Aquinas's conception of reason is in some way parallel with his conception of revelation.
Transferred to the divine activity, Aquinas's doctrine led him to insist upon the perseitas boni.
Newman, for whom he worked, helping in the translation of Thomas Aquinas's Catena Aurea, and writing in the British Critic and Christian Remembrances.
Especially is that honour due to St Thomas Aquinas's larger Summa Theologiae.
In the sense in which the term has come to be used by ages that have inherited Aquinas's thoughts.
Again, Western theology, very roughly summarized, while accepting the earlier doctrinal tradition, has broken new ground for itself, in affirming as rational necessity that God must punish sin (this is at least latent in Aquinas's - doctrine of natural law), but as contingent fact of revelation that God has in Christ combined the punishment of sin with the salvation of sinners; this is the Reformation or postReformation thought.
Aquinas's Summa has no such clear lines of division.