Introduction to Law

definition of law, which was already given in the thirteenth century by the Christian
theologian and philosopher Thomas Aquinas.

According to this definition, the law is “arationalordering of things which concern the

common good, promulgated by whoever is charged with the care of the community”. This

definition was, by the way, not intended as a characterization of Roman law.

Natural Law During the seventeenth and eighteenth centuries, there was a strong
movement among learned legal writers that emphasized the rational nature of the
law, and some authors attempted to establish the content of law purely by means of
reasoning. Law that was established by means of reason was usually discussed
under the heading of natural law.

Hugo Grotius (1583–1645), developed in his bookDe iure belli ac pacis(On the Law of

War and Peace) the outlines of international law and private law on a rational basis.

Samuel von Pufendorf (1632–1694) developed in his bookDe officio hominis et civis juxta

legem naturalem libri duo(On The Duty of Man and Citizen According to the Natural Law)

large parts of private law, also on the basis of reasoning alone.

A similar enterprise was undertaken by Christian Wolff (1679–1754) in hisJus naturae

methodo scientifica pertractatum(Natural Law Dealt With by the Method of Science).

Rationalist law, along these lines, can be opposed to two forms of law that exist
as a matter of social fact, namely customary law and positive law in the sense of law
that was laid down (see Fig.1.1).

1.5 National States and Codification

Peace of Westphalia England was already, to a certain degree, united during the
eleventh century, but on the European continent the process of unification, in which

LAW

Rationalist law Law that exists as

social fact

Customary law Positive law

Fig. 1.1 Kinds of law

14 J. Hage