An Analysis of Natural Law Jurisprudence in the Thought of Saint Thomas Aquinas

Abstract

This study aimed to: (1) examine the development of natural law jurisprudence; (2) investigate the structure of natural law in the thought of Saint Thomas Aquinas; and (3) analyze the criteria for the legitimacy of human law within the framework of the relationship among reason, morality, and the common good. This study employed documentary research, drawing on Aquinas’s primary works as well as relevant books, scholarly articles, and research studies. The data were analyzed through thematic classification, interpretation, and synthesis in accordance with the research objectives.
The findings revealed that:
1. Natural law jurisprudence developed from the search in Greek philosophy for principles of justice that transcend the commands of rulers to a theological account of law in the Middle Ages. A fundamental principle of the natural law tradition is that law does not acquire legitimacy merely because it is enacted by the state; rather, it must be grounded in reason, justice, and morality.
2. Aquinas conceptualized law as comprising four interrelated types: eternal law, natural law, human law, and divine law. Human beings apprehend the fundamental principles of natural law through reason, while human law specifies these principles in ways appropriate to particular social circumstances and must be directed toward the common good.
3. The legitimacy of human law is determined by its source, content, and purpose. Law must be enacted by an authority responsible for the community, be consistent with reason and justice, and be directed toward the common good. A defective or unjust law may lack binding force in conscience; however, noncompliance must also be considered in light of social order and the potential harm that may result to the common good.