Introduction. The article reveals issues related both to the analysis of conceptual models of natural law and to the author's approach set out within the framework of the political and legal views of the classic of the pre-revolutionary school of legal positivism Gabriel Felixovich Shershenevich. Based on the analysis of G.F. Shershenevich's approach to the historical evolution and scientific validity of the theory of natural law, various variations of the ratio of morality and law depending on the ratio of natural law and positive law are shown. At the same time, conclusions are formulated that allow us to rethink the provisions of the assessment of the theory of natural law on the basis of an alternative reading of the provisions of the doctrine of legal positivism. Materials and Methods. The research materials were primary sources in the form of the works of G.F. Shershenevich himself, as well as scientific works that allow analyzing the conceptual features of the doctrine of legal positivism. In the course of the study, the dialectical method was applied, methods of generalization and grouping of data were used, as well as a comparative legal, historical and legal method. The Results of the Study made it possible to reveal the process of changing and developing doctrinal approaches to the theory of natural law, to identify the author's understanding of this issue by G.F. Shershenevich in the context of the relationship between natural and positive law and to formulate a modern reading of the theses of legal positivism in order to overcome their theoretical and practical controversial points. Findings and Conclusions. The analysis made it possible to clarify the historically variable nature of natural law, to update the understanding of the phenomenon of the correlation of natural and positive law in the context of the doctrine of legal positivism, as well as to assess the theoretical and practical significance of the author's approach of G.F. Shershenevich.