The article is devoted to the analysis of the legal theories of P.I. Novgorodtsev and B.A. Kistyakovsky, based on the moral philosophy of I. Kant in comparison with the psychological theory of law of L.I. Petrazhitsky. The unity of the positions of Novgorodtsev and Kistyakovsky in focusing on the ethical aspects of law, as well as highlighting morality as the highest principle, is revealed. Attention is paid to the disclosure of neo-Kantian motives in the philosophy of law and in the (...) context of the development of the theory of natural law in Russia. The main content of the article is a consistent analysis of Novgorodtsevʼs ideas in their dynamics, compared with the neo-Kantian philosophy of law of Kistyakovsky. It is emphasized that the psychological theory of the source of Petrazhitskyʼs legal relations is in the same intention of thought with the motives of the Russian neo-Kantians, which allows them to be compared in the history of the development of the Russian theory of law. The modern scientific literature is analyzed in order to identify the problem of comparing different approaches in the history of Russian philosophy of law, in which German transcendental philosophy is one of the key foundations. The question of the independence of Russian scientists in the construction of ethical and legal doctrines is actualized, but, at the same time, a single motive is emphasized with the Kantian provision on the need to establish a general civil society on the principles of a developed system of rules and norms. (shrink)