Summa Theologica - Part I Q77-79a: Of Those Things Which Belong to the Powers of the Soul in General - Of the Intellectual Powers

The Summa Theologica (or the Summa Theologiae or simply the Summa, written 1265–1274) is the most famous work of Thomas Aquinas although it was never finished. It was intended as a manual for beginners as a compilation of all of the main theological teachings of that time. It summarizes the reasonings for almost all points of Christian theology in the West, which, before the Protestant Reformation, subsisted solely in the Roman Catholic Church. The Summa's topics follow a cycle: the existence of God, God's creation, Man, Man's purpose, Christ, the Sacraments, and back to God. (Summary adapted from the Wikipedia)

77. Of Those Things Which Belong to the Powers of the Soul in General

 78. Of the Specific Powers of the Soul

 79. Of the Intellectual Powers