from /relations between the ego and the unconscious/ by jung

"... but even in these lesser proportions the essence of the conflict is easily recognised: the arrogance of the one and the despondency of the other share a common uncertainty as to their boundaries. The one is excessively expanded, the other excessively contracted. their individual boundaries are in some way obliterated. if we now consider the fact that, as a result of psychic compensation, great humility stands very close to pride, and that "pride goeth before a fall," we can easily discover behind the haughtiness certain traits of an anxious sense of inferiority. in fact we shall see clearly how his uncertainty forces the enthusiast to puff up his truths, of which he feels none too sure, and to win proselytes to his side in order that his followers may prove to himself the value and trustworthiness of his own convictions. nor is he altogether so happy in his fund of knowledge as to be able to hold out alone; at bottom he feels isolated by it, and the secret fear of being left alone with it induces him to trot out his opinions and interpretations in and our of season, because only when convincing someone else does he feel safe from gnawing doubts."