The great crisis of faith for me came—as it does for so many—when I was in college. I arrived at the University of Virginia in 2001 as a bored atheist. I neither believed in God nor particularly cared about religion. I was, however, a very enthusiastic pre-law student, certain that I would major in political science, attend a great law school, and presumably get rich suing people.

Two events early in college changed the course of my life. First, I accidentally took an ethics course in my freshman year. It was love at first argument. I took some more classes, and soon found out that other branches of philosophy were even more interesting. By my sophomore year, I had declared a second major in philosophy. After a particularly awful pre-law summer program, I switched to philosophy as my primary major. Then my academic advisor told me that if I really liked philosophy, I could go to graduate school and eventually make a living writing and teaching it. That settled it. I never looked back.

That was the first big decision; then came the second. While in college, I became Catholic. I went to church for the first time on the first anniversary of the September 11 attacks. I didn’t have much of an idea what a weekday Catholic Mass entailed, but there was a church near my dorm, and for some reason I had it in my head that since it was the anniversary of the attacks, they would do some kind of special memorial. I was feeling very down thinking about all of the senseless death at the World Trade Center, and I wanted to talk to someone with moral gravitas about it. Church seemed liked a place where this would happen.

So I went to Mass, and it was very much an ordinary weekday Mass—no speeches, or 9/11 memorials, or anything. Instead it was me, the priest, four old ladies, one short reading, a lot of prayers I didn’t understand, and a Communion that I happily had the inner wherewithal not to participate in. When I left, I remember thinking, “Well, that wasn’t what I expected.” But something about the experience felt absolutely right. I started going back during the week. Then I started going on Sundays. I began to pray. During my third year of college, I was received into the Church. At each step it felt exactly right—like God was leading me, like I could trust the people sharing the faith with me, like worshipping God was something I was meant to do.

At the time, the decisions to become a philosopher and to become Catholic had absolutely nothing to do with each other, other than the fact that they were major life decisions I was making behind my parents’ backs. But as time passed, the two parts of my life—the philosophical part and the faith part—began to conflict. While I was in the process of joining the Church, I was very secretive about my Catholicism. I was a philosopher, to be sure, and I loved to argue. But I was very worried about having to defend my newfound faith to others.

And you have to admit, there are some hard questions for Christianity. You really believe that there is a being in heaven who knows all of our innermost thoughts and sees the future? You think his son (who happens also to be him) came to earth, turned water into wine, died, and then came back from the dead—and somehow his death and coming back is centrally important to repairing all of the evils in the world? If you take a step back, some of this sounds a little crazy. It gets much worse when you consider the problem of evil: If God really exists, and he is really all powerful, and really morally perfect, then why do so many horrible, senseless things happen? The magnitude of evil in the world seems like excellent evidence against God’s existence. Matters get still more difficult when you add in some of the more striking Catholic elements of the Christian faith—transubstantiation, Mariology, papal infallibility . . . Faith just did not seem philosophically respectable to me. So I treated it like my bad Sunday habit and worried that, when it came to what mattered most in my life, I was in fact a very unreasonable person.

I think this was the wrong conclusion to draw, and I want to talk about why. First we should ask: Why does there seem to be a struggle between faith and reason? Here is where I think the struggle originates. Many faiths are thick; that is, having the faith means not only loving and trusting in God but also believing a complex and rich set of historical, theological, philosophical, and moral claims. Catholics like myself believe historical claims, such as that Jesus died and was resurrected. We believe theological claims, such as that Jesus is God and so is the Holy Spirit. We believe philosophical claims, such as that it is possible for God to be three persons but just one God. And we believe moral claims, such as that we owe extraordinary allegiance to God.

Thick faiths like Catholicism are in tension with reason because of their complexity; other evidence might conflict with claims from the faith. For example, we might have a difficult time finding appropriate historical evidence for claims about Jesus’s life. Our best logic might seem to show that doctrines like the Trinity are contradictory, because nothing can be both one and three simultaneously. Our best moral theories might seem to entail that nothing could justify God’s having created a world with so much evil in it.

Suppose you find yourself with such a thick faith. What should you do when an important teaching of your faith conflicts with a historical, philosophical, or moral fact that you also feel very confident in? That’s the struggle. And it is a struggle anyone with a sufficiently thick faith must be prepared for.

There are at least four approaches you might take to resolve such struggles when they arise. First, you might take what I call the Way of Dilution and give up those parts of your faith that conflict with the other evidence. Second, you might take the Way of Fundamentalism and give up belief in any facts that conflict with components of your faith. Third, you might take the Way of Separation and insist that faith and reason are fundamentally different kinds of belief with different roles in our lives. They do not need to agree, and in fact we should keep them separate. Finally, you might take what I call the Way of Aporia, that is, insist that there is a tension between some claims of faith and reason, that the two cannot be separated, but that nevertheless there is not enough reason to give up beliefs on either end.

According to the Way of Dilution, when reason conflicts with something you took to be an article of faith, you should rethink the supposed article of faith. And sometimes this is advisable. We make mistakes. We misunderstand. There is evidence of this in the stories of Jesus’s early disciples. At the Ascension, they thought Christ would return quickly. It turned out they were wrong. The early Church struggled to understand what God meant when he said he would return, and over time they were forced to adjust their assumptions. This kind of thinking is surely appropriate, and we should all be open-minded and scrupulous about the best way to interpret difficult parts of our faith in light of new evidence.

But it is also very easy to take this strategy too far. A colleague of mine, Gary Gutting, published an article in the New York Times this past Easter arguing that the core of the Catholic faith is a commitment to an ethics of love, and that the historical teachings of the faith are best taken as useful parables. Gutting does not think it incumbent on a Catholic to believe anything in particular about history or metaphysics. He writes:

The ethics of love I revere as the inspiration for so many (Catholics and others) who have led exemplary moral lives. . . . As to the theistic metaphysics, I’m agnostic about it taken literally, but see it as a superb intellectual construction that provides a fruitful context for understanding how our religious and moral experiences are tied to the ethics of love. The historical stories, I maintain, are best taken as parables illustrating moral and metaphysical teachings.

But if Catholicism is nothing more than one manifestation of an “ethics of love,” then there is no non-arbitrary reason to be Catholic (rather than, say, a secular humanist). It is also not obvious that we can preserve the Christian sense of love while kicking away the metaphysical and theological ladder. Love, in the Christian faith at least, is not just love for one’s fellow man. It is, most centrally, about love for God. But how can you love someone unless you know about him? And how could you possibly love God without having beliefs about what he is like, what he has done in history, and why he is worthy of love?

John Updike has a beautiful poem called “Seven Stanzas at Easter” where he chides Christians who want to treat Jesus’s death and Resurrection mostly as a moral parable rather than as an actual historical event. He writes:

The stone is rolled back, not papier-mâché,
not a stone in a story,
but the vast rock of materiality that in the slow
     grinding of
     time will eclipse for each of us
the wide light of day. . . .

Let us not seek to make it less monstrous,
for our own convenience, our own sense of beauty,
lest, awakened in one unthinkable hour, we are
     by the miracle,
and crushed by remonstrance.

Truly grasping the uncontroversial parts of our faith (such as God’s love) often means struggling to grip the more complicated and controversial parts (like the historical Resurrection). Dilute too much, and you are likely to find you’ve also lost the core of the teachings you originally valued.

So much for the Way of Dilution. Another option is to go the Way of Fundamentalism—if important doctrines of your faith conflict with reason, dismiss or radically reinterpret the evidence from reason. This, I submit, is a horrible idea. The main problem with the Way of Fundamentalism is that if you decide carte blanche that there are doctrines of faith that cannot be scrutinized by reason, you risk making huge mistakes about your faith.

Venerable systems of belief tell us that reason is a very good faculty. St. Paul gives us deeply moving arguments in defense of our need for reason in the life of faith. In the first chapter of Romans, he diagnoses why so many of his contemporaries had fallen into the grip of myths and cults. Their trouble, he says, is that God gave them reason to guide them to the complex truths of faith, but they abused and disregarded this gift. In his characteristically poetic style, he tells us, “Although they claimed to be wise, they became fools and exchanged the glory of the immortal God for images made to look like a mortal human being and birds and animals and reptiles.” Cults ask you to accept their teachings either without reason or despite reason. And Paul reminds us that cultic faith, like diluted faith, is just not faith worth having. Indeed, the same faculty that enables us to distinguish between good and bad science helps us in the complicated task of distinguishing between trustworthy and dubious religious teachings.

So as we have seen, when faith and reason struggle, it is a bad policy always to favor one side over the other. What else, then, should we do? A third option—one I call the Way of Separation—insists that matters of faith and matters of reason should be kept separate. According to this strategy, evidence from history, moral philosophy, logic, and so on simply has nothing to do with whether or not certain doctrines of faith are true. Faith and reason are separate magisteria, any apparent contradiction is merely apparent, and we shouldn’t feel pressure to resolve our views one way or the other. For example, logic can show that the doctrine of the Trinity is inconsistent, while it remains a central teaching of our faith. The Way of Separation advises us to accept both while maintaining that the two beliefs are not genuinely contradictory. On the Way of Separation, we treat faith and reason the same way that parents treat warring siblings on long road trips: You sit on this side, and you sit on that side, and please— for the love of God—try not to hit each other!

Teaching philosophy at Notre Dame, I often hear from my students that they favor this approach. And perhaps in some sense it is better than the Ways of Dilution or Fundamentalism, because at least it tries to preserve the core commitments of a thick faith alongside our best evidence from history, logic, ethics, and so on. Still, I think the Way of Separation fails.

For one thing, as we saw in the case of the early disciples, it is important that reason and faith communicate so we don’t make grave mistakes when it comes to understanding the requirements of our faith. For another, the Way of Separation assumes we can sharply distinguish the reasons for our religious faith from other, more ordinary sorts of reasons. But it isn’t at all clear that we can. According to one way of understanding faith, it is just belief in something without any evidence. If this is what faith is, then obviously faith is distinct from reason. The New Atheists, thinkers like Richard Dawkins, insist that this is how we should define faith. Dawkins uses this definition to argue that a Christian worldview is inherently unscientific, since the core of a scientific worldview is an insistence on reasons.

But as someone with a thick faith, I think this is wrong. For every complex religious, scientific, moral, or philosophical belief that I have, there seems to be some reason or other that partially supports it. And these reasons come from a variety of sources. I believe that the sun will rise in the east tomorrow, because, given all the data about previous sunrises, it is the prediction with the most inductive support. I believe that kicking puppies for fun is morally wrong because I believe that puppies feel pain and that it is wrong to cause sentient creatures pain for fun. I believe God exists, because I think he is one part of the best explanation for the order in the universe, because I have considered and trust the testimony of other believers, and because I think there are times in my life when I have perceived God’s presence.

These are all reasons, if not perfectly decisive ones. Are all of the reasons purely “from faith”? It is hard to say—some come from perception, some come from philosophical and scientific observation, some come just from believing observations others have made. Even the mysteries of faith are mysteries not because they are believed with no reason whatsoever, but rather because we depend on God to reveal the evidence of these mysteries to us. In other words, there is reason for mysteries, just not the kind of reasons we can get to under our own epistemic steam. Religious faith, like every other part of our cognitive lives, always looks for reasons, and reasons come from many sources. Doubt can be so crippling because we are ruthless reason seekers.

If, as I would argue, the above three ways of resolving struggles between faith and reason are dead ends, is there any other option? I think there is, and I will call it, borrowing the term from Aristotle, the Way of Aporia. Aporia is an intractable philosophical puzzle—a puzzle in which you believe every premise of an argument, but there is no way they could all be true. Aporia is also a state that you get yourself into when you face a seeming paradox. Aristotle and many philosophers since have been deeply interested in the question of what you should rationally do if you find yourself facing such a puzzle.

Aporetic problems come up in mathematics and physics. For example, currently our best formal logic (the foundation for our best mathematics) is provably incomplete. In short, this means that we know we will never be able to make several components of our best mathematical logic agree with each other. This was one of the earth-shattering discoveries in philosophy of the last century, arrived at primarily by a logician named Kurt Gödel. But though we know our logic is incomplete, we don’t know which assumption is causing the problem. All of the assumptions appear to be truths of logic—individually they look impeccable.

So what should we do? It would be crazy to stop using logic and mathematics just because we discovered this deep bug. And it would also be irrational just to arbitrarily pick one assumption in our logic and reject it. Rather, the rational thing to do is to admit that some part of our understanding of logic is flawed, keep looking for a good reason to reinterpret one or another part of the system, remain worried (deeply worried!) about the conflict, but also—and here is the crucial part—keep using logic. After all, logic and mathematics are very good. We need them. And we still don’t have any clue as to what a better system would be. The only way to repair logic is from the inside—to keep expanding our understanding until we find the source of conflict.

And we see a similar case in physics. Our best theory of space and time—general relativity—seems inconsistent with quantum mechanics. It would be deeply foolish at this juncture to declare one branch of physics correct and the other mistaken. Both are well supported. The only way out of the puzzle is to do more physics.

The Way of Aporia in faith is, I suggest, very similar. A faithful person finds himself in a situation where some part of his thick faith seems to conflict with other evidence. He really believes the core teachings of his faith are true, and with good reason: Perhaps he trusts authoritative texts, the teachings are the best explanation of his religious experience, or the teachings help him to make sense of some important aspect of the world. He also really believes some conflicting claim from history, ethics, science, or logic. Something has gone wrong. He should not just arbitrarily pick which claim to believe and which one to reject. The best thing to do is admit that some part of his understanding is flawed (he doesn’t know which), that he needs to keep working to resolve the conflict, and that it is rationally acceptable to go on believing both until he finds a way to break the stalemate.

Sometimes we do figure out where we made a wrong turn. And there are some conflicts that we never get to resolve in this life. At the heart of the Way of Aporia is a conviction that you shouldn’t ignore conflicts between faith and reason. They are bound to happen, especially if you have a valuable, thick faith. But you also should not give up important beliefs too quickly or too flippantly in the face of conflict. This is a perfectly respectable stance in other branches of inquiry. And it is perfectly respectable for Christians to assume.

We get a strong suggestion from the Gospel about the right way to handle struggles between faith and reason. Just think about Mary. When Mary was told she would give birth to Jesus, she thought it made no sense given her circumstances. Luke reports that even after Jesus was born and the shepherds came to worship him, Mary was astonished at what was happening. But rather than rashly conclude that either her understanding of biology was wrong or her understanding of theology was wrong, the Bible tells us that she “treasured up all of these things and pondered them in her heart.” That is to say, she didn’t back away from her astonishment, and she didn’t rashly settle on one conclusion or another; she held themall together and pondered them. For this reason she is rightly called the Seat of Wisdom. I think we could do worse than emulate Mary when we try to tackle the very real conflicts between faith and reason in our own lives.

Meghan Sullivan is the Rev. John A. O’Brien Assistant Professor of Philosophy at the University of Notre Dame. 

Articles by Meghan Sullivan