Morbid anxiety is certainly the commonest neurotic symptom, and the theory of its pathogenesis has been the occasion of a very great deal of investigation,[15] with, in my opinion, very fruitful results. We meet it in the form of a general apprehensiveness of impending danger and evil, as the anxiety-neurosis, and also in hysteria in the form both of apparently causeless attacks of dread and of innumerable specific phobias. In all its forms its most striking feature is the disproportion between its intensity and its apparent justification, so that it seems at first sight extremely difficult to correlate with the biological view of fear as a useful instinct that guards against danger. Practically all modern investigations into its pathogenesis agree that it stands in the closest relation with unsatisfied and repressed sexuality, and, in my judgment, the conclusion that morbid anxiety represents the discharge of repressed and unconscious sexual hunger is one of the most securely established in the whole of psychopathology; it is impossible here to consider the extensive evidence in support of this conclusion, and I can only refer to the published work on the subject[16]. The next question is: What is the relation between morbid anxiety as seen in peace neuroses and real—_i.e_., objectively justified—fear, as seen in various situations of acute danger and so prominently in the war neuroses? The point of connection is the defensive character of the reaction. Morbid anxiety, as we are familiar with it in the peace neuroses, is a defensive reaction of the ego against the claims of unrecognised “sexual hunger” (_Libido_), which it projects on to the outside world—e.g., in the form of phobias—and treats as if it were an external object; it is, in a word, the ego’s fear of the unconscious. But there appears to be an important difference between it and “real” dread in that the latter concerns only the ego itself, arises only in connection with external danger to the ego, and has nothing to do with the desires of repressed sexual hunger. One is tempted to say that the latter (real dread) is a normal protective mechanism that has nothing to do with the abnormal mechanism of morbid anxiety. Here, however, as elsewhere, the line between normality and abnormality is not so absolute as might appear, and consideration of the matter leads one to examine more closely into the nature of real dread itself. We then see that this can be dissected into three components, and that the whole reaction is not appropriate and useful as is commonly assumed. The reaction to external danger consists normally of a mental state of fear, which will be examined further in a moment, and in various activities suited to the occasion—flight, concealment, defence by fighting, or even sometimes by attacking. On the affective side there is, to begin with, a state of anxious preparedness and watchfulness, with its sensorial attentiveness and its motor tension. This is clearly