“This is great stuff!” the friend sitting next to me said, smacking the top of the bar to emphasize the point, which summoned the bartender over to ask if we wanted another round. My friend explained that he’d been talking about a book, but yes, now that you’re here we’ll have another.

An Old Testament scholar, he’d been raving about St. Augustine’s de Magistro and Augustine’s profound answers to questions about truth he was pursuing. Indeed, Augustine asked questions he had not known to ask. He said he had found himself, not by conscious intention and a little to his surprise, reading more and more of the classics—even, though he’s an Evangelical, St. Thomas—and fewer and fewer contemporary books. The old books answered the questions he was asking much better than the modern ones.

A man so excited about reading Augustine is a great thing. My friend, though very accomplished in his own field, turned to Augustine not as a subject but as a teacher. As he talked, I thought of several articles I’d read recently, written for Francis’ visit to the United States, delivered with supreme confidence, and to someone who knows the subject products of almost perfect ignorance, sometimes mixed with malice.

The contrast between my learned friend and the unlearned writers made me think of a lesson most of us who think about things miss because we’re too busy trying to say something: We know a lot less than we think we do because we’re not very good knowers. This is especially true for writers and teachers because man naturally assumes that he must be very good at something he has to do all the time, especially if people pay him for it.

We don't easily see the truth because of who we are. The factors affecting our insight include our age (personal) and age (general), culture, religious convictions, class, race, ethnicity, sex, political commitments and entanglements, the binding force of church, family, friendships, and other relations in which we're enmeshed, the demands of our employers, our moral acts and our spiritual lives, our humility and pride, and the grace of God, who gives to some understanding but not to others. As St. Paul noted, we see as in a mirror darkly, but the fault is not so much the glass as our eyes.

C. S. Lewis got at this in "On Reading Old Books,” which first appeared as the introduction to a translation of St. Athanasius’ On the Incarnation. “We may be sure,” he wrote, “that the characteristic blindness of the twentieth century—the blindness about which posterity will ask, ‘But how could they have thought that?’—lies where we have never suspected it, and concerns something about which there is untroubled agreement between Hitler and President Roosevelt.”

We can see this, to take an easy example, in the ways the abolitionists assumed the inferiority of black people in a way that today would ruin the career of the most conservative Republican candidate. They were enlightened for their day, but their day had its limits.

We are corrupted, inadequate instruments, but that’s not the only problem. We often don’t see the truth because the truth takes work to see. Deep study of any subject shows how elusive the truth can be. One person convinces you and then the next un-convinces you. Study often reveals to you how little you actually know and how much that you thought you knew you don’t really understand. You find that to understand the subject you’re interested in you have to understand subjects you never thought of studying.

As the Dominican A. G. Sertillanges wrote in his wonderful book The Intellectual Life (and yes, that’s a recommendation): “The athletes of the mind, like those of the playing field, must be prepared for privations, long training, a sometimes superhuman tenacity. We must give ourselves from the heart, if truth is to give itself to us. Truth serves only its slaves.”

But though most people know that man doesn't easily see the truth because of who he is, few of us incorporate this insight into our thinking, and our thinking about our thinking. We are different people when reflecting on our humanity and when sitting at the computer writing. (That “we” may be too inclusive, but it describes me and the great majority of writers and scholars I know. Not all of them know it.)

The vocation of Christians who follow the issues and read sites like this one is to discern the truth and especially the truths we don't easily see. There are two things to do, I think, to fight our natural inclinations and to see better than we do.

First is immersing ourselves in the Catholic tradition, especially the Magisterial documents, and to submit to the tradition as a guide and director, as a father and teacher, and not use it as a collection of proof texts selected for their value in supporting your favored causes. Doing this is harder than it sounds. Those of us who aren’t professional theologians have to read these works when we’d rather read something else.

More challenging, our normal mode of reading is to judge what we read through our prior commitments and to use what we read as evidence for positions we already hold. Which is not wrong, exactly. A Catholic can’t read a relativist utilitarian as if he might be right about the value of killing of disabled newborns. But we've submitted ourselves to the Church and her teaching for good reason. This are works to read as authorities, as the freshman physics major reads the Nobel Prize winner. The rule is: sympathy first, only then (if really necessary) criticism.

Second is to read less that makes us comfortable in our ideas and to read more that challenges us. Lewis explained the reason: No one can completely escape the blindness he described, “but we shall certainly increase it, and weaken our guard against it, if we read only modern books. Where they are true they will give us truths which we half knew already. Where they are false they will aggravate the error with which we are already dangerously ill.”

He goes on to make his famous argument for reading old books. We don’t read them because “there is any magic about the past,” he wrote.

People were no cleverer then than they are now; they made as many mistakes as we. But not the same mistakes. They will not flatter us in the errors we are already committing; and their own errors, being now open and palpable, will not endanger us. Two heads are better than one, not because either is infallible, but because they are unlikely to go wrong in the same direction. To be sure, the books of the future would be just as good a corrective as the books of the past, but unfortunately we cannot get at them.

He suggested reading an old book after reading a new book, or at least to read one old book for every three new books you read. I would extend this to reading one substantial book you will disagree with—preferably a classic of its sort—to every two or three you agree with, and to read them with as much sympathy as you can manage. If, for example, your economics leans left, read Friedrich Hayek’s The Road to Serfdom. If your economics leans right, read Karl Polanyi’s The Great Transformation. Rarely will such a book change your mind, but it should make you understand your position more subtly, particularly to see its limits and its failings in a way you would not have done on your own, and it should help you to see more clearly why others disagree with you.

Many of us could be better knowers than we are. The early pagans said of the Christians, “See how they love one another.” We could do more to make the modern secularists say of us, “See how they love the truth.”