METHODOLOGY OF THE SOCIAL PROBLEM I 25
most complex substances and processes. They can reproduce only those that are comparatively simple. The chemist may easily separate water into its component gases. He reunites them only with the greatest difficulty, but he cannot at all produce artificially some of the most common natural com- pounds of several chemical elements.
For similar reasons, synthesis is of limited availability m the psychical sciences. Most psychological, social, and historical facts are of too complicated nature to permit any other than analytical investigation of any great scope and precision. In psychology synthetical experiment is possible to a limited extent. In like manner economic science has arrived at certain synthetic constructions. These, however, have only a hypothetical value. They rest on the assumption that certain conditions exist. This assumption may never quite correspond with the facts.
In all this there is caution and instruction for the sociologist. We are at once put on our guard against the expectation that a way may be quickly found to reconstruct our forms of thought about life. Still less may we anticipate the invention of ways to reconstruct the forms of life itself. In reducing life to systematic formulation we are shut up very closely to report- ing, with necessary analytical precision, facts as they are. The moment we venture upon construction of the elements of life into new combinations, we run the risk of falsifying some of the essential elements of the combination.
III. ABSTRACTION.
Abstraction means eliminating certain elements from a complex concep- tion or group of conceptions and retaining the remaining elements as compo- nents of a concept.
E. g., we will take the concept " plant," understanding by it a member of the vegetable kingdom in the widest sense, as distinguished from an animal. If, now, we throw out notion after notion, belonging within this general conception, we shall have an abstraction left. Thus, plants live dif- ferent periods, from a few moments to centuries. We will throw out all but ability to live a long term of years. Plants grow in the water, from the air, on other plants, and on animals. We will throw out all but the idea of growth from the ground. Plants are of one stem or many stems. We leave out all but the one. They creep along the ground, or climb upon walls, or other supports, or stretch upright into the air without support. We will throw out all but the last idea. Plants are of all sizes, from microscopic littleness to the height of hillocks. We will exclude all but the height of twenty feet or more. We have now an abstraction from the plant kingdom. We have singled out a subject of that kingdom. Its description is (its individuality, that in which all the other subjects of the kingdom are not precisely like it), "a perennial plant which grows from the ground, with a single, perma- nent, woody, self-supporting trunk or stem, ordinarily to a height of at least VN^rAy-iist o\ \M\\\.y le.&\." (Century Dictionary). But this individual of the
