ABSTRACT
It might be expected that Thomas Aquinas's thought about faith is well understood. It is laid out in three discussions in his major works and has been studied extensively over the past 30 years. This chapter focuses on the discussion in the Summa, the so-called Treatise on Faith, because it is the last and the richest of the discussions and prominently links faith to the gifts of understanding and knowledge. On a 'naturalistic' reading, Aquinas thinks that there are arguments of sufficient credibility not only to prove that God exists, but to move one intellectually to embrace Christian faith. According to 'voluntarist' interpretations, Aquinas makes it clear that potential believers, lacking sufficient evidence, must will their assent to the Christian mysteries. In this way, Aquinas distinguishes between faithful and unfaithful (in Aquinas's terms, heretical) believing about God. The distinguishing mark seems not to be only what is believed about God, but rather how the beliefs are determined.
