is a term. These activities must
be referred primarily to desires, but the desires themselves may be
further referred to certain universal interests. In this character the
individual becomes one of the known or assumed terms of sociology. The
individual as a center of active interests may be thought both as the
lowest term in the social equation and as a composite term whose factors
must be understood. These factors are either the more evident desires,
or the more remote interests which the individual's desires in some way
represent. At the same time, we must repeat the admission that these
assumed interests are like the atom of physics. They are the
metaphysical recourse of our minds in accounting for concrete facts. We
have never seen or touched them. They are the hypothetical substratum of
those regularities of conduct which the activities of individuals
display.

We may start with the familiar popular expressions, "the farming
interest," "the railroad interest," "the packing interest," "the milling
interest," etc., etc. Everyone knows what the expressions mean. Our use
of the term "interest" is not co-ordinate with these, but it may be
approached by means of them. All the "interests" that are struggling for
recognition in business and in politics are highly composite. The owner
of a flour mill, for example, is a man before he is a miller. He becomes
a miller at last because he is a man; i.e., because he has interests--in
a deeper sense than that of the popular expressions--which impel him to
act in order to gain satisfactions. The clue to all social activity is
in this fact of individual interests. Every act that every man performs
is to be traced back to an interest. We eat because there is a desire
for food; but the desire is set in motion by a bodily interest in
replacing exhausted force. We sleep because we are tired; but the
weariness is a function of the bodily interest in rebuilding used-up
tissue. We play because there is a bodily interest in use of the
muscles. We study because there is a mental interest in satisfying
curiosity. We mingle with our fellow-men because there is a mental
interest in matching our personality against that of others. We go to
market to supply an economic interest, and to war because of some social
interest of whatever mixed or simple form.

With this introduction, we may venture an extremely abstract definition
of our concept "interest." In general, _an interest is an unsatisfie