140 THE AMERICAN JOURNAL OF SOCIOLOGY
in actual experience, we pass from one stage of comprehension to another, and discover interrelationships among various departments of fact in the world of people."
PART II. THE LOGIC OF THE PSYCHICAL SCIENCES.'
CHAPTER I.
SPECIAL INTRODUCTION.
These notes proceed upon the assumption that the student intend- ing to enter the field of the social sciences has prepared himself by mastering the methodology of the physical sciences, at least in its rudiments. He is supposed to understand the general correlations of the different aspects of the world of things, which concern, in turn, physics, chemistry, and biology. It is presumed that the student is sufficiently intelligent about the problems presented by the phenomena on the borderland between the world of things and the world of people to make logical use of knowledge that may be gained by special investigations within that territory, at least so far as the knowl- edge affects the conditions of the world of people. In other words, familiarity with the discussions cited at the head of this section is, from this point, taken for granted. Otherwise expressed, it is assumed that the phenomena represented by the lower section of the " base " in De Greef's chart (above, p. 139) are understood in their most gen- eral relations to all else represented by the chart. The foregoing presumptions lead to the further presumption that the student is pre- pared to take cognizance of what is represented by the upper section of the " base " in De Greef's chart. He must have differentiated the world of things from the world of people, and must have perceived that the world of people is composed of people. To get ahead in answer- ing the comprehensive question which makes our problem (above, p. 132), we are obliged to take due account of the fact that people are members of the animal kingdom. The laws of life reign among them before the laws of mind get control. Hence we cannot adjourn
^Vide Small, "The Sociologists' Point of View," American Journal of Sociology, September, 1897, pp. 155-70.
» Vide Spencer, The Study of Sociology ; Ward, " The Relation of Sociology to Cosmology, Anthropology, Psychology," American Journal of Sociology, September, 1895 — March, 1896, and Outlines of Sociology, chaps. 2-5; HvsLOP, The Science of Sociology ; WuNDT, 2. Bd., 1. Abtheil., passim, particularly pp. 514-80, "Die Logik der Biologie."
