The relationship between science and faith, reason and Revelation, where reason and faith are shown “as the two wings on which the human spirit rises to the contemplation of truth” (Saint John Paul II,  Fides et Ratio ), is a constant source of concern for humankind in its encounter with the sacred. Étienne Gilson (1884–1978) wrote a short and insightful book on this subject,  Reason and Revelation in the Middle Ages  (Rialp, 2025) . It explores the various perspectives from which this dialogue took place in the Middle Ages. This book is a timely resource for helping to untangle the knots we may encounter when trying to harmonize religious experience with its intellectual understanding.

A first response “is comprised of those theologians who believed that Revelation had been given to humankind as a substitute for all other knowledge, including science, ethics, and metaphysics (p. 20).” For them, the Gospel is sufficient, and therefore all speculation is superfluous: Jerusalem has nothing to do with Athens. The fideism that follows from this position and the rejection of the uses of reason are self-evident.

A second family emerges, the Augustinian. Here, the great Fathers of the Church teach “theological doctrines in which the fundamental concordance between natural and revealed knowledge was everywhere, either stated or presupposed. St. Augustine is the most faithful representative of this group (p. 27).” The saint of Hippo argues that if we do not believe, we will not understand. We would be wrong to disregard reason, for the Gospel itself has promised to all who seek the truth in the revealed Word the reward of understanding (cf. p. 29). St. Augustine’s great endeavor was to achieve a Platonic understanding of Christian Revelation.

Along these same lines, Saint Anselm (1033-1109), taking into account that the standard science of his time was logic, developed a rational understanding of the Christian faith. It was Saint Anselm, Gilson points out, who coined the famous formula:  credo ut intelligam  (I believe so that I may understand) (cf. p. 31).

Averroes (1126-1198) also championed reason, the use of which presupposes knowledge of logic. Drawing on Aristotle, Averroes distinguished three kinds of arguments, such that “faith is the only possible approach to rational truth for men of imagination; theology is the closest thing to metaphysics for a purely dialectical mind; but philosophy is absolute truth, as established by the demonstrations of pure reason (p. 44).” As can be seen, the ordinary believer becomes a third-class citizen compared to a select few enlightened individuals.

Saint Thomas Aquinas (1225-1274) sought harmony between reason and Revelation by a different path. Without abandoning understanding, he distinguished those revealed truths necessary for the salvation of humankind from those that transcend all human reality (the Trinity, the Incarnation, and the Redemption). “No philosophical speculation can provide any necessary reason for such a truth; no philosophical conclusion can be deduced from any article of faith, because they are principles believed from equally believed theological consequences, not intelligible principles from demonstrated rational conclusions. However, if reason cannot prove that they are true, neither can it prove that they are false” (p. 66). This harmony is largely broken in modernity, where a theology without philosophy and a philosophy without theology converge (Descartes, Bacon).

We have a yearning for transcendence, as well as a deep desire to understand and find meaning in reality. The mere psychological idea of ​​God is insufficient to give wings to the spirit. What a believer believes is that  God is . At this point, Gilson notes, “we can no longer conceive of God as a mere ‘wholly other’ to whom our a priori category of the ‘mystical’ bears witness; the Son, too, is a witness, and has revealed who the Father is. That is, finally, a Revelation worthy of the name: not our own revelation of God to us, but God’s Revelation to us (p. 75).”