St. Thomas Aquinas
St. Thomas Aquinas (1224/5 – 74) offered his Five Ways, or five proofs for the existence of God, near the beginning of his magnum opus , the Summa theologiae (Part 1, Question 2, Article 3, the response). The Summa (ST), as it is often called, was written as a textbook for men in their priestly formation. It is well over 2,500 pages in a standard English translation from the Latin, but the Five Ways take up only slightly more than one page. Nevertheless, they are almost assuredly the most commented on section of the Summa and some of the most well - known arguments for the existence of God.
M. Bruce & S. Barbone (Eds.), Just the arguments: 100 of the most important arguments in western philosophy.