Is faith rational?

That question animates the lifelong work of Frederick D. Aquino, Edward and Emma Lehman Chair of Christian Doctrine at Perkins School of Theology.

As a young man, Aquino questioned whether religious belief could be rationally justified. Skeptical, he drifted from the Christian faith for a time.

But those questions eventually brought Aquino back to faith – and set him on a lifelong scholarly path that began in an SMU classroom and, decades later, would take him to the Vatican.

As Aquino began to grasp the complexity of that seemingly simple question – Is faith rational? – other questions followed:

Could faith be reasonable, even when beliefs are not supported by conclusive evidence?

Do human beings actually demand that kind of evidence for most of the important judgments they make?

Or might faith and reason work together as ways of knowing?

A pivotal moment came while Aquino was a doctoral student in Religious Studies at SMU. He enrolled in a course exploring faith and reason in the Anglican tradition, taught by the late William “Billy” J. Abraham, longtime Perkins professor and noted theologian and philosopher. In that class, Aquino discovered John Henry Newman’s University Sermons.

“That was a turning point,” he said. “Newman’s compelling way of thinking about faith and reason captivated me then, and I’m still captivated.” 

Discovering Newman 

Newman – the 19th-century Anglican leader who became a Roman Catholic cardinal – rejected both hard rationalism that treats formal proof as the only reliable route to knowledge and fideism (“faith alone”) that essentially separates faith from reason.

Instead, Newman proposed that religious belief can meet reasonable standards of justification much as judgments in ordinary life typically do. He highlights the ways in which implicit reasoning factors into the formation of religious and non-religious beliefs. In everyday life, people rely on “antecedent probabilities” – expectations shaped by what they have observed in the past – as part of a reasonable process of belief formation. So, human reasoning involves evidence, but also experience, judgment, emotion, conscience, prior assumptions and the accumulated knowledge of the whole person. Aquino found Newman’s more nuanced understanding compelling.

That first paper grew into Aquino’s dissertation and ultimately his first book, Communities of Informed Judgment: Newman’s Illative Sense and Accounts of Rationality published in 2004. And that initial discovery blossomed into an academic vocation.

In the decades that followed, Aquino’s work distinguished him as an internationally recognized scholar of Newman. He has written and edited numerous books and articles examining Newman’s thought and its implications for contemporary questions in philosophy, theology and religious epistemology. His scholarship has taken him to universities including Oxford, Notre Dame, Pontifical Urbaniana, Pepperdine and Georgetown, where he has been invited to lecture on Newman.

As a professor at a United Methodist theology school and someone personally rooted in the Church of Christ tradition, Aquino often receives invitations to conferences and ecumenical conversations with leading thinkers from other traditions. 

From SMU to the Vatican

In 2025, Aquino’s decades of scholarship also led him to a place he never envisioned as a doctoral student: the Vatican.

Aquino was among 20 international scholars invited to contribute to the Positio, the theological document considered by cardinals and bishops as part of the process that led to Pope Leo XIV’s decision to confer the title of Doctor of the Universal Church on St. John Henry Newman. Aquino, widely recognized for his scholarship on Newman’s epistemology, was one of only two non-Catholic contributors.

The details of his behind-the-scenes contribution remain confidential, as is customary with the Positio. But the invitation itself reflected the reach of a body of scholarship that began with Aquino’s questions about faith and reason during his days as a student at SMU. 

A deepening conversation

Newman’s designation as a Doctor of the Church has brought renewed attention to his thought – and Aquino continues to explore its contemporary implications.¹

His forthcoming book, John Henry Newman’s Humane Epistemology, co-authored with Logan P. Gage of Franciscan University of Steubenville, explores Newman’s understanding of how people arrive at reasonable beliefs.

“Newman’s ‘humane epistemology’ takes seriously not only evidence and argument, but also emotions, personal formation and the education of the whole person,” Aquino said. “Acknowledging those influences on reasoning can provide a richer understanding of how people actually think, judge and come to know.”

Aquino believes Newman’s ideas can also inform ecumenical dialogue. His article, “Cultivating an Ecumenical Habit of Mind: A Newmanian Proposal,” explores how Newman’s concept of a “connected view” – learning to see how things fit together in light of one another – might help Christians engage thoughtfully across traditions. 

Broadening the conversation

Many assume faith and reason are diametrically opposed habits of mind, Aquino said, “But Newman offers us a third way. He had some very fresh, creative and expansive ways of thinking about the relationship between having faith and being rational. That can be illuminating both to people of faith and to skeptics.”

Aquino is working to bring those ideas into broader conversations. As director of Perkins’ William J. Abraham Lecture Series, Aquino invites thinkers from across disciplines and perspectives – including believers, nonbelievers and atheists – for conversations about faith, knowledge and reason.

In his own congregation, Preston Road Church of Christ, Aquino teaches a weekly class for laypeople who are wrestling with their own beliefs. There, the questions Aquino studies academically become questions of lived faith as class members wrestle with belief, doubt and what it means to believe reasonably.

It’s common to view faith and reason as competitors – that one begins where the other ends, or that choosing one means surrendering the other. Aquino’s decades of engagement with Newman point toward a more expansive possibility: that rationality is richer than formal proof, that faith can be examined critically and reasonably, and that life’s largest questions are best answered by bringing different ways of thinking into conversation. It is an answer Aquino is still exploring — to the question that first captivated him as a young man: Is faith rational? 

¹ For example, Frederick D. Aquino and Joseph Milburn (eds.), John Henry Newman and Contemporary Philosophy (Routledge, 2025).