The article analyzes the methodological problems of fundamental jurisprudence. The evolution of thebackbone legal science — the theory of state and law is shown. Its prototype was the encyclopedia of legalsciences, representing in a compressed form the entire body of knowledge about law. In Russia, a full legalencyclopedia appears in the 30s of the XIX century. However, domestic science did not follow the path ofencyclopedism — Russian lawyers focused their attention on understanding concepts and creating legalconcepts. The Encyclopedia of Law actually merged with its general theory. In Soviet times, the problemsof the theory of state and law and the philosophy of law were not separated either methodologically or incontent. During this period, the science of the theory of state and law was an inseparable material on issuesof jurisprudence: the theory of state and law, the history of political and legal doctrines, the philosophy oflaw, the sociology of law, and constitutional law (Soviet state law). At the turn of the 20th-21st centuries,significant changes took place in Russian jurisprudence that influenced the methodology of cognition of law.If for the Soviet legal science there was the only true Marxist-Leninist methodology for the study of state andlaw, then in the conditions of the de-ideologization of social sciences, the authors defend the pluralism oflegal understanding. Modern scientific literature states that the methods of cognition used by legal schools can be different and even mutually exclusive. It is recognized that the methodology sets the point of viewfrom which the researcher evaluates the law, and since these methods are poorly compatible, different viewson the essence of law and the state become an objective reality. A consequence of the pluralistic approachto the study of social phenomena was the need to distinguish between related sciences of the historical andtheoretical cycle.