science and the treatment of the sick for nearly seventeen hundred years. The very names of the Galenic temperaments betray their origin in the pathology of the four “humours.” Melancholic denotes a preponderance of black bile, phlegmatic a preponderance of phlegm or mucus (the Greek word phlegma means fire, and phlegm was regarded as the end-product of inflammation), sanguine a preponderance of blood, and choleric a preponderance of choler, or yellow bile.
[961] Our modern conception of “temperament” has certainly become much more psychological, since in the course of man’s development over the last two thousand years the “soul” has freed itself from any conceivable connection with cold agues and fevers, or secretions of mucus and bile. Not even the doctors of today would equate a temperament, that is, a certain kind of emotional state or excitability, directly with the constitution of the blood or lymph, although their profession and their exclusive approach to human beings from the side of physical illness tempt them, more often than the layman, to regard the psyche as an end-product dependent on the physiology of the glands. The “humours” of present-day medicine are no longer the old body-secretions, but the more subtle hormones, which influence “temperament” to an outstanding degree, if we define this as the sum-total of emotional reactions. The whole make-up of the body, its constitution in the broadest sense, has in fact a very great deal to do with the psychological temperament, so much that we cannot blame the doctors if they regard psychic phenomena as largely dependent on the body. Somewhere the psyche is living body, and the living body is animated matter; somehow and somewhere there is an undiscoverable unity of psyche and body which would need investigating psychically as well as physically; in other words, this unity must be as dependent on the body as it is on the psyche so far as the investigator is concerned. The materialism of the nineteenth century gave the body first place and relegated the psyche to the rank of something secondary and derived, allowing it no more substantiality than that of a so-called “epiphenomenon.” What proved to be a good working hypothesis, namely, that psychic phenomena are conditioned by physical processes, became a philosophical presumption with the advent of materialism. Any serious science of the living organism will reject this presumption; for on the one hand it will constantly bear in mind that living matter is an as yet unsolved mystery, and on the other hand it will be objective enough to recognize that for us there is a completely unbridgeable gulf between physical and psychic phenomena, so that the psychic realm is no less mysterious than the physical.
[962] The materialistic presumption became possible only in recent times, after man’s conception of the psyche had, in the course of many centuries, emancipated itself from the old view and developed in an increasingly abstract direction. The ancients could still see body and psyche together, as an undivided unity, because they were closer to that primitive world where no moral rift yet ran through the personality, and the pagan could still feel himself indivisibly one, childishly innocent and unburdened by responsibility. The ancient Egyptians could still enjoy the naïve luxury of a negative confession of sin: “I have not let any man go hungry. I have not made anyone weep. I have not committed murder,” and so on. The Homeric heroes wept, laughed, raged, outwitted and killed each other in a world where these things were taken as natural and self-evident by men and gods alike, and the Olympians amused themselves by passing their days in a state of amaranthine irresponsibility.
[963] It was on this archaic level that pre-philosophical man lived and experienced the world. He was entirely in the grip of his emotions. All passions that made his blood boil and his heart pound, that accelerated his breathing or took his breath away, that “turned his bowels to water”—all this was a manifestation of the “soul.” Therefore he localized the soul in the region of the diaphragm (in Greek phren, which also means mind)2 and the heart. It was only with the first philosophers that the seat of reason began to be assigned to the head. There are still Negroes today whose “thoughts” are localized principally in the belly, and the Pueblo Indians “think” with their hearts—“only madmen think with their heads,” they say.3 On this level consciousness is essentially passion and the experience of oneness. Yet, serene and tragic at once, it was just this archaic man who, having started to think, invented that dichotomy which Nietzsche laid at the door of Zarathustra: the discovery of pairs of opposites, the division into odd and even, above and below, good and evil. It was the work of the old Pythagoreans, and it was their doctrine of moral responsibility and the grave metaphysical consequences of sin that gradually, in the course of the centuries, percolated through to all strata of the population, chiefly owing to the spread of the Orphic and Pythagorean mysteries. Plato even used the parable of the white and black horses4 to illustrate the intractability and polarity of the human psyche, and, still earlier, the mysteries proclaimed the doctrine of the good rewarded in the Hereafter and of the wicked punished in hell. These teachings cannot be dismissed as the mystical humbug of “backwoods” philosophers, as Nietzsche claimed, or as so much sectarian cant, for already in the sixth century B.C. Pythagoreanism was something like a state religion throughout Graecia Magna. Also, the ideas underlying its mysteries never died out, but underwent a philosophical renaissance in the second century B.C., when they exercised the strongest influence on the Alexandrian world of thought. Their collision with Old Testament prophecy then led to what one can call the beginnings of Christianity as a world religion.
[964] From Hellenistic syncretism there now arose a classification of man into types which was entirely alien to the “humoral” psychology of Greek medicine. In the philosophical sense, it established gradations between the Parmenidean poles of light and darkness, of above and below. It classified men into hylikoi, psychikoi, and pneumatikoi—material, psychic, and spiritual beings. This classification is not, of course, a scientific formulation of similarities and dissimilarities; it is a critical system of values based not on the behaviour and outward appearance of man as a phenotype, but on definitions of an ethical, mystical, and philosophic kind. Although it is not exactly a “Christian” conception it nevertheless forms an integral part of early Christianity at the time of St. Paul. Its very existence is incontrovertible proof of the split that had occurred in the original unity of man as a being entirely in the grip of his emotions. Before this, he was merely alive and there, the plaything of experience, incapable of any reflective analysis concerning his origins and his destination. Now, suddenly, he found himself confronted by three fateful factors and endowed with body, soul, and spirit, to each of which he had moral obligations. Presumably it was already decided at birth whether he would pass his life in the hylic or the pneumatic state, or in the indeterminate centre between the two. The ingrained dichotomy of the Greek mind had now become acute, with the result that the accent shifted significantly to the psychic and spiritual, which was unavoidably split off from the hylic realm of the body. All the highest and ultimate goals lay in man’s moral destination, in a spiritual, supramundane end-state, and the separation of the hylic realm broadened into a cleavage between world and spirit. Thus the original, suave wisdom expressed in the Pythagorean pairs of opposites became a passionate moral conflict. Nothing, however, is so apt to challenge our self-awareness and alertness as being at war with oneself. One can hardly think of any other or more effective means of waking humanity out of the irresponsible and innocent half-sleep of the primitive mentality and bringing it to a state of conscious responsibility.
[965] This process is called cultural development. It is, at any rate, a development of man’s powers of discrimination and capacity for judgment, and of consciousness in general. With the increase of knowledge and enhanced critical faculties the foundations were laid for the whole subsequent development of the human mind in terms of intellectual achievement. The particular mental product that far surpassed all the achievements of the ancient world was science. It closed the rift between man and nature in the sense that, although he was separated from nature, science enabled him to find his rightful place again in the natural order. His special metaphysical position, however, had to be jettisoned—so far as it was not secured by belief in the traditional religion—whence arose the notorious conflict between “faith and knowledge.” At all events, science brought about a splendid rehabilitation of matter, and in this respect materialism may even be regarded as an act of historical justice.
[966] But one absolutely essential field of experience, the human psyche itself, remained for a very long time the preserve of metaphysics, although increasingly serious attempts were made after the Enlightment to open it up to scientific investigation. They began, tentatively, with the sense perceptions, and gradually ventured into the domain of associations. This line of research paved the way for experimental psychology, and it culminated in the “physiological psychology” of Wundt. A more descriptive kind of psychology, with which the medical men soon made contact, developed in France. Its chief exponents were Taine, Ribot, and Janet. It was characteristic of this scientific approach that it broke down the psyche into particular mechanisms or processes. In face of these attempts, there were some who advocated what we today would call a “holistic” approach—the systematic observation of the psyche as a whole. It seems as if this trend originated in a certain type of biography, more particularly the kind that an earlier age, which also had its good points, used to describe as “curious lives.” In this connection I think of Justinus Kerner and his Seeress of Prevorst, and the case of the elder Blumhardt and his medium Gottliebin Dittus.5 To be historically fair, however, I should not forget the medieval Acta Sanctorum.6
[967] This line of research has been continued in more recent investigations associated with the names of William James, Freud, and Theodore Flournoy. James and his friend Flournoy, a Swiss psychologist, made an attempt to describe the whole phenomenology of the psyche and also to view it as a totality. Freud, too, as a doctor, took as his point of departure the wholeness and indivisibility of the human personality, though, in keeping with the spirit of the age, he restricted himself to the investigation of instinctive mechanisms and individual processes. He also narrowed the picture of man to the wholeness of an essentially “bourgeois” collective person, and this necessarily led to philosophically onesided interpretations. Freud, unfortunately, succumbed to the medical man’s temptation to trace everything psychic to the body, in the manner of the old “humoral” psychologists, not without rebellious gestures at those metaphysical preserves of which he had a holy dread.
[968] Unlike Freud, who after a proper psychological start reverted to the ancient assumption of the sovereignty of the physical constitution, trying to turn everything back in theory into instinctual processes conditioned by the body, I start with the assumption of the sovereignty of the psyche. Since body and psyche somewhere form a unity, although in their manifest natures they are so utterly different, we cannot but attribute to the one as to the other a substantiality of its own. So long as we have no way of knowing that unity, there is no alternative but to investigate them separately and, for the present, treat them as though they were independent of each other, at least in their structure. That they are not so, we can see for ourselves every day. But if we were to stop at that, we would never be in a position to make out anything about the psyche at all.
[969] Now if we assume the sovereignty of the psyche, we exempt ourselves from the—at present—insoluble task of reducing everything psychic to something definitely physical. We can then take the manifestations of the psyche as expressions of its intrinsic being, and try to establish certain conformities or types. So when I speak of a psychological typology, I mean by this the formulation of the structural elements of the psyche and not a description of the psychic emanations of a particular type of constitution. This is covered by, for instance, Kretschmer’s researches into body-structure and character.
[970] I have given a detailed description of a purely psychological typology in my book Psychological Types. My investigation was based on twenty years of work as a doctor, which brought me into contact with people of all classes from all the great nations. When one begins as a young doctor, one’s head is still full of clinical pictures and diagnoses. In the course of the years, impressions of quite another kind accumulate. One is struck by the enormous diversity of human individuals, by the chaotic profusion of individual cases, the special circumstances of whose lives and whose special characters produce clinical pictures that, even supposing one still felt any desire to do so, can be squeezed into the straitjacket of a diagnosis only by force. The fact that the disturbance can be given such and such a name appears completely irrelevant beside the overwhelming impression one has that all clinical pictures are so many mimetic or histrionic demonstrations of certain definite character traits. The pathological problem upon which everything turns has virtually nothing to do with the clinical picture, but is essentially an expression of character. Even the complexes, the “nuclear elements” of a neurosis, are beside the point, being mere concomitants of a certain characterological disposition. This can be seen most easily in the relation of the patient to his parental family. He is, let us say, one of four siblings, is neither the eldest nor the youngest, has had the same education and conditioning as the others. Yet he is sick and they are sound. The anamnesis shows that a whole series of influences to which the others were exposed as well as he, and from which indeed they all suffered, had a pathological effect on him alone—at least to all appearances. In reality these influences were not aetiological factors in his case either, but prove to be false explanations. The real cause of the neurosis lies in the peculiar way he responded to and assimilated the influences emanating from the environment.
[971] By comparing many such cases it gradually became clear to me that there must be two fundamentally different general attitudes which would divide human beings into two groups—provided the whole of humanity consisted of highly differentiated individuals. Since this is obviously not the case, one can only say that this difference of attitude becomes plainly observable only when we are confronted with a comparatively well-differentiated personality; in other words, it becomes of practical importance only after a certain degree of differentiation has been reached. Pathological cases of this kind are almost always people who deviate from the familial type and, in consequence, no longer find sufficient security in their inherited instinctual foundation. Weak instincts are one of the prime causes of the development of an habitual one-sided attitude, though in the last resort it is conditioned or reinforced by heredity.
[972] I have called these two fundamentally different attitudes extraversion and introversion. Extraversion is characterized by interest in the external object, responsiveness, and a ready acceptance of external happenings, a desire to influence and be influenced by events, a need to join in and get “with it,” the capacity to endure bustle and noise of every kind, and actually find them enjoyable, constant attention to the surrounding world, the cultivation of friends and acquaintances, none too carefully selected, and finally by the great importance attached to the figure one cuts, and hence by a strong tendency to make a show of oneself. Accordingly, the extravert’s philosophy of life and his ethics are as a rule of a highly collective nature with a strong streak of altruism, and his conscience is in large measure dependent on public opinion. Moral misgivings arise mainly when “other people know.” His religious convictions are determined, so to speak, by majority vote.
[973] The actual subject, the extravert as a subjective entity, is, so far as possible, shrouded in darkness. He hides it from himself under veils of unconsciousness. The disinclination to submit his own motives to critical examination is very pronounced. He has no secrets he has not long since shared with others. Should something unmentionable nevertheless befall him, he prefers to forget it. Anything that might tarnish the parade of optimism and positivism is avoided. Whatever he thinks, intends, and does is displayed with conviction and warmth.
[974] The psychic life of this type of person is enacted, as it were, outside himself, in the environment. He lives in and through others; all self-communings give him the creeps. Dangers lurk there which are better drowned out by noise. If he should ever have a “complex,” he finds refuge in the social whirl and allows himself to be assured several times a day that everything is in order. Provided he is not too much of a busybody, too pushing, and too superficial, he can be a distinctly useful member of the community.
[975] In this short essay I have to content myself with an allusive sketch. It is intended merely to give the reader some idea of what extraversion is like, something he can bring into relationship with his own knowledge of human nature. I have purposely started with a description of extraversion because this attitude is familiar to everyone; the extravert not only lives in this attitude, but parades it before his fellows on principle. Moreover it accords with certain popular ideals and moral requirements.
[976] Introversion, on the other hand, being directed not to the object but to the subject, and not being oriented by the object, is not so easy to put into perspective. The introvert is not forthcoming, he is as though in continual retreat before the object. He holds aloof from external happenings, does not join in, has a distinct dislike of society as soon as he finds himself among too many people. In a large gathering he feels lonely and lost. The more crowded it is, the greater becomes his resistance. He is not in the least “with it,” and has no love of enthusiastic get-togethers. He is not a good mixer. What he does, he does in his own way, barricading himself against influences from outside. He is apt to appear awkward, often seeming inhibited, and it frequently happens that, by a certain brusqueness of manner, or by his glum unapproachability, or some kind of malapropism, he causes unwitting offence to people. His better qualities he keeps to himself, and generally does everything he can to dissemble them. He is easily mistrustful, self-willed, often suffers from inferiority feelings and for this reason is also envious. His apprehensiveness of the object is not due to fear, but to the fact that it seems to him negative, demanding, overpowering or even menacing. He therefore suspects all kinds of bad motives, has an everlasting fear of making a fool of himself, is usually very touchy and surrounds himself with a barbed wire entanglement so dense and impenetrable that finally he himself would rather do anything than sit behind it. He confronts the world with an elaborate defensive system compounded of scrupulosity, pedantry, frugality, cautiousness, painful conscientiousness, stiff-lipped rectitude, politeness, and open-eyed distrust. His picture of the world lacks rosy hues, as he is over-critical and finds a hair in every soup. Under normal conditions he is pessimistic and worried, because the world and human beings are not in the least good but crush him, so he never feels accepted and taken to their bosom. Yet he himself does not accept the world either, at any rate not outright, for everything has first to be judged by his own critical standards. Finally only those things are accepted which, for various subjective reasons, he can turn to his own account.
[977] For him self-communings are a pleasure. His own world is a safe harbour, a carefully tended and walled-in garden, closed to the public and hidden from prying eyes. His own company is the best. He feels at home in his world, where the only changes are made by himself. His best work is done with his own resources, on his own initiative, and in his own way. If ever he succeeds, after long and often wearisome struggles, in assimilating something alien to himself, he is capable of turning it to excellent account. Crowds, majority views, public opinion, popular enthusiasm never convince him of anything, but merely make him creep still deeper into his shell.
[978] His relations with other people become warm only when safety is guaranteed, and when he can lay aside his defensive distrust. All too often he cannot, and consequently the number of friends and acquaintances is very restricted. Thus the psychic life of this type is played out wholly within. Should any difficulties and conflicts arise in this inner world, all doors and windows are shut tight. The introvert shuts himself up with his complexes until he ends in complete isolation.
[979] In spite of these peculiarities the introvert is by no means a social loss. His retreat into himself is not a final renunciation of the world, but a search for quietude, where alone it is possible for him to make his contribution to the life of the community. This type of person is the victim of numerous misunderstandings—not unjustly, for he actually invites them. Nor can he be acquitted of the charge of taking a secret delight in mystification, and that being misunderstood gives him a certain satisfaction, since it reaffirms his pessimistic outlook. That being so, it is easy to see why he is accused of being cold, proud, obstinate, selfish, conceited, cranky, and what not, and why he is constantly admonished that devotion to the goals of society, clubbableness, imperturbable urbanity, and selfless trust in the powers-that-be are true virtues and the marks of a sound and vigorous life.
[980] The introvert is well enough aware that such virtues exist, and that somewhere, perhaps—only not in his circle of acquaintances—there are divinely inspired people who enjoy undiluted possession of these ideal qualities. But his self-criticism and his awareness of his own motives have long since disabused him of the illusion that he himself would be capable of such virtues; and his mistrustful gaze, sharpened by anxiety, constantly enables him to detect on his fellow men the ass’s ear sticking up from under the lion’s mane. The world and men are for him a disturbance and a danger, affording no valid standard by which he could ultimately orient himself. What alone is valid for him is his subjective world, which he sometimes believes, in moments of delusion, to be the objective one. We could easily charge these people with the worst kind of subjectivism, indeed with morbid individualism, if it were certain beyond a doubt that only one objective world existed. But this truth, if such it be, is not axiomatic; it is merely a half truth, the other half of which is the fact that the world also is as it is seen by human beings, and in the last resort by the individual. There is simply no world at all without the knowing subject. This, be it never so small and inconspicuous, is always the other pier supporting the bridge of the phenomenal world. The appeal to the subject therefore has the same validity as the appeal to the so-called objective world, for it is grounded on psychic reality itself. But this is a reality with its own peculiar laws which are not of a secondary nature.
[981] The two attitudes, extraversion and introversion, are opposing modes that make themselves felt not least in the history of human thought. The problems to which they give rise were very largely anticipated by Friedrich Schiller, and they underlie his Letters on the Aesthetic Education of Man.7 But since the concept of the unconscious was still unknown to him, he was unable to reach a satisfactory solution. Moreover philosophers, who would be the best equipped to go more closely into this question, do not like having to submit their thinking function to a thorough psychological criticism, and therefore hold aloof from such discussions. It should, however, be obvious that the intrinsic polarity of such an attitude exerts a very great influence on the philosopher’s own point of view.
[982] For the extravert the object is interesting and attractive a priori, as is the subject, or psychic reality, for the introvert. We could therefore use the expression “numinal accent” for this fact, by which I mean that for the extravert the quality of positive significance and value attaches primarily to the object, so that it plays the predominant, determining, and decisive role in all psychic processes from the start, just as the subject does for the introvert.
[983] But the numinal accent does not decide only between subject and object; it also selects the conscious function of which the individual makes the principal use. I distinguish four functions: thinking, feeling, sensation, and intuition. The essential function of sensation is to establish that something exists, thinking tells us what it means, feeling what its value is, and intuition surmises whence it comes and whither it goes. Sensation and intuition I call irrational functions, because they are both concerned simply with what happens and with actual or potential realities. Thinking and feeling, being discriminative functions, are rational. Sensation, the fonction du réel, rules out any simultaneous intuitive activity, since the latter is not concerned with the present but is rather a sixth sense for hidden possibilities, and therefore should not allow itself to be unduly influenced by existing reality. In the same way, thinking is opposed to feeling, because thinking should not be influenced or deflected from its purpose by feeling values, just as feeling is usually vitiated by too much reflection. The four functions therefore form, when arranged diagrammatically, a cross with a rational axis at right angles to an irrational axis.
[984] The four orienting functions naturally do not contain everything that is in the conscious psyche. Will and memory, for instance, are not included. The reason for this is that the differentiation of the four orienting functions is, essentially, an empirical consequence of typical differences in the functional attitude. There are people for whom the numinal accent falls on sensation, on the perception of actualities, and elevates it into the sole determining and all-overriding principle. These are the fact-minded men, in whom intellectual judgment, feeling, and intuition are driven into the background by the paramount importance of actual facts. When the accent falls on thinking, judgment is reserved as to what significance should be attached to the facts in question. And on this significance will depend the way in which the individual deals with the facts. If feeling is numinal, then his adaptation will depend entirely on the feeling value he attributes to them. Finally, if the numinal accent falls on intuition, actual reality counts only in so far as it seems to harbour possibilities which then become the supreme motivating force, regardless of the way things actually are in the present.
[985] The localization of the numinal accent thus gives rise to four function-types, which I encountered first of all in my relations with people and formulated systematically only very much later. In practice these four types are always combined with the attitude-type, that is, with extraversion or introversion, so that the functions appear in an extraverted or introverted variation. This produces a set of eight demonstrable function-types. It is naturally impossible to present the specific psychology of these types within the confines of an essay, and to go into its conscious and unconscious manifestations. I must therefore refer the interested reader to the aforementioned study.
[986] It is not the purpose of a psychological typology to classify human beings into categories—this in itself would be pretty pointless. Its purpose is rather to provide a critical psychology which will make a methodical investigation and presentation of the empirical material possible. First and foremost, it is a critical tool for the research worker, who needs definite points of view and guidelines if he is to reduce the chaotic profusion of individual experiences to any kind of order. In this respect we could compare typology to a trigonometric net or, better still, to a crystallographic axial system. Secondly, a typology is a great help in understanding the wide variations that occur among individuals, and it also furnishes a clue to the fundamental differences in the psychological theories now current. Last but not least, it is an essential means for determining the “personal equation” of the practising psychologist, who, armed with an exact knowledge of his differentiated and inferior functions, can avoid many serious blunders in dealing with his patients.
[987] The typological system I have proposed is an attempt, grounded on practical experience, to provide an explanatory basis and theoretical framework for the boundless diversity that has hitherto prevailed in the formation of psychological concepts. In a science as young as psychology, limiting definitions will sooner or later become an unavoidable necessity. Some day psychologists will have to agree upon certain basic principles secure from arbitrary interpretation if psychology is not to remain an unscientific and fortuitous conglomeration of individual opinions.