The Natural-Law Doctrine of Hugo Grotius: The Origins of Classical Ideal of Rationality and Legal Thought

Introduction. This article is dedicated to the natural law doctrine of the Dutch jurist Hugo Grotius, examined within the context of the evolution of historical types of rationality.Methodology and materials. The study employs historical-philosophical, linguosemiotic, cultural, comparative-historical, legal-dogmatic, and systemic methods to investigate Grotius’s seminal work “On the Law of War and Peace.” In this analysis, Grotius’s views on natural law are juxtaposed with the writings of ancient Greek philosophers and Roman jurists, whose natural law doctrines embodied the essential characteristics of the pre-classical type of rationality.Results and Discussion. Classical jusnaturalism, of which Grotius was a prominent representative, significantly influenced the development of legal science and scientific methodology. Its evolution encompassed several stages, corresponding to the main types of rationality and conceptual legal thought. During the pre-classical stage of rationality, shaped by the works of ancient philosophers and Roman jurists, the categorization of legal thought and the emergence of legal science took place.The ideal of pre-classical rationality is the description and systematization of legal facts based on abstractly formulated general principles of natural law. The ideal of classical rationality, to which Grotius made a notable contribution, involves the typification of facts and the description of stable causal relationships among them.Conclusions. The natural law ideas of Hugo Grotius are foundational not only to contemporary legal science but also contributed to the formation of modern legal systems, which are normative structures organized according to the principles of formal logic (both predicative and deontic).