In spite of attempts at classification, most observers will agree that the disease known as neurasthenia has no definite boundary line. However strict an attempt is made to define its limitations, everyone who has to do with these cases must admit that the symptoms frequently merge into those associated with other conditions, such as those known as psychasthenia, melancholia, hypochondriasis, anxiety neuroses, obsessions and others. Even hysteria in its less pronounced forms is not always easy to separate from neurasthenia, and in not a few instances some of the salient features of both diseases may be present at the same time, and that this close association is recognised is shown by arguments that have occasionally been put forward for placing the disease known as traumatic neurasthenia into the category of traumatic hysteria. All classification is artificial and provisional, but useful and necessary as it is for studying the general group aspects of disease, there is the danger of over-estimating its importance, and of being tempted to feel the necessity of labelling a disease and then treating it according to such rules as are applicable to the label which has been placed upon it.