The Treatise on Law

The Treatise on Law is a collection of essays by Saint Thomas Aquinas, drawn primarily from his most significant work, Summa Theologiae. The impact of Aquinas on Western law and ethics cannot be overstated. The venerated Dominican Friar and Catholic priest was an important Doctor of the Church during the 13th century and his writings on theology and philosophy have shaped church doctrine and Western political theory for centuries. Aquinas argued that all laws made by man must be measured against Divine Law, or the plan by God for humanity. Only those laws consistent with God's command to love thy neighbors as thyself and to love God above all others are truly just laws. All morality flows from this Divine Law and whether something is ethical may only be judged by its action or effect. Aquinas argued that the cardinal virtues of justice, fortitude, prudence, and temperance are ordained by God and these principles must guide all just political and legal systems. The Treatise on Law brings together some of Aquinas' most influential ideas in one volume so that their impact on our moral and legal systems may be better understood.