The other great philosopher of the medieval era was Thomas Aquinas. Aquinas was an Italian philosopher-theologian. He was the most influential thinker of the medieval period. He produced a powerful philosophical synthesis that combined Aristotelian and neo-Platonic elements within a Christian context.
He is said to have done so in an ingenious and original fashion. He was both an outstanding philosopher and a theologian. The major part of his work is theological in nature. However, as will be seen later, Aquinas distinguished between strictly philosophical investigation and inquiry and theological investigation and inquiry.
His philosophy was based on the light of natural reason and his theology presupposes faith in divine revelation. He argued for a complimentarity between the discipline and truths of philosophy and theology. He concluded that it is impossible for there to exist a contradiction between philosophical truth and theological truth since all truth is God's and God's truth is rational or reasonable. If one of these disciplines is false, then we are forced to attribute falsity to God and God is never the source of falsity.
Methodologically, Aquinas proposed that in the discipline of theology one reason from belief in God and his revelation to the implications of this for created reality. In philosophy one begins with an investigation of created reality insofar as this can be understood by human reason and then seeks to arrive at some knowledge of divine reality viewed as the cause of created reality and the end or goal of one's philosophical inquiry.
Aquinas wrote a more technical style of philosophical/theological work and his great works are also twofold: Summa Contra Gentiles and Summa Theologia.
