Thomas was a proponent of natural theology and the father of a school of thought encompassing both theology and philosophy known as Thomism. Central to his thought was the doctrine of natural law , which he argued was accessible to human reason and grounded in the very nature of human beings, providing a basis for understanding individual rights and moral duties.
Thomas's best-known works are the unfinished Summa Theologica , or Summa Theologiae — , the Disputed Questions on Truth — and the Summa contra Gentiles — His commentaries on Christian Scripture and on Aristotle also form an important part of his body of work. He is also notable for his Eucharistic hymns, which form a part of the Church's liturgy.
As a Doctor of the Church , Thomas Aquinas is considered one of the Catholic Church's greatest theologians and philosophers. Thomas Aquinas was most likely born in the family castle of Roccasecca , [ 20 ] near Aquino , controlled at that time by the Kingdom of Sicily in present-day Lazio , Italy , c. While the rest of the family's sons pursued military careers, [ 24 ] the family intended for Thomas to follow his uncle into the abbacy; [ 25 ] this would have been a normal career path for a younger son of Southern Italian nobility.
At the age of five Thomas began his early education at Monte Cassino, but after the military conflict between Emperor Frederick II and Pope Gregory IX spilt into the abbey in early , Landulf and Theodora had Thomas enrolled at the studium generale university established by Frederick in Naples. Julian, a Dominican preacher in Naples, who was part of the active effort by the Dominican Order to recruit devout followers.
At the age of nineteen, Thomas resolved to join the Dominican Order. His change of heart, however, did not please his family. Thomas was held prisoner for almost one year in the family castles at Monte San Giovanni and Roccasecca in an attempt to prevent him from assuming the Dominican habit and to push him into renouncing his new aspiration. Family members became desperate to dissuade Thomas, who remained determined to join the Dominicans.
