Summa Theologica - Part I Q84b-87: How the Soul While United - How the Intellectual Soul Knows Itself and All Within Itself

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)

 84. How the Soul While United to the Body Understands Corporeal Things beneath It

 85. Of the Mode and Order of Understanding

 86. What Our Intellect Knows in Material Things

 87. How the Intellectual Soul Knows Itself and All Within Itself