The problem presenting itself in the adoption of a classification purely for statistical purposes was not a question of a scientific grouping of the psychoses based on either etiological, anatomical, pathological, clinical or prognostic considerations. It was a question of compiling a tabulation or list of clinical entities recognized generally by American psychiatrists, subject to such changes and modifications as may be necessary to make it conform to accepted standards. As a matter of fact, no adequate reason for a classification of mental diseases for any other than statistical purposes has even been advanced by the authors of our textbooks on psychiatry. They do not contribute anything of value whatever to our knowledge of symptomatology, diagnosis or treatment. Practically the only point on which the writers of our textbooks agree is that there is no one fundamental principle upon which a satisfactory classification can be based. It is unfortunate that tradition seems to demand the serious consideration of a problem which many believe admits of no solution and which would mean little or nothing to the future of psychiatry if it were solved. The views of the Committee on Statistics are shown by a quotation from the report made to the Association at its meeting in New York in 1917:—"Your Committee feels that the first essential of a uniform system of statistics in hospitals for the insane is a generally recognized nomenclature of mental diseases. The present condition with respect to the classification of mental diseases is chaotic. Some states use no well-defined classification. In others the classifications used are similar in many respects but differ enough to prevent accurate comparisons. Some states have adopted a uniform system, while others leave the matter entirely to the individual hospitals. This condition of affairs discredits the science of psychiatry and reflects unfavorably upon our Association, which should serve as a correlating and standardizing agency for the whole country. The large task of your Committee therefore has been the formulation of a classification which it could unanimously recommend for adoption by the Association. The task was accomplished only after several prolonged conferences at which classifications now in use in various states and countries, and the recommendations of leading psychiatrists were considered. The classification finally adopted is simple, comprehensive and complete; it copies no other classification but includes the strong features of many others; it meets the demands of the best modern psychiatry but does not slavishly follow any single system. In short, your Committee has endeavored to formulate a classification that could be easily used in every hospital for the insane in this country and that would meet the scientific demands of the present day."