In the clinics and hospitals of the near future we may quite reasonably expect that the doctors will delegate all the preliminary work of diagnosis to machine operators as they now leave the taking of a temperature to a nurse. Such machine work may be only a registration of symptoms; but I can conceive machines which would sort out combinations of symptoms and deliver a card stating the diagnosis and treatment according to rule. It would not do the work done by the clinical instinct of the born healer; but the proportion of practising doctors possessing this instinct can hardly be more than ten per cent. With the rest the diagnosis follows from the symptoms; and the treatment is prescribed by the text-book. And the observation of the symptoms is extremely fallible, depending not only on the personal condition of the doctor (who has possibly been dragged to the case by his nightbell after an exhausting day), but upon the replies of the patient to questions which are not always properly understood, and for lack of the necessary verbal skill could not be properly answered if they were understood. From such sources of error machinery is free. [The doctor] knows that he can call in a specialist when a case is too difficult for him; but he does not know that he may be wearing himself out by trying to do in a very difficult and uncertain way things that he could get done with ease and certainty by a machine which his typist-secretary could operate.