agistrates, and the soldiers who in the last resort must be called
out to enforce the decrees of the community, it might appear that law
could not exist. And certainly it is hard to admit that what is known
as mob-law is any law at all. For historical purposes, however, we
must be prepared to use the expression "law" rather widely. We must
be ready to say that there is law wherever there is punishment on the
part of a human society, whether acting in the mass, or through its
representatives. Punishment means the infliction of pain on one who
is judged to have broken a social rule. Conversely, then, a law is
any social rule to the infringement of which punishment is by usage
attached. So long as it is recognized that a man breaks a social rule
at the risk of pain, and that it is the business of everybody, or of
somebody armed with the common authority, to make that risk a reality
for the offender, there is law within the meaning of the term as it
exists for anthropology.

Punishment, however, is by its very nature an exceptional measure.
It is only because the majority are content to follow a social rule,
that law and punishment are possible at all. If, again, every one
habitually obeys the social rules, law ceases to exist, because it
is unnecessary. Now, one reason why it is hard to find any law in
primitive society is because, in a general way of speaking, no one
dreams of breaking the social rules.

Custom is king, nay tyrant, in primitive society. When Captain Cook
asked the chiefs of Tahiti why they ate apart and alone, they simply
replied, "Because it is right." And so it always is with the ruder
peoples. "'Tis the custom, and there's an end on't" is their notion
of a sufficient reason in politics and ethics alike. Now that way lies
a rigid conservatism. In the chapter on morality we shall try to
discover its inner springs, its psychological conditions. For the
present, we may be content to regard custom from the outside, as the
social habit of conserving all traditional practices for their own
sake and regardless of consequences. Of course, changes are bound to
occur, and do occur. But they are not supposed to occur. In theory,
the social rules of primitive society are like "the law of the Medes
and Persians which altereth not."

This absolute respect for custom has its good and its bad sides. On
the one hand, it supplies the element of discipline; without which
any society is bound soon to fall to pieces. We