Here we come to the central fact in the whole problem of stammering--a fact which, when it is widely enough known and appreciated, is certain to exert a far-reaching influence on the prevention of stammering, as well as its cure. Until very recently, few have been aware of this fact except a small group of foreign investigators, physicians with a psychological training, whose special business it has been to determine scientifically the possibilities, the limitations, and the exact procedures to be followed in supplementing, by wholly mental treatment, the ordinary medical and surgical treatment of disease. Impressed by the predominance of the mental factor in stammering, these investigators were particularly impressed by some of the peculiarities mentioned above--as, the ability of almost every stammerer to speak well when alone or when in a state of abstraction. Such peculiarities, they knew from long experience, bore a strong resemblance to oddities in the behaviour of victims of hysteria, psychasthenia, or other psychoneurosis, in all of which disorders there is a tendency for symptoms to disappear when the sufferer's attention is momentarily withdrawn from them. Accordingly, it seemed to the investigators quite possible that, in the last analysis, stammering was not so much a disease in itself as a psychoneurotic symptom. They were well aware, for reasons already set forth in these pages, that psychoneurotic disorders have their origin in emotional disturbances of one sort or another, which, occurring to a person of nervous temperament or rendered neurally unstable by a faulty upbringing, react adversely on the entire organism. Exactly what happens is that the emotional disturbance--whether it be a fright, a grief, a worry, or what not--while perhaps completely forgotten by the victim, so far as conscious recollection is concerned, remains subconsciously alive in his memory, is ever seeking to emerge again into conscious remembrance, and, failing to do this, takes its revenge, so to speak, by the production of disease symptoms ranging from mere eccentricities of thought and behaviour to symptoms mimicking those of true organic disease.