384 THE AMERICAN JOURNAL OF SOCIOLOGY
of the reactions between individuals and institutions have been very imperfectly observed ; that there are important phases of phenomena which have been virtually overlooked ; and, consequently, that the interpretations derived from partial observation and imperfect coordi- nation of facts must be considered as, at best, provisional, until there has been further investigation and correlation of reciprocally modify- ing social reactions. In view of all this, progressive solution of the present social problem clearly requires —
1. Extension of the method of positive observation to all classes of societary phenomena which have not been adequately observed.
2. Discovery of the relations between such of these phenomena as have been abstractly interpreted, i. e., in abstraction from the contain- ing reality.
3. Extension of the method of abstract interpretation to other homogeneous groups and other series of phenomena.
4. The highest possible generalizations of societary facts, by quali- tative or quantitative explanation of all reactions between individuals and groups, which can be seen to fix or to modify either individual or social types.
This study of reactions in general, between individuals and insti tutions, has never been distinctly proposed till the sociologists began to organize the study. Certain aspects of it have been studied ever since men began to think ; e. g., the reactions between rulers and ruled. Other aspects or abstractions have been made the subject- matter of very advanced and developed sciences (e. g., economics), but, as we see if we use the figure (opposite p. 382) in connection with the De Greef chart (p. 139), these are but fragments of the whole sub- ject, and until they are thought in connection with the whole, they must necessarily be very incomplete. As a challenge for criticism I offer, therefore, this thesis :
History, up to date, has not so much as intelligently attempted to map out the field of investigation in which we must discover the classes of knowledge that above diagram shows to be needed as a condition of under- standing the experience of men in society.
During the last century the historians have learned wonderfully how to do it, but they have incidentally unlearned what to do. They have found a method, but meanwhile have lost their problem. That is to say, if we let fall a line from the plane F G H I X.Q the plane A B CD — say from M^ to M (political institutions) — we shall have
