"Many causes contribute to prevent students from attaining what after all should be the great object of their wishes--practical knowledge. The different sciences to which you are required to turn your attention successively possess so many fascinations that you may attach to some an undue degree of importance; but be assured of this, that however accurate be your knowledge of anatomy, healthy and morbid, however skilful you may be in the chemical theories and manipulations, however extensively you may have mastered the necessary properties of botany, however well you are acquainted with the nature and properties of drugs--be assured, I say, that you have acquired all this knowledge in vain unless you have diligently studied symptoms at the bedside of the patient and have observed the consequences and causes of disease in the dead room. In fact, in whatever other pursuits you may employ your afternoon hours, the morning should always be dedicated with earnestness to the hospital; from its wards all appearance of levity and inattention must be banished, for your neglect of the opportunities there presented for observation loads you with a serious amount of responsibility, I had almost said of guilt. It is no light thing to have life entrusted into your hands; we are all liable to err, we all commit mistakes; {179} the rules of our art are not invariably precise and certain; but they only are guilty who have not used every opportunity of acquiring practical knowledge; he is doubly guilty who, conscious of his neglect, embarks in practice and commences with the decision and boldness true experience alone can confer." At a comparatively early age Graves realized more than most men that medicine is an art and not a science, and that each individual case presents problems that have to be studied out for themselves and for which no general principles of diagnosis, prognosis or therapeutics serve. He appreciated that there was no royal road to medical wisdom, in the sense of a scientific shortcut by means of which manifestations of disease and their indications for treatment might be grouped together and easily learned. Nor, may we add, has any such road been found since. Each physician must train himself by patient, repeated observation, and without this discipline and training there can be no real success. Accordingly he said to his students in Dublin: