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Treatise on Law

Thomas Aquinas

Natural law / Christian philosophy

A core natural-law text connecting law, reason, morality, divine order, and political authority.

About the author

Italian Dominican friar and theologian (1225–1274), the central figure of scholasticism and of the natural-law tradition. The Treatise on Law, drawn from his Summa Theologiae, distinguishes eternal, natural, human, and divine law, and argues that a human law that conflicts with natural law is 'no longer a law but a corruption of law.' This framework shaped Western legal and political thought for centuries and still anchors natural-law arguments about justice and the limits of state authority.

Synopsis

A philosophical account of eternal law, natural law, human law, divine law, and the moral foundations of legal order.

Core passage idea

Paraphrase · Public domain

Aquinas treats law as an ordinance of reason directed toward the common good.

This gives users a very different view from modern legal neutrality: law is tied to reason, morality, and the common good.

To avoid a bubble

Pair with modern secular theories of law and liberal neutrality.

Reading note

Best for users interested in natural law, religion, justice, and moral order.

Best paired with

John Stuart Mill, On Liberty.

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