Saint Thomas Aquinas (1225-March 7, 1274) was an Italian friar of the Dominican Order within the Roman Catholic Church. His influence was felt in philosophy, theology, and law. He was an advocate for natural theology, which employs logic and ordinary experiences in nature to argue for the existence of God. Today, he is honored as a saint, and the Catholic Church holds him as an exemplary teacher for those studying to become priests. Summa Theologica is Thomas' most influential work.