ese categories are taken for
real existences, or at least for organs of various functions in a real
existence, namely, society. We follow the analogy of an animal's body so
far as to describe the "structure" and the "functions" of a society,
even its "anatomy" and "physiology." These are pure metaphors. By the
structure of a society we mean the rules and the customs by which
occupations and enjoyments are distributed among its members; by its
functions we mean the habitual actions by which each man enters into
relations with the others. It may be convenient to use these terms, but
it should be remembered that the underlying reality is composed entirely
of habits and customs.

The study of institutions, however, obliges us to ask special questions
about persons and their functions. In respect of social and economic
institutions we have to ask what was the principle of the division of
labour and of the division into classes, what were the professions and
classes, how were they recruited, what were the relations between the
members of the different professions and classes. In respect of
political institutions, which are sanctioned by obligatory rules and a
visible authority, two new series of questions arise. (1) Who were the
persons invested with authority? When authority is divided we have to
study the division of functions, to analyse the _personnel_ of
government into its different groups (supreme and subordinate, central
and local), and to distinguish each of the special bodies. In respect of
each class of men concerned in the government we shall ask: How were
they recruited? What was their official authority? What were their real
powers? (2) What were the official rules? What was their form (custom,
orders, law, precedent)? What was their content (rules of law)? What was
the mode of application (procedure)? And, above all, how did the rules
differ from the practice (abuse of power, exploitation, conflicts
between executive agents, non-observance of rules)?

After the determination of all the facts which constitute a society, it
remains to find the place which this society occupies among the total
number of the societies contemporary with it. Here we enter upon the
study of international institutions, intellectual, economic, and
political (diplomacy and the usages of war); the same questions apply as
in the study of political institutions. A study should also be made of
the habits common to several societies, and of