This hypothesis, which also underlies our theory of “ab-reaction” (“Preliminary Communication”), can be used in the same sense as the physicist uses the assumption of the current of electric fluid. It is preliminarily justified through its usefulness in the comprehension and elucidation of diverse psychic states. CHAPTER VI. ON THE RIGHT TO SEPARATE FROM NEURASTHENIA A DEFINITE SYMPTOM-COMPLEX AS “ANXIETY NEUROSIS” (ANGSTNEUROSE). It is difficult to assert anything of general validity concerning neurasthenia as long as this term is allowed to express all that for which Beard used it. I believe that neuropathology can only gain by an attempt to separate from the actual neurosis all those neurotic disturbances the symptoms of which are on the one hand more firmly connected among themselves than to the typical neurasthenic symptoms, such as headache, spinal irritation, dyspepsia with flatulence and constipation, and which on the other hand show essential differences from the typical neurasthenic neurosis in their etiology and mechanism. If we accept this plan we will soon gain quite a uniform picture of neurasthenia. We will soon be able to differentiate—sharper than we have hitherto succeeded—from the real neurasthenia the different pseudoneurasthenias, such as the organically determined nasal reflex neurosis, the neurotic disturbances of cachexias and arteriosclerosis, the early stages of progressive paralysis, and of some psychoses. Furthermore, following the proposition of Moebius, some status nervosi of hereditary degenerates will be set aside and we will also find reasons for ascribing some of the neuroses which are now called neurasthenia to melancholia, especially those of an intermittent or periodic nature. But we force the way into the most marked changes if we decide to separate from neurasthenia that symptom-complex which I shall hereafter describe and which especially fulfills the conditions formulated above. The symptoms of this complex are clinically more related to one another than to the real neurasthenic symptoms, that is, they frequently appear together and substitute one another in the course of the disease, and both the etiology as well as the mechanism of this neurosis differs basically from the etiology and the mechanism of the real neurasthenia which remains after such a separation.