French philosopher, the leading figure of the 20th-century Thomist revival, and the principal Catholic voice in the formulation of mid-century international human-rights language. Born into a Protestant family and educated at the Sorbonne, Maritain — together with his wife and lifelong intellectual partner Raïssa Oumançoff — converted to Catholicism in 1906 under the influence of Léon Bloy, and devoted the rest of his life to a project that most interwar European intellectuals would have thought impossible: a rigorous philosophical reappropriation of Thomas Aquinas for modern political, aesthetic, and metaphysical problems. He taught at the Institut Catholique in Paris, at the Pontifical Institute of Medieval Studies in Toronto, at Princeton, and at Notre Dame, and served as French ambassador to the Vatican (1945–1948).
Integral Humanism (1936) is the central political book — the argument that modern secular humanisms (liberal, Marxist, fascist) each begin by severing humanity from its transcendent reference and end by cutting short their own humanism, and that a genuinely integral humanism requires the recovery of a theological anthropology. The book was a central intellectual influence on Christian Democratic political thought across post-war Europe and Latin America — including, at one remove, on the Second Vatican Council and the "preferential option for the poor" that Gutiérrez would later articulate against Maritain's more conservative followers. The Rights of Man and Natural Law (1942) and his work on the 1948 UN Universal Declaration of Human Rights (where he was the central Catholic drafter alongside Charles Malik and P.C. Chang) provided the philosophical framework that allowed Catholics, Protestants, Muslims, Confucians, and secular liberals to converge on a shared declarative text without a shared metaphysics — the "convergence without agreement" formula that he thought the 20th century most needed.
His aesthetics (Art and Scholasticism, 1920; Creative Intuition in Art and Poetry, 1953) shaped a generation of Catholic artists and writers; Dorothy Day cited him repeatedly, Merton read him in the novitiate, O'Connor and Percy both drew on his work. His late years, after Raïssa's death, were spent with the Little Brothers of Jesus in Toulouse — the philosopher-ambassador ending his life in a simple religious community.