Ontology of Customary Law as Legal Certainty and Justice In The National Criminal Law System

Abstract

This study examines the ontological dimensions of customary law within the Indonesian national criminal law system, particularly following the enactment of Law Number 1 of 2023 concerning the Criminal Code (National Criminal Code). The objective of the study is to examine the intersection between demands for legal certainty (the positivist paradigm) and aspirations for substantive justice stemming from living law. The research method used is normative juridical with a statutory, conceptual, and case-based approach. The results show that ontologically, customary law is a manifestation of the "soul content" and indigenous legal consciousness of the Indonesian people, which is communal, religio-magical, and concrete. The recognition of the principle of material legality in Article 2 of the National Criminal Code marks a paradigm shift from mere commands from the ruler to the crystallization of dynamic social norms. However, this integration effort faces significant challenges, particularly in the formalization mechanism of customary law through Regional Regulations (Perda), which risks eroding the authenticity and flexibility of customary law itself. The study also highlights the importance of synchronizing customary sanctions as additional punishments and strengthening the principle of ne bis in idem for perpetrators who have already undergone customary sanctions to ensure restorative justice. The success of this integration requires strict oversight from the central government to ensure customary norms remain aligned with human rights and Pancasila values, leading to the full implementation of the National Criminal Code in 2026