From Pope St. John Paul II’s encyclical Fides et Ratio (1984):
From the teaching of the two Vatican Councils there also emerges a genuinely novel consideration for philosophical learning. Revelation has set within history a point of reference which cannot be ignored if the mystery of human life is to be known. Yet this knowledge refers back constantly to the mystery of God which the human mind cannot exhaust but can only receive and embrace in faith. Between these two poles, reason has its own specific field in which it can enquire and understand, restricted only by its finiteness before the infinite mystery of God.
Revelation therefore introduces into our history a universal and ultimate truth which stirs the human mind to ceaseless effort; indeed, it impels reason continually to extend the range of its knowledge until it senses that it has done all in its power, leaving no stone unturned. To assist our reflection on this point we have one of the most fruitful and important minds in human history, a point of reference for both philosophy and theology: Saint Anselm. In his Proslogion, the Archbishop of Canterbury puts it this way: “Thinking of this problem frequently and intently, at times it seemed I was ready to grasp what I was seeking; at other times it eluded my thought completely, until finally, despairing of being able to find it, I wanted to abandon the search for something which was impossible to find. I wanted to rid myself of that thought because, by filling my mind, it distracted me from other problems from which I could gain some profit; but it would then present itself with ever greater insistence . . . Woe is me, one of the poor children of Eve, far from God, what did I set out to do and what have I accomplished? What was I aiming for and how far have I got? What did I aspire to and what did I long for? . . . O Lord, you are not only that than which nothing greater can be conceived (non solum es quo maius cogitari nequit), but you are greater than all that can be conceived (quiddam maius quam cogitari possit) . . . If you were not such, something greater than you could be thought, but this is impossible”.20
20 Prœmium and Nos. 1, 15: Patrologiæ Cursus completus, Series Latina 158, 223-224; 226; 235.
— Fides et Ratio 14