The closest analogy to this behaviour in our nervous patients is provided by the forms of illness recently made so common by the war—the so-called _traumatic neuroses_. Of course similar cases had occurred before the war, after railway accidents and other terrifying experiences involving danger to life. The traumatic neuroses are not fundamentally the same as those which occur spontaneously, which we investigate analytically and are accustomed to treat; neither have we been successful so far in correlating them with our views on other subjects; later on I hope to show you where this limitation lies. Yet there is a complete agreement between them on one point which may be emphasized. The traumatic neuroses demonstrate very clearly that a fixation to the moment of the traumatic occurrence lies at their root. These patients regularly reproduce the traumatic situation in their dreams; in cases showing attacks of an hysterical type in which analysis is possible, it appears that the attack constitutes a complete reproduction of this situation. It is as though these persons had not yet been able to deal adequately with the situation, as if this task were still actually before them unaccomplished. We take this attitude of theirs in all seriousness; it points the way to what we may call an _economic_ conception of the mental processes. The term ‘_traumatic_’ has actually no other meaning but this _economic_ one. An experience which we call traumatic is one which within a very short space of time subjects the mind to such a very high increase of stimulation that assimilation or elaboration of it can no longer be effected by normal means, so that lasting disturbances must result in the distribution of the available energy in the mind.