It has been the dream of philosophers that theoretical and abstract
science could and some day perhaps would succeed in putting into
formulae and into general terms all that was significant in the concrete
facts of life. It has been the tragic mistake of the so-called
intellectuals, who have gained their knowledge from textbooks rather
than from observation and research, to assume that science had already
realized its dream. But there is no indication that science has begun to
exhaust the sources or significance of concrete experience. The infinite
variety of external nature and the inexhaustible wealth of personal
experience have thus far defied, and no doubt will continue to defy, the
industry of scientific classification, while, on the other hand, the
discoveries of science are constantly making accessible to us new and
larger areas of experience.

What has been said simply serves to emphasize the instrumental character
of the abstract sciences. History and geography, all of the concrete
sciences, can and do measurably enlarge our experience of life. Their
very purpose is to arouse new interests and create new sympathies; to
give mankind, in short, an environment so vast and varied as will call
out and activate all his instincts and capacities.

The more abstract sciences, just to the extent that they are abstract
and exact, like mathematics and logic, are merely methods and tools for
converting experience into knowledge and applying the knowledge so
gained to practical uses.

IV. HISTORY, NATURAL HISTORY, AND SOCIOLOGY

Although it is possible to draw clear distinctions in theory between the
purpose and methods of history and sociology, in practice the two forms
of knowledge pass over into one another by almost imperceptible
gradations.

The sociological point of view makes its appearance in historical
investigation as soon as the historian turns from the study of "periods"
to the study of institutions. The history of institutions, that is to
say, the family, the church, economic institutions, political
institutions, etc., leads inevitably to comparison, classification, the
formation of class names or concepts, and eventually to the formulation
of law. In the process, history becomes natural history, and natural
history passes over into natural science. In short, history becomes
sociology.

Westermarck's _History of Human Marriage_ is one of the earliest
attempts to write the natural history of a social