Thomism

Thomism is the philosophical and theological school that carries forward the legacy of Thomas Aquinas (1225–1274), the Dominican philosopher, theologian and Doctor of the Church, and that holds his main views on reality, God and the soul to be rationally defensible.

The name comes from its author. Thomas held that truth should be accepted wherever it is found, so he drew on Greek, Roman, Jewish and Islamic philosophers. He was a realist, convinced that the world can be known as it truly is. He largely followed the terminology and metaphysics of Aristotle, whom he commented on at length, often defending Aristotle's views with arguments of his own, and he kept some Neoplatonic principles, such as the idea of a first being that is essentially being and essentially good. His most influential work, the Summa Theologiae, became a central reference for medieval theology and is still studied in philosophy and theology faculties, especially at Catholic universities.

In its basic lines, the doctrine distinguishes essence from existence, act from potency, and substances from accidents. On this view, every being has a form that makes it what it is and a purpose that gives it meaning, and the chain of causes requires an uncaused first cause, which is called God. Thomistic texts also distinguish three ways of predicating: univocal, analogical and equivocal. For example, the word "healthy" applies analogically to a person and to a food that promotes health. A simple illustration: a knife is good if it cuts well, because it fulfils its function; for Thomism, everything that exists has a purpose and is, to that extent, good, while evil is understood as a privation of good.

The Catholic Church has recommended Thomas's teaching in many documents, and the Second Vatican Council proposed it as a guide for theological formation. From the nineteenth century, neo-Thomism sought to restore his thought against idealism and positivism; in the twentieth century, thinkers such as Jacques Maritain and Étienne Gilson defended its value as a rational inquiry. Today several currents coexist: traditional Thomism, renewed Thomism, which engages modern science and hermeneutics, and analytic Thomism, which applies the conceptual rigour of contemporary philosophy to Thomas's texts. The main debate concerns whether his claims can be demonstrated by reason without the support of faith, and which part of his metaphysics can still be defended today.