From this short account of the process of insight, its relation to perception and introspection becomes pretty plain.  On the one hand, it closely resembles sense-perception, since it proceeds by the interpretation of a sense-impression by means of a representative image.  On the other hand, it differs from sense-perception, and is more closely allied to introspection in the fact that, while the process of interpretation in the former case is a reconstruction of external experiences, in the latter case it is a reconstruction of internal experiences.  To intuit another’s feeling is clearly to represent to ourselves a certain kind of internal experience previously known, in its elements at least, by introspection, while these represented experiences are distinctly referred to another personality.

And now we see what constitutes the object of insight.  This is, in part, a common experience, as in the case of sense-perception and aesthetic intuition, since to perceive another’s feeling is implicitly to cognize the external conditions of a common insight.  But this is clearly not the whole, nor even the main part of objective reality in this act of cognition.  An intuitive insight differs from a sense-perception in that it involves an immediate assurance of the existence of a feeling presentatively known, though not to our own minds.  The object in insight is thus a presentative feeling as in introspection, though not our own, but another’s.  And so it differs from the object in sense-perception in so far as this last involves sense-experiences, as muscular and tactual feelings, which are not at the moment presentatively known to any mind.

Illusions of Insight.

And now we are in a position, perhaps, to define an illusion of insight, and to inquire whether there is anything answering to our definition.  An illusory insight is a quasi-intuition of another’s feelings which does not answer to the internal reality as presentatively known to the subject himself.  In spite of the errors of introspection dealt with in the last chapter, nobody will doubt that, when it is a question between a man’s knowing what is at the moment in his own mind and somebody else’s knowing, logic, as well as politeness, requires us to give precedence to the former.

An illusion of insight, like the other varieties of illusion already dealt with, may arise either by way of wrong suggestion or by way of a warping preconception.  Let us look at each of these sources apart.

Our insights, like our perceptions, though intuitive in form, are obviously determined by previous experience, association, and habit.  Hence, on its passive side, an illusion of insight may be described as a wrong interpretation of a new or exceptional case.  For example, having associated the representation of a slight feeling of astonishment with uplifted eyebrows, we irresistibly tend to see a face in which this is a constant feature as expressing this particular shade of emotion.  In this way we sometimes fall into grotesque errors as to mental traits.  And the most practised physiognomist may not unfrequently err by importing the results of his special circle of experiences into new and unlike cases.