Grace and Reason According to St. Paul and St. Thomas

…the world we live in is overwhelmingly irrational. Our popular discourse doesn’t make any sense at all. As Catholics, we need to understand what our faith teaches about this irrationality. We need to look to Scripture and tradition.

St. Paul and St. Thomas Aquinas

A recent week’s politics left Catholics reeling. The Supreme Court says there is no reason but bare animus to believe that marriage between a man and a woman is different from any other relationship—the most basic biology is treated like the most bizarre doctrine of faith.

The mass media acclaim a woman in Texas who, aided by a screaming mob, thwarted a measure supported by two-thirds of the people of the state. The “extreme” measure prevents abortion only after twenty weeks, and requires that abortionists have faculties to admit a hemorrhaging woman into the hospital.

And the mass media jeer the governor of Texas for pointing out that the woman who filibustered the bill is herself a beautiful exemplar of why we should count no life as hopeless. She was the daughter of an uneducated single mother, and then herself an uneducated single mother—but went on to be first in her college class, then a graduate of Harvard Law School, and now a state senator, before acquiring this new, dubious claim to fame.

In short, the world we live in is overwhelmingly irrational. Our popular discourse doesn’t make any sense at all. As Catholics, we need to understand what our faith teaches about this irrationality. We need to look to Scripture and tradition.

We often feel torn in two directions. We are tempted to wash our hands of the world. There is sometimes talk, even gleeful, that America, and maybe the world, is coming to an end. We will be persecuted. We can never win the public debate. We look forward to an age of martyrdom.  There is no hope.

But we are also tempted in the opposite direction. We cannot give up on this world, so perhaps we should just learn to speak their language. If they believe everything is about individual rights, we will go along, at least for the sake of argument. If they think our viewpoint is an irrational doctrine of faith, we will go along, and claim basic justice is a matter of religious liberty. If they don’t believe in God, we will argue as if God does not exist—and so a new theory of natural law is popular (almost completely unrelated, we must add, to the old theory) in which “natural law” means we will pretend we don’t think there is a God, or that his existence is irrelevant to the moral life and public policy.

We find ourselves thinking that the only way to engage the argument is to accept our opponent’s basic premises about how the world works. A nagging suspicion makes us wonder whether we are selling our birthright for a pot of beans. Individualism makes motherhood, marriage, community, and the Church absurd. We oppose gay marriage, abortion, and a lot of other things because we are not individualists. Fideism—the idea that everything is a matter of faith—denies the wisdom of the Creator, and the dignity of man.

And to pretend there is no God? What is the point? If we won every other argument, but conceded the nonexistence, or irrelevance, of God, what would we be left with?

We can do better than these twin temptations. But we must look back to the sources: to the Bible, and to our great theologians.

We should all know that according to Thomas Aquinas, grace builds on nature, and faith is consistent with reason: faith teaches some things we could know by our own powers, but often don’t, and other things we could never know without it. Sometimes, if our philosophy professors have been more enthusiastic about Thomas than our theology professors, we forget that Thomas also says grace is necessary to heal our wounded nature, and make us rational again.

Thomas’s point is entirely biblical. Read carefully through the first chapter of Paul’s letter to the Romans. And don’t forget that Paul is writing to the Church in pagan Rome: not so different from our own situation.

In fact, Paul makes this issue of rationality the starting point for his most important articulation of Christianity. He wants to make a point about morality. He begins, “I am not ashamed of the Gospel of Christ, for it is the power of God unto salvation to everyone that believes; to the Jew first, and also to the Greek. For therein is the righteousness of God, revealed from faith to faith: as it is written, the just shall live by faith” (vv. 16-17).

The topic is righteousness, or justice (the same word in Greek). And Paul’s first point is that we come to it through faith. This is the seed of truth in the fideist temptation to wash our hands of this foolish world, and expect to lose every public argument. But what he says is that faith in the Gospel of Christ brings us salvation. Salvation from what?

His argument then takes a surprising turn. He says that the ungodly and unrighteous “hold the truth in unrighteousness” (v. 18). The unrighteous, in some sense, already possess the truth. How?

He is going to discuss morality, but first he discusses theology. He says, “that which may be known of God is manifest in them; for God has showed it to them. For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse” (vv. 19-20).

The First Vatican Council insisted, paradoxically, that Catholics are bound to believe that the existence of God can be known by reason alone. We are tempted to forget this, though Pope John Paul II urgently reminded us in Fides et Ratio: reason works. Reason can climb all the way to God. On some level, says St. Paul, there is “no excuse” for failing to know, not only moral truth, but even the truth about God: his “invisible things,” his “eternal power and Godhead.” Whatever that may mean, it’s pretty high up.

Paul explains the situation of unbelievers: “when they knew God, they glorified him not as God, neither were they thankful” (v. 21a). The root of the problem is gratitude, thankfulness. The Greek word is, of course, eucharistia. According to Paul, the very heart of the problem is that we do not give thanks to God.

We may pause already and notice: what is the problem with abortion and gay marriage?  Do they not spring, at their deepest roots, from ingratitude toward the Creator? We can argue until we are blue in the face about the humanity of the unborn, or the need to preserve traditional marriage, but those who see creation itself as a cruel joke are unlikely to see why they should care; whereas those who know the Good God cannot imagine why they would not care.

But notice, too: Paul thinks there is no excuse for not giving thanks. Reason knows there is a God, knows everything good comes from him. But sin refuses to give thanks.

The situation of fallen man is strange. Those who are ungrateful to God, Paul says, “became vain in their imaginations, and their foolish heart was darkened. Professing themselves to be wise, they became fools” (vv. 21b-22). Don’t we know it! “They changed the truth of God into a lie, and worshipped and served the creature more than the Creator, who is blessed forever. Amen” (v. 25). (Notice that Paul can’t even talk about this without himself blessing God: eucharistia.)

The problem is complicated. On the one hand, they know, and have no excuse. On the other hand, their foolish hearts are darkened. Fallen man stands in a strange middle ground between a rationality that remains, in one sense, robust enough that they are “without excuse.” Indeed, robust enough that an eternity with no hope of knowing God would be Hell; and, in another sense, so depraved that they can really live as if God did not exist.

The next stage in Paul’s argument moves from the speculative, or religious aspect, knowledge of God, to practical, or moral, questions. In fact, his rhetoric is a little confusing, because the one issue bleeds into the other. Verses 23-26 talk about both.

First, he says they “changed the glory of the incorruptible God into an image made like to corruptible man, and to birds, and four-footed beasts, and creeping things” (v. 23).  Now, on one level he is talking about genuine pagan idolatry: worshipping a statute of a bird. This seems a little irrelevant, since our contemporaries do not practice idolatry in such a direct way.

But the point is actually quite deep—Paul has real insight into ancient paganism. Why do they make images of these things and worship them? Precisely because they think these things represent what is most important. Our contemporaries do not literally worship images of political figures, but they certainly do put those images in the place of God. Although moderns are not as honest as the ancients and, thus, don’t dramatize their worship of sexuality, for example, with the symbol of a snake or a cow, they certainly show they are replacing God with earthly things through many graphic images.

Like the Egyptian mysteries popular in Paul’s Rome, moderns see a kind of paradoxical liberation from the supposed drudgery of being human in an embrace of animal irrationality.  “God therefore,” says Paul, “also gave them up to uncleanness through the lusts of their own hearts, to dishonor their own bodies between themselves” (v. 24, cf. 26a). Is this a punishment from God? Not exactly. It’s more like this: once we give up on rationality, and the God to whom reason ineluctably leads us, we become irrational, and are left with nothing but lust.

What is most striking here is that in Paul’s telling, God is not the most distant accomplishment of reason, not some add-on to the moral life, and certainly not an obscure doctrine of faith. God is the most rational thing of all. The problem is that once you give up on God, you have given up on rationality all together, and there is nothing left.

Now, that is a difficult situation. Their minds are profoundly darkened by their lusts, and their denials of rationality. It is not like we can just sit down one afternoon with the Summa, and prove to them that obviously there’s a God. The Fall leaves us too committed to the irrationality of lust for that. And Thomas is insistent (against many of his contemporaries, including other doctors of the Church), that God’s existence isn’t exactly obvious: it’s not the first thing we know, anyway, but just the conclusion that ought to be obvious from everything else we know.  His “five ways” shows that everything about the rationality of the world points us to God.

We should see the connections. The moral life is rooted in gratitude to God. And conversely, those whose moral life is rooted in rejecting God cannot easily accept his reality. Admitting the existence of God, admitting even the rationality of the world, would change everything.

Therefore, Thomas begins the second part of his Summa, on morality, by arguing that there is no happiness apart from God: our hearts are restless until they rest in him. And the second part of the second part—on the specifics of the moral life—begins with faith, then hope and charity, before it ever gets to prudence, justice, fortitude, and temperance. In Thomas’s thinking, you can’t make a serious argument without in some way keeping God in the picture.  Aristotle gets to God at the end. But you can’t get anywhere if you refuse ever to go there.

Paul follows the same course. After speaking of “the lusts of their own hearts,”  “dishonoring their own bodies,” and “serving the creature more than the Creator,” Paul talks about the moral life. He begins, in fact, with sexual immorality: “their women changed the natural use into that which is against nature” (v. 26b)—a passage the tradition reads in terms of contraceptive sex, abortion, and other non-procreative sexual activity. Following this passage, they called such things simply “contra naturam.”  Paul immediately relates this to homosexuality: “likewise, also the men, leaving the natural use of the woman, burned in their lust toward one another; men with men working that which is unseemly, and receiving in themselves that recompense of their error which was fitting” (v. 27).  Paul’s situation was not so far from our own: once you deny the nature of sexuality, the consequences are obvious.

But we should read his words carefully. First, notice his emphasis on “nature” and what is “natural.” Paul doesn’t think this needs to be explained. Again, the point would seem to be that natural and unnatural are directly rooted in gratitude and recognition of nature’s God. For Paul, what makes these things wrong, and paradigmatic examples of immorality, is precisely their rejection of creation and the Creator. “And even as they did not like to retain God in their knowledge, God gave them over to a reprobate mind, to do those things which are not right” (v. 28).

The second point, that makes Paul treat sexual sin as a paradigm of all sin, is the burning of lust.  Destroy reason, by refusing to acknowledge God, and you are left with nothing but lust. And given that, the results are obvious.

The third point is that we must keep reading in order to recognize that sexual sin is not the only issue: rather, it is a paradigm of all sin. There follows a tediously long catalog of sins: “all unrighteousness, fornication, wickedness, covetousness, maliciousness; full of envy, murder, debate, deceit, malignity; whisperers, backbiters, haters of God, despiteful, proud, boasters, inventors of evil things, disobedient to parents, without understanding, covenant-breakers, without natural affection, implacable, unmerciful” (vv. 29-31).

At least, in Thomas Aquinas’s reading, Paul has introduced sexual sin not because it is the only sin, but because it helps us see into the nature of all sin. What is wrong with “boasting,” for example? Precisely that it is motivated by a kind of lust, instead of  by gratitude toward God.  These things, too, are unnatural, ignorant of God, and lustful. Sex just makes the dynamic of sin vivid for us.

So he concludes, “Who knowing the judgment of God, that they who commit such things are worthy of death, not only do the same, but have pleasure in them that do them” (v. 32). If we know there is a God, we know that our backbiting, spite, pride, disrespect for parents, and lack of understanding, affection, and mercy are incompatible with eucharistia—thankfulness, which is the very heart of life as a rational being.

So where does this leave us? First, with the Gospel. We recognize that we, too, are sinners. We, too, are irrational, and ungrateful, and driven by our lusts. As Paul will conclude (after considering the parallel case of those who have Revelation but not the Spirit of Christ), “All have sinned and come short of the glory of God” (3:23). And, so we discover in ourselves our need of the Gospel. Without Christ, we are lost. Indeed, what Romans 1 shows us is that, given our darkened intellect and the lusts of our hearts, without Christ we are not even rational, not even human. We remain human enough only to suffer from our distance from the truth.

Second, we realize the necessity of Christ for all. When we look at the irrationality of the public debate, we should not be surprised. This is precisely how Paul sets up the need for the Gospel.  And, as we saw, he precedes all this by saying, “I am not ashamed of the Gospel of Christ: for it is the power of God unto salvation to everyone that believes; to the Jew first, and also to the Greek.”

Romans 1 shows that those without revelation are themselves “without excuse,” yet, so given over to lust as to be hopeless without Christ. Romans 2-3 shows that even with God’s law, we are hopeless without the grace poured out from the Sacred Heart of Jesus and his sacraments.  We rely on the promise (Romans 4). For Christ has died for us (Romans 5), and we are planted by baptism into his death (Romans 6), so that we should live in newness of life (Romans 7) and in his Holy Spirit (Romans 8).

We must not be ashamed of the Gospel. Christ has the power to save. Without his salvation, we are lost. The righteous live by faith, because faith gives us access to the grace which can make us human again, and rational.

Third, we should understand rightly the irrationality of the debate. Once God is excluded, everything else falls apart. We need to respond rightly. On the one hand, we should not be afraid to make reasonable arguments. Reason is on our side. The opposition really is irrational. It is insane to accept the presuppositions of the insane—like arguing with a two-year-old (to which, I am sorry to say, I, too, stoop).

We can make coherent arguments, and we should try to make them fully coherent: not being afraid to include the beauty of family and community, the beauty of motherhood, the beauty of nature, and, where appropriate, the beauty of God. To exclude God from our argumentation on principle is irrational. Though, on the other hand, our arguments don’t come from pure faith.  That marriage is between a man and a woman, that abortion is atrocious: these things are simply rational, and we shouldn’t pretend that we believe them because of religion—we should only acknowledge that those who reject God on principle, end up rejecting rationality. Show them the beauty of Christian rationality.

But at the same time, we should recognize that the world is fallen. That doesn’t mean it is without hope. Indeed, Christ has overcome the world; and we can overcome evil with good. In the end, the Christians conquered Rome. But they conquered in Christ. The irrationality of the debate should precisely remind us that there is no other name, under heaven, by which we might be saved.

Dr. Eric M. Johnston, PhD About Dr. Eric M. Johnston, PhD

Eric M. Johnston is an assistant professor of undergraduate theology at Immaculate Conception Seminary at Seton Hall University, and a father of five. He has published in The Thomist, Nova et Vetera, and Crisis. His research focuses on Thomas Aquinas' approach to nature and grace, marriage, political philosophy, and spirituality. He writes on spirituality at


  1. Avatar Marty Kurlich says:

    You wrote that in Romans 1:18 St. Paul “takes a surprising turn. He says that the ungodly and unrighteous “hold the truth in unrighteousness” (v. 18). The unrighteous, in some sense, already POSSESS the truth.”
    I don’t know if that is the right take on verse 18. The RSV-CE reads “For the wrath of God is revealed from heaven against all ungodliness and wickedness of men who by their wickedness SUPPRESS the truth.”


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  2. […] Grace and Reason According to St. Paul and St. Thomas Eric M. Johnston, Homiletic and Pastoral Review The world we live in is overwhelmingly irrational. Our popular discourse doesn’t make any sense at all. As Catholics, we need to understand what our faith teaches about this irrationality. We need to look to Scripture and tradition. […]