Our logical explanation of the meaning of these four divisions naturally began with the interpretation of that science which usually takes precedence in popular thought--with the science of nature, that is, and passed then to those groups whose methodological situation is seen rather vaguely by our positivistic age. But as soon as we have once defined and worked out the boundary lines of each of these four divisions, it would appear more logical to change their order and to begin with that division whose material is those over-individual will-acts on which all possible knowledge must depend, and then to turn to those individual will-acts which determine the formulation of our present-day knowledge, and then only to go to the objects of knowledge, the over-individual and the individual ones. In short, we must begin with the normative sciences, consider in the second place the historical sciences, in the third place the physical sciences, and in the fourth place the psychical sciences. There cannot be a scientific judgment which must not find its place somewhere in one of these four groups. And yet can we really say that these four great divisions complete the totality of scientific efforts? The plan of our Congress contains three important divisions besides these. 5. _The Three Divisions of Practical Sciences_ The three divisions which still lie before us represent Practical Knowledge. Have we a logical right to put them on an equal level with the four large divisions which we have considered so far? Might it not rather be said that all that is knowledge in those practical sciences must find its place somewhere in the theoretical field, and that everything outside of it is not knowledge, but art? It cannot be denied indeed that the logical position of the practical sciences presents serious problems. That the function of the engineer or of the physician, of the lawyer or of the minister, of the diplomat or of the teacher, contains elements of an art cannot be doubted. They all need not only knowledge, but a certain instinct and power and skill, and their schooling thus demands a training and discipline through imitation which cannot be substituted by mere learning. Yet when it comes to the classification of sciences, it seems very doubtful whether practical sciences have to be acknowledged as special divisions, inasmuch as the factor of art must have been eliminated at the moment they are presented as sciences. The auscultation of the physician certainly demands skill and training, yet this practical activity itself does not enter into the science of medicine as presented in medical writings. As soon as the physician begins to deal with it scientifically, he needs, as does any scholar, not the stethoscope, but the pen. He must formulate judgments; and as soon as he simply describes and analyzes and explains and interprets his stethoscopic experiences, his statements become a system of theoretical ideas.