Faith and Reason through Christian History: A Theological Essay by Grant Kaplan (2022, Catholic University of America Press), 336 pages.

In September, Pew released a report considering four possible data-based scenarios, all of which predict a dramatic decline of American Christianity by 2070 with the religiously unaffiliated approaching or exceeding the number of Christians in the United States. Pundits jumped to explain this projected shift, with many blaming the conservative politicization of Christianity in recent decades. Yet according to a 2016 study, for the so-called “nones,” the most common reason they offer for their irreligiosity is not political but intellectual: religion, they say, simply isn’t reasonable.

Of course, secular America is not exactly a champion of meticulous reasoning. It’s true there is a current of anti-intellectualism in some strands of popular American Christianity, but it would require willful ignorance to say this is the only form of Christianity under the sun. As Saint Louis University professor of theology Grant Kaplan articulates in his book Faith and Reason Through Christian History: A Theological Essay, Christians have been contemplating the relationship between faith and reason since the religion’s inception, often in complex if not abstruse ways.

We read in 1 Peter 3:15: “Be prepared to give an account of the hope that is in you.” The emphasis on the correlation between the Greek word logos and Jesus in the prologue to the Gospel of John also represents an early attempt to synthesize the Gospel with Greek philosophy. And the Apostle Paul while in Athens seeks to persuade the Greeks according to the tenets of their own philosophical paradigm. His Areopagus sermon cites respected pagan thinkers Epimenides and Aratus: “For in him we live and move and have our being”; “We are his offspring” (Acts 17:28).

Certain key themes emerge from the professor’s sweeping historical study. The first is that in the premodern era, practically all Christian thinkers (with the exception of a few outliers such as Tertullian) presumed that faith was reasonable and benefited from leveraging pagan philosophical concepts. This stemmed in part from what Kaplan calls a belief that “reason itself was already a graced, supernatural activity in which the human participated in the divine mind.” 

We see this during the patristic age and throughout the medieval period. The Irish monk John Scottis Eriugena (c. 815-c. 880) argued: “What else is the exercise of philosophy but the exposition of the rules of true religion by which the supreme and principal cause of all things, God, is worshiped with humility and rationally searched for?” The English churchman Anselm (c. 1033-1109) coined the phrase “faith seeking understanding” because of his belief that revelation is by its very nature reasonable.

Another attribute of pre-modern Christian thinkers is a humble deference for their intellectual forebears. Thomas Aquinas was prolific in his careful interatction with earlier sources, citing Scripture and church fathers and respectfully engaging with non-Christian thinkers as diverse as Aristotle, Cicero, and the Muslim philosopher Averroes. Aquinas’s confidence in rationality unreliant on revelation is perhaps best evidenced in his Summa Contra Gentiles, which argues on behalf of Christian doctrine based on “unaided human reason.” 

The Reformation presented a challenge to this deference to the past. Luther was severely critical of the Scholastic school in which he was raised and anything else that he perceived as obscuring the preeminent authority of the Bible. “The whole of Aristotle is to theology as darkness is to light (against the scholastic theologians),” reads one of his 95 Theses. That’s not to say Luther and the other Reformers were anti-reason or entirely critical of earlier Christian thinkers—much has been written on the influence of Luther’s nominalist education on his theology. Calvin approvingly cites Augustine and Chrysostom, among other church fathers. 

Nevertheless, whatever one thinks of the necessity of the Protestant project, the Reformation represented a rupture in at least this sense: Luther, Calvin, Zwingli, and their theological descendants assessed that at some point the Christian tradition took a disastrous wrong turn and required an aggressive recalibration to return the faith to its biblical roots. The result of this repudiation was later Protestant generations’ swerving between an increasingly affective and subjective faith suspicious of reason (e.g. the Pietists), a confidently assertive “reason” that limits faith’s value to the realm of ethics (e.g. Immanuel Kant), and even a hostile skepticism of the Bible’s veracity (e.g. 19th century liberal Protestantism).

In contrast to pre-moderns, moderns assumed that intellectual activity occurs autonomously, “without influence or interruption from anything above or outside the mechanistic, natural world.” Of course, one may cite many examples of Christians who rejected this position. Kaplan’s survey focuses most on Catholic examples (John Henry Newman, Maurice Blondel, Erich Przywara) but also includes Protestants (Karl Barth, John Milbank). There are, I should add, other Protestant examples, such as Paul Ricœur or Alvin C. Plantinga.

I can cite only in passing Kaplan’s excellent section on liberationist and counter-traditionalist postmodern theology, a project whose anti-racist, gender-based premises are so absurd that Kaplan’s best attempts at respectful neutrality fail to conceal its deep incoherence. Their mode of criticism “seems to necessitate a wholesale dismissal of almost any canonical account of Christianity,” he bluntly concedes.

Kaplan argues that we should “justly interrogate whether reason can give a full account of itself, on its own terms and with the aid of its own powers.” In other words, reason fails to answer many of the questions and yearnings that indelibly reside within the human intellect and heart. As C.S. Lewis says: “If I find in myself desires which nothing in this world can satisfy, the only logical explanation is that I was made for another world.”

In our faithless era, we have been catechized to perceive ourselves as autonomous individuals who are free from the oppressive, patriarchal strictures of our forebears and even from nature itself. Our contemporaries call this ideology “reason” and “progress,” but really their doctrine is just as superstitious, parochial, and intolerant as the most anti-intellectual communities of Christian history.

This progressive prejudice against our ancestors, though presented as liberating, is actually a debilitating and self-defeating straitjacket. When we jettison such great religious thinkers as Augustine, Aquinas, Pascal, or Newman, we disavow not only reason, but redemptive, transcendent, divine faith. As Kaplan sagaciously ends his survey: “For reason can never be separated from the God who gives the gift of faith so that humanity can be united with that God in both heart and intellect.”