Thomas Aquinas, an Italian priest of the Catholic Church in the Dominican Order, was an influential philosopher and theologian in the tradition of scholasticism. He is widely regarded as one of the most significant medieval thinkers in Western philosophy and theology.

Born around 1225 in Roccasecca, in the Kingdom of Sicily, Thomas was a proponent of natural theology and is considered the father of 'Thomism,' a philosophical school that combines theology and philosophy based on the principles of natural law accessible through human reason. He synthesized Aristotelian philosophy with Christian principles, significantly influencing ideas about human liberty and moral governance.

His most famous works include the unfinished Summa Theologica (1265–1274), Disputed Questions on Truth (1256–1259), and Summa contra Gentiles (1259–1265). Thomas also made significant contributions through his commentaries on Christian Scripture and Aristotle, and he is noted for his Eucharistic hymns, which form part of the Church's liturgy.

Thomas holds the title of Doctor of the Church and is known as the Doctor Angelicus ('Angelic Doctor') and the Doctor Communis ('Universal Doctor'). Pope John Paul II added the title Doctor Humanitatis ('Doctor of Humanity/Humaneness') in 1999.