The philosophical ideas of the time had considerable influence on the medical theories of Hippocrates and his successors. The universe was considered as constituted by four elements: earth, air, fire, water. To each of these elements a special quality was attributed, and, thus, one recognized four fundamental qualities, viz., cold, dryness, heat, and moisture. Man—the most perfect being—was regarded as a “microcosmos,” or small world in himself, that is, a sort of compendium of the whole universe, and his organism, in correlation to the four primordial elements of the universe, was believed to be constituted of four fundamental humors—the blood, the pituita or mucus, the yellow bile, and the black bile or atrabile. Health, says Hippocrates,[46] depends on the just relation one to another of these principles, as to composition, force, and quantity, and on their perfect mixture; instead, when one of the four principles is wanting or in excess, or separates itself from the other components of the organism, one has a diseased condition. In fact, he adds, if some one humor flow from the body in a measure superior to its superabundance, such a loss will occasion illness. If, then, the humor separated from the others collect in the interior of the body, not only the part that remains deprived of its presence will suffer, but also that into which the flow takes place and where the engorgement is produced. We have here briefly stated these generalities in order to make ourselves clearly understood in speaking hereafter on different subjects, whether with regard to Hippocrates or to other authors of the time. In the works of Hippocrates there is not one chapter that treats separately of the affections of the teeth, just as there is no book in which he speaks separately of diseases of the vascular or nervous systems, and so on. There are, nevertheless, a great number of passages scattered throughout the Hippocratic collection from which we can deduce very clearly the great importance that the Father of Medicine ascribed to the teeth and to their maladies.