The most recent and now accepted theory for determining whether a regulation is public or civil law is the “modified subject theory”. A codified regulation is public law if at least one of the subjects is part of the state (“the state” as legislative, executive and judicial) or is legally authorized to act on behalf of a part of the state. This theory was necessary because the theory of “superordination” failed in certain situations, for example: A parent is legally superior to a minor. The minor may not sign a contract without the consent of one of the parents. According to the old theory, this would be a case of “superordination” that would qualify these regulations as public law. The new theory qualifies these regulations as private law, because although parents are superior, they are not part of the state and do not act on behalf of anyone. This particular issue occupies much of the court`s work and often reshapes the legal process itself when the court finds that a particular law actually interferes with citizens` rights. The decisions of other courts are modified only with regard to constitutional violations. Other errors are irrelevant. Here, too, European law has some influence, because the Fundamental Law is no longer the sole source of law, but is supplemented by the Treaties and laws of the European Union. In addition to the constitution of the Federal Republic of Germany, each state has its own constitution (see, for example, the Hamburg Constitution) and necessarily its own constitutional law and its own court. Nevertheless, the Basic Law and the Federal Constitutional Court are adapted to the actions of the Länder and their branches.

114 Other examples are Article 90a (and, in that context, a number of other new provisions on the legal status of animals) (see Helmut Heinrichs, in Palandt, Bürgerliches Gesetzbuch, 64th edition (2005), paragraph 90a, point 1: a `sentimental statement without effective legal content`) and Article 55a (see Palandt/Heinrichs (see above) § 55a, point 1: `against the legal order`). 4 The standard report is Franz Wieacker, A History of Private Law in Europe (1995) (translated by Tony Weir); see also Paul Koschaker, Europa und das römische Recht, 4th ed. (1966) (on the importance of Roman law for European legal culture); Helmut Coing, Europäisches Privatrecht, vol. I (1985); Vol. II (1989) (on the history of private law); Peter Oestmann, Rechtsvielfalt vor gericht (2002). For an overview, see Reinhard Zimmermann, “Roman Law and the Harmonization of Private Law in Europe”, in Arthur Hartkamp et al. (eds.), Towards a European Civil Code, 3rd ed. (2004), 21 et seq. The Constitution is called the Basic Law because the authors considered this legal “corpus” as a provisional document to be replaced by the constitution of a future unified Germany. In reaction to National Socialism, the Basic Law showed distrust of its own people and government and was created in reaction to the problems of the Weimar Constitution. Where the Weimar Constitution was weak, this Constitution was strong, the Basic Law was strong, where the Weimar Constitution left every decision to the free will of the legislature, the Basic Law defines the limits that no one can cross.

As far as possible, powers are limited and controlled. This frame of reference is intended to serve as a basis for further reflection on an optional instrument in the field of European contract law.204 The principles of European contract law developed by the “Lando Commission”205 constitute a model for such an instrument. Among academics across Europe, the desirability of a European civil code has become a hotly debated issue.206 Two international initiatives have already attempted to develop draft codes for contract law and beyond.207 A change of perspective is also emerging in legal education.208 The mobility of law students within the European Union is supported by the extraordinary success of the Erasmus Programme (now Socrates). More and more law schools are trying to give themselves a “European” profile through integrated study programmes. Institutes and chairs in European private law, European economic law and European legal history have been set up. The models of legal harmonisation of the European past209 and other parts of the world210 are receiving increasing attention. In addition, the national isolation of law and jurisprudence is overcome by the uniform private law provided for in international conventions. In this context, the success of the Convention on Contracts for the International Sale of Goods, which is beginning to play an increasingly important role in the private law jurisprudence of national supreme courts, is of paramount importance.211 The roughly described developments so far are also reflected in the emergence of a legal literature focused on European law, and not only on national law. It started in the field of comparative law and the history of law.212 Since then, a handbook on European contract law has been published,213 unjust and delictual enrichment,214 comparative case law,215 series of monographs on the history of European law and European private law,at least three legal journals devoted to European private law, 216 and collections of basic texts in this field.217 At the same time, it is clear that, for the foreseeable future, we will still be faced with the coexistence of a large number of national private law systems in Europe. However, there would be much to gain if these could be assimilated gradually or organically. This requires that those involved in national legal development are aware of what is happening in other national legal systems and, at European level, that they take a critical look at the particularities and particularities of their own legal systems and, wherever possible, adopt a harmonising approach.218 Those who determine the direction of European private law must take account of national legal experience, which is influenced by the requirement of legal experience.

The courts and legal authors have been collected.