To ask this question is not to throw discredit on the great work that Prof. Kraepelin has done for psychiatry. Indeed, the opinion may be frankly recorded that no conception dealing with mental disease advocated during the last fifty years has been more fruitful of beneficial results than that of dementia praecox. Out of a symptomatology which before had been more or less chaotic and disheartening Kraepelin evolved a scheme which, if it did not introduce perfect order, certainly marked a very great advance. And not the least of the benefits that psychiatry has derived from him, has been the greater accuracy of observation that his views have enforced upon all clinicians who desire to make an exact diagnosis or prognosis.