When in a school everything revolves around a fundamental fact, and this fact is a natural phenomenon, the school will have entered the orbit of science. Then the teacher must assume those "characteristics" which are necessary in the presence of science. Among its devotees we find "characteristics" independent of the content of thought; in short, physicists, chemists, astronomers, botanists, and zoologists, though their content of knowledge is entirely different, are nevertheless all students of the positive sciences, and have characteristics which differentiate them from the metaphysicians of the past. These characteristics are related, not to the content, but to the method of the sciences. If, therefore, pedagogy is to take its place among the sciences, it must be characterized by its method; and the teacher must prepare herself, not by means of the content, but by means of the method. In short, she should be distinguished by _quality_ even more than by _culture_. The fundamental quality is the capacity for "observation"; a quality so important that the positive sciences were also called "sciences of observation," a term which was changed into "experimental sciences" for those in which observation is combined with experiment. Now it is obvious that the possession of senses and of knowledge is not sufficient to enable a person to observe; it is a habit which must be developed by _practise_. When an attempt is made to show untrained persons stellar phenomena by means of the telescope, or the details of a cell under the microscope, however much the demonstrator may try to explain by word of mouth what ought to be seen, the layman cannot see it. When persons who are convinced of the great discovery made by De Vries go to his laboratory to observe the mutations in the varied minute plants of the Aenothera, he often explains in vain the infinitesimal yet essential differences, denoting, indeed, a new species, among seedlings which have hardly germinated. It is well known that when a new discovery is to be explained to the public, it is necessary to set forth the coarser details; the uninitiated cannot take in those minute details which constituted the real essence of the discovery. And this, because they are unable to observe. To observe it is necessary to be "trained," and this is the true way of approach to science. For if phenomena cannot be _seen_ it is as if they did not exist, while, on the other hand, the _soul of the scientist_ is entirely possessed by a passionate interest in what he sees. He who has been "trained" to see, begins to feel interest, and such interest is the motive-power which creates the spirit of the scientist. As in the little child internal _coordination_ is the point of crystallization round which the entire psychical form will coalesce, so in the teacher interest in the phenomenon observed will be the center round which her complete new personality will form spontaneously.