Thomas Aquinas was an Italian Dominican friar, philosopher, Catholic priest, and Doctor of the Church. An immensely influential philosopher, theologian, and jurist in the tradition of scholasticism, he is also known within the latter as the Doctor Angelicus and the Doctor Communis.  He was the foremost classical proponent of natural theology and the father of Thomism; of which he argued that reason is found in God.

Thomas Aquinas is considered one of the Catholic Church's greatest theologians and philosophers.  Pope Benedict XV declared: "This (Dominican) Order ... acquired new luster when the Church declared the teaching of Thomas to be her own and that Doctor, honored with the special praises of the Pontiffs, the master and patron of Catholic schools."

Source: https://en.wikipedia.org/wiki/Thomas_Aquinas