From Van Der Hoops's Conscious Orientation.
The introvert of thinking-type also takes his systematized experience as his guide; but here the emphasis falls on the inner aspect, thus on the need for objective order and on laws and principles, according to which experience is generally systematized. Abstraction of that part of conscious experience which is revealed as constant and subject to general rules is regarded by the introverted thinker as something of vital significance. He tries to arrange the opinions which he takes over from others in a system of his own. In doing so, he will take up a more critical attitude in regard to the thought-material which he is taught than do extraverted thinkers, and his aim is to follow the guidance of his own opinions and convictions. In consequence, we find a most careful working-over of his own experience, but a tendency to leave out of his reckoning facts and points of view which are not known to him. While the strength of the extraverted thinker lies in his easy application of systematized knowledge, the introverted thinker is particularly good at comparing systems and principles. He feels at home among abstractions, and there are many fine shades of meaning in the world of his ideas. Also, as he is more skilled in introspection, he is better able to examine mental facts than is the extraverted psychologist.
Hence we see here a living contact with ideas, and subtle reflection and consideration, side by side with difficulty in expressing and applying what has been thought out, and a certain aloofness from the world of facts in general. There is thus in these people a contrast between their consciousness of the objectivity of their judgment, and their difficulty, of which they are equally conscious, in defending this judgment and securing its recognition by others. This produces, even in children of the type, a peculiar attitude. They are often reserved, somewhat timid and uncertain, and seem not to feel at home in the world. On the other hand, they will, at the same time, manifest an obstinate, somewhat pedantic decisiveness. They have not the cool logicality of the thinking extravert, but take up a more fanatical stand, which may easily degenerate into dogmatism and extreme pedantry. In general, both children and adults of this type are, as a result of their introversion, difficult to convince that they are mistaken. Their inner, logical reasoning makes them feel that they are right, and they may take up an attitude to the external world also, which might be expressed as follows: "That is my opinion, even if I can't prove it; whether you agree or not, it will not change it to the slightest degree."
At an early age they have learned that the fact that they inwardly regard something as true does not in the least mean that others will accept it. As a result, their attitude is, in general, more sceptical in regard to the validity of any truth than is that of a thinking extravert, and they are more inclined to allow for the existence of differing views, even when these do not entirely tally with theirs or with those of prevailing authorities. At the same time, however, this gives rise to a feeling of aloofness in regard to any generally recognized system of truth, for this often seems to them something quite unattainable. On the other hand, they never cease to be surprised that what seems so obvious to them should not be equally clear to others. Occasionally such people will go to great pains to express themselves as objectively and clearly as possible, but sometimes they give up the attempt and simply present their views in the form in which they arose. In the difficult language of some philosophers we find the effect of both influences — sometimes in strange combination. As a result of this somewhat sceptical and resigned attitude in regard to form, the judgments of introverted thinkers have often about them something cautious, cold or stiff-necked. It is as if they already reckoned on difficulty in convincing others. Jung says of this type: "Even if he goes as far as giving his thoughts to the world, he does not deal with them as a careful mother would with her children, but he exposes them as foundlings, and at the most he will be annoyed if they fail to make their way."
This inner conflict between certainty as regards conviction, and uncertainty as to how to maintain and apply this conviction in the world, intensifies thought concerning personal conflicts and problems. Hence many philosophically disposed persons belong to this type. They aim at having, at least inwardly, a foundation of pure ideals and definite principles for the ordering of their lives. Such people make, as it were, endless preparations for life; they constantly renew their efforts to perfect their equipment, so as to be equal to the fight for existence. This they do, not only in the big problems of life, but also in ordinary practical matters. They like to have a systematic view of the whole situation before entering on any new ground. In order to be able to adapt themselves, they need to have order in their life and work, and they love making programmes. When travelling, they eagerly study maps and guide-books, or they may even try to master the language of a foreign country, before ever they go there. Such people like to be able to foresee all the possible difficulties which may arise in their business or work, so as to be able to take precautions against them in good time. Occasionally this leads to the most elaborate reckoning with every important practical detail. Ford seems to me to be a good example of the potentialities in practical adaptation characteristic of the type, with his elaborate preparations down to the smallest detail coupled with a theoretical justification of all his ideas. In a mind less clear and with less insight into what is essential, this preparation may, however, lead to much fussiness and complexity, and in such cases much energy and attention is wasted in warding off imaginary dangers.
These thinking people are also found more especially among the male sex. Great philosophers, such as Kant, belong to them, and also many mathematicians and psychologists. Or they may be found in all kinds of practical and applied sciences, and taking leading roles as careful organizers, legislators or contractors. On occasion, however, they are unable to get over certain unpractical traits, and will then cause difficulties with their fanatical exactitude in details, or by everlastingly insisting on their pet principles in any discussion or practical undertaking. This makes co-operation with them in any large combine somewhat difficult. Socially, also, they are somewhat surly. Their attitude to others is more or less studied, seldom absolutely spontaneous. Here again, their systematic thinking stands between them and the world. Their words are usually carefully chosen and weighed, and thus are a kind of mask. People of this type are usually aware of this; but they see no possibility of adopting any different attitude. One usually learns to know them better in a smaller circle, where they will be more spontaneous, and even cordial or original; but even so, with a tendency to be awkward as a result of over-sensitiveness or irascibility. It is more easy to see them as they really are in some sphere in which they have begun to master the technique.
As among the extraverted thinkers, here, also, we may find keen concentration of will and constant activity. Since the introvert finds the motives for his aspirations more within himself, he is less dependent on external stimuli. This is counter-balanced, however, by greater susceptibility to inner difficulties, which, accordingly, may damage his working capacity. And while his independence of circumstances gives him great perseverance, even where initially no success is to be looked for, it may also happen that he will squander his best powers on something impossible from the practical point of view, without realizing this in time.
If the instinctive life manages to gain some influence, it will be conducted along definite paths by a controlling reason. As a rule, introverted thought finds support in the perceptual aspect of instinctive experience, since this represents its objective aspect. This type of thinker is, however, in philosophy, natural science and psychology, more inclined than the extravert to speculate on the nature of perception and the object. In addition, he is, as an introvert, more in touch with the subjective side of instinctual life. He is more conscious of the inner struggle between instinctual drives, and here also he will seek to create order with his reason, in which case it will depend on his principles as to how he will do this. The theorizing idealist, full of his ideal of the purity of love, and despising as filthy anything remotely associated with sex, will, in the inflexibility of his system, be not far removed from those who defend licence on the principle that nature must not be denied. Both attitudes are in point of fact calculated to evade the practical complications of the problem, and to keep it, so to speak, at a distance. The introverted thinker will sometimes have a great deal to say on such subjects; but he is not, for all that, better, or more skilled, in practice.
Intuition may also influence people of this type to a greater or less degree, giving them something original, which is, however, subdued, since it can only be permitted to play any part in their life after it has been carefully tested. Intuition also reveals to them the schemata and principles according to which thought may classify experience. But the immediate results of personal vision, both in regard to the internal and the external world, tend rather to be mistrusted, unless it is obvious that they will fit into the system. These results may, however, give rise to alterations and extensions in the system. Nevertheless, fine inspirations frequently remain unfruitful, owing to the ponderous way in which they are dealt with.
Feeling, again, gives rise to the chief difficulties in people of this type. Anything which conforms to their principles and views is allowed; but even this cannot easily find expression, owing to deficient familiarity with current modes of expression. As a result, people of this type will often display a strict conventionality, or else a childish disregard of these modes. Inwardly, their feelings, moods and impulses cause them much more unpleasantness than they do to the extraverted thinker, the latter being less aware of them. An introverted thinker, when in love, feels awkward, uncertain and ridiculous. He will try and talk himself out of his feelings, or else make endless preparations to give expression to them, which is, naturally, scarcely conducive to spontaneity.