So, the revealed truth of God both requires and stimulates the believer’s reason. On the one hand, the truth of the Word of God must be considered and probed by the believer – thus begins the intellectus fidei, the form taken here below by the believer’s desire to see God. Its aim is not at all to replace faith, rather it unfolds naturally from the believer’s act of faith, and it can indeed assist those whose faith may be wavering in the face of hostility. The fruit of the believer’s rational reflection is an understanding of the truths of faith. By the use of reason, the believer grasps the profound connections between the different stages in the history of salvation and also between the various mysteries of faith which illuminate one another. On the other hand, faith stimulates reason itself and stretches its limits. Reason is stirred to explore paths which of itself it would not even have suspected it could take. This encounter with the Word of God leaves reason enriched, because it discovers new and unsuspected horizons. Fides et Ratio 73.
of the "Sanctus Benedictus Patronus Europae" Rome, 25 November 2011