Thomism

Thomism is the philosophical and theological school that arose from the work and thought of Thomas Aquinas (1225–1274), the Dominican philosopher, theologian, and Doctor of the Church. In its broadest sense, Thomism denotes any system that follows Aquinas in philosophy and theology; in a narrower sense, it refers to the specific set of opinions held by the "Thomistic School," principally among Dominican writers, that have been contested by other thinkers who nonetheless profess to follow Aquinas. The Second Vatican Council described Aquinas's system as the "perennial philosophy," and Pope John Paul II called Thomas "a master of thought and a model of the right way to do philosophy."

Aquinas's philosophy is characterized by a distinctive set of metaphysical doctrines: the real distinction between essence and existence (the actus essendi), act and potency as the fundamental principles of change, the four causes, and the analogy of being. In theology, his Summa Theologica remains one of the most influential documents in medieval theology and continues to be a central point of reference for Catholic thought. The "Five Ways" (quinque viae) are his classical a posteriori arguments for the existence of God, grounded in sensory experience.

The history of Thomism spans more than seven centuries, evolving through several distinct periods. After Aquinas's death, his ideas faced opposition from the Condemnations of 1277 but were vindicated by his canonization in 1323 and the Council of Vienna (1311–1312). The Dominican Order adopted his teaching as its own, and by the mid-14th century the Summa Theologica had supplanted Peter Lombard's Sentences as the standard theology textbook. The School of Salamanca in the 16th century developed Thomistic thought in new directions, making foundational contributions to international law, just war theory, and economic thought.

After a period of decline in the 18th century, Thomism experienced a major revival following Pope Leo XIII's encyclical Aeterni Patris (1879), which mandated the restoration of scholastic philosophy in Catholic education. This Neo-Thomist revival flourished for nearly a century, producing major figures such as Jacques Maritain, Étienne Gilson, and Réginald Garrigou-Lagrange. The Second Vatican Council (1962–1965) marked a turning point, leading to Thomism's loss of its exclusive status in Catholic intellectual life. The 21st century has seen a notable resurgence of interest, with diverse schools including Ressourcement Thomism, Analytical Thomism, and renewed engagement with Aquinas's metaphysics.

: The Wikipedia article on Thomism provides a comprehensive overview of the school's history from the 13th century to the present, its distinctive philosophical positions, and the various modern Thomistic schools including Neo-Scholastic, Existential, Transcendental, Analytical, Lublin, and River Forest Thomism. : The Catholic Encyclopedia entry offers a detailed account of Thomism in both its broad sense and restricted sense, tracing the history from Aquinas's early opponents through his vindication, decline, and the Neo-Thomist revival under Leo XIII. : The research summary on the Five Ways covers their logical structure, metaphysical foundations in act and potency, the four causes, the rejection of infinite regress, and the method of resolutio. : The research summary on the 1277 condemnations covers the 219 propositions condemned by Bishop Tempier and the scholarly debate about whether Aquinas was a direct or indirect target. : The Wikipedia entry on the School of Salamanca covers its revival of Thomism at the University of Salamanca and its contributions to natural law, international law, and economic theory. : The research summary on Aeterni Patris covers the encyclical's call for the revival of scholastic philosophy, the historical context of Thomism's decline, implementation through Jesuit institutions, and the long-term impact including the reaction from the Ressourcement movement. : The research summary on Thomism after Vatican II covers the transition from pre-conciliar dominance through decline to 21st-century resurgence, including Ressourcement Thomism and contemporary pluralistic approaches.