Saint Thomas Aquinas (1225-1274) was a Catholic Priest in the Dominican Order and one of the most important Medieval philosophers and theologians. He was immensely influenced by scholasticism and Aristotle and known for his synthesis of the two aforementioned traditions. Although he wrote many works of philosophy and theology throughout his life, his most influential work is the Summa Theologica which consists of three parts.
The first part is on God. In it, he gives five proofs for God’s existence as well as an explication of His attributes. He argues for the actuality and in corporeality of God as the unmoved mover and describes how God moves through His thinking and willing.
The second part is on Ethics. Thomas argues for a variation of the Aristotelian Virtue Ethics. However, unlike Aristotle, he argues for a connection between the virtuous man and God by explaining how the virtuous act is one towards the blessedness of the Beatific Vision (beata visio).
The last part of the Summa is on Christ and was unfinished when Thomas died. In it, he shows how Christ not only offers salvation, but represents and protects humanity on Earth and in Heaven. This part also briefly discusses the sacraments and eschatology. The Summa remains the most influential of Thomas’s works and is mostly what will be discussed in this overview of his philosophy.