These objections to be significant should frankly assert that between physical facts and mental facts, between bodies and minds, between any and all of the animal’s movements and its states of consciousness, there is an impassable gap, a real discontinuity, found nowhere else in science; and that by making psychology responsible for territory on both sides of the gap, one makes psychology include two totally disparate groups of facts, things and thoughts, requiring totally different methods of study. This is, of course, the traditional view of the scope of psychology, reiterated in the introductions to the standard books and often accepted in theory as axiomatic. It has, however, already been noted that in practice psychologists do study facts in disregard of this supposed gap, that the same term refers to facts belonging some on one side of it and some on the other, and that, in animal psychology, it seems very unprofitable to try to keep on one side or the other. Moreover, the practice to which the study of animal and child psychology leads is, if I understand their writings, justified as a matter of theory by Dewey and Santayana. If then, as a matter of scientific fact, human and animal behavior, with or without consciousness, seems a suitable subject for a scientific student, we may study it without a too uneasy sense of philosophic heresy and guilt. The writer must confess not only to the absence of any special reverence for the supposed axiom, but also to the presence of a conviction that it is false, the truth being that whatever feature of any animal, say John Smith, of _Homo sapiens_, is studied—its length, its color of hair, its body temperature, its toothache, its anxiety, or its thinking of 9 × 7—the attitude and methods of the student may properly be substantially the same. Of the six facts in the illustration just given, the last three would by the traditional view be all much alike for study, and all much unlike any of the first three. The same kind of science, physical science, would be potent for the first three and impotent for the last three (save to give facts about certain physical facts which ‘paralleled’ them). Conversely one kind of science, psychology, would by the traditional view deal with the last three, but have nothing to say about the first three. But is there in actual fact any such radical dichotomy of these six facts as objects of science? Take any task of science with respect to them, for example, identification. A score of scientific men, including John Smith himself, are asked to identify John’s stature at a given moment. Each observes it carefully, getting, let us say, as measures: 72.10 inches, 72.11, 72.05, 72.08, 72.09, 72.11, etc. In the case of color of hair each observes as before, the reports being brown, light brown, brown, light brown, between light brown and brown, and so forth.