The Significance and Role of Natural Law Doctrine in the Development of International Law
Authors: Denysov Volodymyr 
Published: August 2023

Natural law, which has played a significant role in the formation and development of international law, continues to be a subject of debate due to the specific definition of it sessence as a legal ideology that transforms depending on the course of history and the tasks set in this process. This ideology is an integral part of legal thought exclusively within Western civilization, the creation of which began with the encounter of Medieval Europe, represented by the Catholic Church, with the ancient philosophy of Ancient Greece, particularly Stoicism, which was utilized by Ancient Rome in the formation of jusgentium as a component of Roman law by magistrates. It was particularly during this period that the doctrine of natural law, in line with the Romans' understanding of jusgentium as a universal law for all of humanity, acquired a universal significance and continues to be one of the pillars of Western legal thought to this day.

The spiritual, social, and political revolution in Europe marked by the Renaissance, the Reformation, and the rise of nation-states reshaped the concept of natural law,presenting it as a product of human intellect, namely, as human reason. Consequently,a new philosophical foundation emerged to justify international law among sovereign states, solidified by the Peace of Westphalia in 1648. The new paradigm of relations between states, influenced by the doctrine of natural law, found expression in Hugo Grotius' system of international law, characterized by objective causal connections. In this system, the doctrine of natural law underwent a shift where the postulates of God,while remaining recognized as a basis for its application, lost their decisive significance that characterized the medieval period.

The subsequent stages of the development of international law, gradually assuming a contractual character, are associated with the abandonment of the ideology ofnatural law, which in the 19th century was entirely replaced by theories of positivism such as empiricism, pragmatism, and logical positivism. After World War II, a process of "rebirth of positive law" is observed, characterized by the emergence of human rights protection at the international level, the functioning of the international judicial system, and the necessity of interpreting customary international law and general principles of law. Discussions surrounding the principles of the Nuremberg Tribunal Statute, adopted in 1945, have become a significant factor in the reassessment of natural law ideology. Various, often contradictory, views regarding the content and form of natural law compared to the positive norms of international law continue to be expressed.

The current crisis of international order and, consequently, international law it selfis leading to the emergence of separate economic and political enclaves, signifying a decline in the importance of universalism in international relations and marking the culmination of the revival period of natural law doctrine. This transition also demonstrates a shift towards a new form of regionalism independent of the UN Charter.

Key words: Roman law, jus gentium, nature law, international legal order,international law, international law philosophy, crisis of international relations andinternational law.