The comparative study of the various legal systems may show how different legal regulations for the same problem function in practice.
Conversely, sociology of law and law & economics may help comparative law answer questions, such as: believed that, for purposes of classifying the (then) contemporary legal systems of the world, it was required that those systems per se get studied, irrespective of external factors, such as geographical ones.
According to David, the Civil law legal systems included those countries where legal science was formulated according to Roman law, whereas Common law countries are those dominated by judge-made law.
The characteristics that he believed uniquely differentiate the Western legal family from the other four are: Konrad Zweigert and Hein Kötz propose a different, multidimensional methodology for categorizing laws, i.e. They maintain that, to determine such families, five criteria should be taken into account, in particular: the historical background, the characteristic way of thought, the different institutions, the recognized sources of law, and the dominant ideology.
Studies of these specific areas may be viewed as micro- or macro-comparative legal analysis, i.e.
detailed comparisons of two countries, or broad-ranging studies of several countries.Comparative law would be applicable to private international law when developing an approach to interpretation in a conflicts analysis.Comparative law may contribute to legal theory by creating categories and concepts of general application.The notion of legal transplants was coined by Alan Watson, one of the world's renowned legal scholars specializing in comparative law.Also, the usefulness of comparative law for sociology of law and law and economics (and vice versa) is very large.Also, in Chapter XI (entitled 'How to compare two different Systems of Laws') of Book XXIX, discussing the French and English systems for punishment of false witnesses, he advises that "to determine which of those systems is most agreeable to reason, we must take them each as a whole and compare them in their entirety." Yet another place where Montesquieu's comparative approach is evident is the following, from Chapter XIII of Book XXIX: As the civil laws depend on the political institutions, because they are made for the same society, whenever there is a design of adopting the civil law of another nation, it would be proper to examine beforehand whether they have both the same institutions and the same political law.In his 1861 work Ancient Law: Its Connection with the Early History of Society, and Its Relation to Modern Ideas, he set out his views on the development of legal institutions in primitive societies and engaged in a comparative discussion of Eastern and Western legal traditions.Comparative law is the study of differences and similarities between the law (legal systems) of different countries.More specifically, it involves the study of the different legal "systems" (or "families") in existence in the world, including the common law, the civil law, socialist law, Canon law, Jewish Law, Islamic law, Hindu law, and Chinese law.Comparative law in the US was brought by a legal scholar fleeing persecution in Germany, Rudolf Schlesinger.Schlesinger eventually became professor of comparative law at Cornell Law School helping to spread the discipline throughout the US.