In our conversation about Anselm's Ontological Argument for the existence of God, we talked some about Aquinas. I've since had several people ask me more about who he was and why he was important for us to know about. So, in the coming days we'll discuss some of his contributions to the fields of philosophy and theology. Thomas Aquinas lived and worked in the Middle Ages. In order to understand the Middle Ages you have to wrestle with a world that is vastly different from our own. If you lived in the Middle Ages you would believe that the sun revolved around the earth and that the earth was actually the center of the universe. You would believe that the world was created in six days like it says in the Book of Genesis. You would believe in a "Great Chain of Being", beginning with God and going down through the angels to the lowest forms of plant and animal life with humans as the midpoint between the mortal and the divine. You'd believe that the universe possessed a fixed order; everything has its place. Math governed the circular movement of the heavenly bodies and learning was founded on the classical authors of Greece and Rome.
In the Middle Ages, most of Europe -- certainly Great Britain, France, Germany and Italy -- used Latin as the international language. The two most important and powerful institutions were the Holy Roman Empire and the Roman Catholic Church. The church and the Christian faith controlled every aspect of life.
This was the period that gave birth to universities. The University of Paris grew out of the Cathedral School at Notre Dame and was approved by the Pope in 1215. Universities in Spain and Italy were just getting their starts. Oxford and Cambridge received their first Chancellors. Learning was moving out of the monasteries and into these universities, and philosophy found its natural home there -- becoming less and less exclusively associated with the church.
The Philosophy of this period was known as "Scholasticism" -- because it was taught by scholars rather than religious clergymen. Granted, many of these scholars were religious clergyment, but they viewed themselves through a more scholastic lens as opposed to a monastic lens now.
The greatest of these scholastics was Thomas Aquinas (c. 1225-1274). His philosophy was known as Thomism.