Summa Theologica - 01 Pars Prima, Initial Questions Quotes

“Objection 2: Further, if it is a matter of argument, the argument is either from authority or from reason. If it is from authority, it seems unbefitting its dignity, for the proof from authority is the weakest form of proof. But if it is from reason, this is unbefitting its end, because, according to Gregory (Hom. 26), "faith has no merit in those things of which human reason brings its own experience." Therefore sacred doctrine is not a matter of argument.”
― Thomas Aquinas, Summa Theologica - 01 Pars Prima, Initial Questions