Thomas Aquinas (1225-1274), one of the most influential thinkers of all time, was a medieval theologian, philosopher, professor, priest, poet, adviser to popes and kings-and apologist. Because he is considered a doctor of the Roman Catholic Church, his influence has at times been largely limited to Catholic circles. In recent decades, however, there has been a revival of interest in Aquinas's thoughts, among Protestant philosophers and apologists as well as among secular thinkers.
Some theologians have criticized Aquinas for dividing faith and reason and thus unwittingly planting the seeds of modern religious irrationalism. Yet most Aquinas scholars see this as a misunderstanding of his thought, which actually emphasizes the opposite-the unity of truth, knowledge, faith, and reason. Apologists can learn much from Aquinas in both attitude and approach.
Aquinas wrote over 100 titles on a wide variety of subjects. Only a few were specifically apologetic works, the best known being Summa Contra Gentiles, which was written to equip Christian missionaries evangelizing Muslims. However, all that Aquinas wrote was broadly apologetic. His vision was to think out a fully Christian worldview, in all of its aspects, and to articulate and defend it rationally against alternative views.
In his writing Aquinas considered some 10,000 objections against his own positions. He knew what others believed and why they believed it, especially the most influential views of his day. He treated these other positions accurately and fairly, and he responded with gracious but rigorous reasoning and argument. Above all he was interested in truth. (In this regard he appealed to Pr 27:17, saying that "iron sharpens iron.") He had no room for apologetic arguments that used cheap shots, caricatures, or shoddy reasoning, which are unfair and unloving to people and do not serve the truth.
Some of Aquinas's opponents appeared to hold to a two-truth view, believing in truth arrived at by philosophical reasoning and religious truth arrived at by faith. To them, these truths were independent and could be incompatible with each other. Aquinas passionately opposed this wedge between faith and reason as being incoherent, destructive, and unbiblical. Since God is the Creator of all that exists apart from Himself, all truth-however and wherever it is discovered-is from God. It is unified and consistent and ultimately points back to God Himself. Aquinas was ready to accept genuine truths discovered by non-Christian (Jewish, Muslim, pagan Greek) thinkers, and he sought to show them to be ultimately rooted in and best explained within a Christian worldview.
According to Aquinas, some truths about God (e.g., that God exists) can be known by anyone who carefully reflects on the natural order, while other truths about God (e.g., that He is triune) are known only because God has disclosed them to humanity by special revelation. But all of these are truths-they correspond to reality (who God really is and what He really is like). Although the latter truths cannot be philosophically demonstrated from nature, for Aquinas they can and should be rationally defended against objections to their truth. Truth is unified, knowable, and defensible, which makes apologetics both possible and crucial.
Aquinas did not deny the distorting effects of the fall on human thinking, but he emphasized that the fallen creation is a fallen creation. That is, fallen creation still bears the rational and moral marks of its Creator, and it still reflects, though in marred form, His creative intentions. Because all people are created in the image of God and live in a God-created world, believers and unbelievers share considerable common ground. And on that basis we can articulate reasons to believe in God that non-Christians are able to grasp, thus building bridges for the gospel.
Extracted from the Apologetics Study Bible.