Thomas Aquinas held that reason can defend faith but never prove it

Evidence

Thomas is clear about the limits of the defensive arguments he provides: … First of all I wish to warn you that in the disputations with unbelievers about articles of the faith, you should not try to prove the Faith by necessary reasons. This would belittle the sublimity of the Faith, whose truth exceeds not only human minds but also those of angels; we believe in them only because they are revealed by God. … Yet whatever comes from the Supreme Truth cannot be false, and what is not false cannot be repudiated by any necessary reason. Just as our Faith cannot be proved by necessary reasons, because it exceeds the human mind, so because of its truth it cannot be refuted by any necessary reason. So any Christian disputing about the articles of the Faith should not try to prove the Faith, but defend the Faith. Thus blessed Peter [1 Pet. 3:15] did not say “Always have your proof,” but “your answer ready,” so that reason can show that what the Catholic Faith holds is not false. — John V. Tolan, Saracens, 1229

Categorization

• DEFINE: Defines the distinction between proving the faith and defending it against refutation.
• XREF: connects to: Aquinas denied Islam any authority because it lacked miracles and true documents