Saint Thomas Aquinas (1225–1274) is widely considered the greatest philosopher and theologian of the medieval period. Born into a noble family in Aquino, Italy, he joined the Dominican Order against his family's wishes and went on to produce one of the most comprehensive syntheses of Christian theology and Aristotelian philosophy ever written.
His masterwork, the Summa Theologiae, organized Catholic doctrine into a coherent whole and addressed the relationship between faith and reason, the existence and nature of God, the sacraments, the virtues, and the moral life. It remains a primary reference for Catholic theology and philosophy.
Pope Leo XIII, in his encyclical Aeterni Patris (1879), declared Aquinas the foremost Catholic philosopher and recommended his works as the foundation of Catholic intellectual formation.
