Saint Thomas Aquinas. Portrait of Saint Thomas Aquinas (1225-74), Italian philosopher. In his teachings, Saint (St.) Thomas combined his own thought with those of previous scholars such as Aristotle, Avicenna and Averroes. He taught that there was no conflict between scientific reason and religious faith. Some things could only be known through faith, some through reason and others, including God, by both faith and reason. He also claimed that as humans sought truth, they bring themselves closer to an understanding of God. A major influence in philosophical thought, St. Thomas' work made scientific enquiry in the Christian world more respectable.