reason leave out of sight these elements which are dissimilar, incongruous, or even hostile or incompatible, and which, therefore, cannot be classed together or referred to any single law, scientific or empirical. This statement is true of every department of knowledge. It is notoriously true of political economy, whose principles are viewed in contrasted lights by the political parties which divide communities and even nations; it is also true of civil and criminal law, whose fundamental principles are accepted by all civilized peoples, but which in practice are not applied by any two alike; it is true even of moral science, whose foundations of right and wrong are recognized by all nations and in every age, but whose practical applications are as various as the communities that adopt them for their government; it is also true of every one of the arts of which scientific principles form the rational basis. Every particular instance requires a greater or less modification of the general principles involved in it. "Inventors, great and small, are rarely theorists; the invention must, before all things, be suited to the necessity, and the theory may come afterward if anybody cares for it. For a theory is nothing but an attempted explanation, and the fact must exist before it can possibly need explaining. Bread is a great invention against hunger, and a man needs to know nothing about gastric juices to save himself from starvation when the loaf is at hand" (M. Crawford). Political economists have never made successful statesmen; the most learned judges are far from being the best forensic lawyers; the profoundest analysts of moral motives are not always the most incorruptible and upright men; no acquaintance with the theory of colors will make a painter famous; no knowledge of the structure of language will make a poet or an orator; none of mechanics will create an accomplished engineer; and no familiarity with anatomy, etiology, pathology, or therapeutics and materia medica will of itself render a physician skilful in diagnosis and successful in the treatment of disease. To this end must be added the one thing needful, personal fitness, sagacity in recognizing the peculiarities of individual cases, and in adapting the treatment of them, hygienic, dietetic, and medicinal, to the special requirements of each. In a word, the physician must never forget that he has a patient as well as a disease to treat. It may be objected that attainments of such a judicial character as I have suggested are seldom to be met with in history or in one's own experience. That is very true; but it is no reason for rejecting a model that one cannot imitate it perfectly. The medical, like all other professions, is made
