Moral and legal rules of obligation and duty have therefore
certain striking similarities enough to show that their common
vocabulary is no accident. These may be summarized as
follows. They are alike in that they are conceived as binding
independently of the consent of the individual bound and are
supported by serious social pressure for conformity; compliance
with both legal and moral obligations is regarded not as
a matter for praise but as a minimum contribution to social
life to be taken as a matter of course. Further both law and
morals include rules governing the behaviour of individuals
in situations constantly recurring throughout life rather than
special activities or occasions, and though both may include
much that is peculiar to the real or fancied needs of a particular
society, both make demands which must obviously be
satisfied by any group of human beings who are to succeed in
living together. Hence some forms of prohibition of violence
to person or property, and some requirements of honesty and
truthfulness will be found in both alike. Yet, in spite of these
similarities, it has seemed obvious to many that there are
certain characteristics which law and morals cannot share,
though in the history of jurisprudence these have proved most
difficult to formulate.