No doctrine can be a proper object of our faith which it is not more reasonable to believe than to reject. […] In receiving therefore the most mysterious doctrines of revelation, the ultimate appeal is to reason: not to determine whether she could have discovered these truths; not to declare whether considered in themselves they appear probable; but to decide whether it is not more reasonable to believe what God speaks, than to confide in our own crude and feeble conceptions.
Evidences of the Authenticity, Inspiration and Canonical Authority of the Holy Scriptures (Philadelphia: Presbyterian Board of Publication, 1836), Ch. I: The Right Use of Reason in Religion, pp. 10–11.