Summa contra Gentiles

The Summa contra Gentiles is one of the best-known treatises by Thomas Aquinas, written as four books between 1259 and 1265. Whereas the Summa Theologiæ was written to explain the Christian faith to theology students, the Summa contra Gentiles is more apologetic in tone. While the last of the four books (parts) of the S.C.G. deals with topics of revealed theology such as trinity, incarnation, and the sacraments, the first three books limit themselves to natural theology: arguments on the basis of reason, Thomas believes, will be understood also by those who do not believe in Christian revelation.