A legal system is the most explicit, institutionalized,
and complex mode of regulating human conduct. At
the same time it plays only one part in the congeries
of rules which influence behavior, for social and moral
rules of a less institutionalized kind are also of great
importance. The complexity of the organization and
operations of a legal system has led to disagreements
about the best terms in which to describe the nature
of law, while the coexistence of law with social and
moral rules affecting conduct has generated discussion
about the exact nature of the relationships between
the different sets of rules. A further source of difficulty
is caused by the opposition or tension that sometimes
exists between legal and moral rules, as when a legal
prescription appears to violate the dictates of con-
science. This has led to discussion of the relationship
between the concept of law and ethical criteria.
