Catholic Culture Overview
Catholic Culture Overview

Critical Thinking for Christians

by Peter Kreeft


In this essay on critical thinking, Peter Kreeft answers seven questions: what is "critical thinking"; where does it ultimately come from; how should it order our thoughts; how should it order our actions; how should it order our world; how should it order our spiritual warfare and finally, how will it order our Heavenly victory and peace after this warfare is accomplished.

Larger Work

Envoy Magazine


17 - 24

Publisher & Date

The Institute of Belmont Abbey College, July/August/September 2009

I have been asked to write about the importance of critical thinking, and I’m sure Envoy’s editor meant me to talk about critical thinking not just as an academic exercise or professional game but as a divinely designed tool for ordering our thoughts, our actions, our world, and our task of being working organs in Christ’s Body, His hands and feet for building His Kingdom, His empire – in other words for our jihad, our holy spiritual war.

I think we need to know seven things about ‘critical thinking’:

First, what is it?
Second, where does it ultimately come from? How is it God’s gift?
Third, how should it order our thoughts?
Fourth, how should it order our actions?
Fifth, how should it order our world?
Sixth, how should it order our spiritual warfare?
And finally, how will it order our Heavenly victory and peace after this warfare is accomplished?

First, what is critical thinking? If we answer this question well, we can answer the other six questions very quickly and easily because we will know what we are talking ab out. If not, not.

Critical thinking is more than just thinking critically in the sense of criticizing others’ thoughts, or our own, by finding one or more of the three things that can go wrong with thoughts: ambiguities, falsehoods, or fallacies. Critical thinking means judgment and evaluation but it does not mean only negative evaluation.

Another word for “critical thinking” is “logical thinking.” This is a high and holy thing, in fact a very Christian thing because the ultimate foundation of logic is the Logos, the eternal Mind or Reason or Inner Word of God, which John’s Gospel identifies as the pre-incarnate Christ. The human art and science of logic is the instrument that teaches us to rightly order and structure our thoughts, as a means to the end of thought, which is truth.

One of the most useful aspects of that ordering and structuring is the realization that all the things that can ever go wrong with any thoughts come under just these three headings: ambiguous terms, false premises, or logical fallacies. And this is a wonderful simplifying and clarifying of the process of criticizing any thoughts, written or spoken, by any person, yourself or another, about any topic, human or divine.

"Critical thinking" is simply the currently fashionable term for what used to be called "human reason." It means judging thoughts, negatively or positively, by these three standards, but it also includes at least four more things:

First, it includes generating thoughts, or creating thoughts. Man cannot create matter, like God, but he can create thoughts. What is usually called "creative thinking" in schools today is unjustifiably limited to creating new and original thoughts, which are usually shallow and foolish thoughts because most of us are shallow and foolish thinkers. In fact we are so shallow and foolish that we think that we are deep and wise, and we think that the new and original thoughts we have are better than the old and traditional thoughts of the past, which are the "tried and true" "cream of the crop" of thoughts from thousands of deeper and wiser minds than ours, thoughts that have been tested by time and by millions of other human beings, and which have survived the tsunami of forgetfulness that obliterates most of the memories of each generation, thoughts that have been judged precious and preserved by tradition. As Dorothy Sayers brilliantly pointed out long ago in Creed or Chaos, echoing G.K. Chesterton's Orthodoxy, Christian orthodoxy is the most truly creative and dramatic thought in the world, while every heresy comes from a lack of creativity. Hell has a very limited imagination. Contrast the limited imagination of the demon who tempts you to tediously repeat your besetting sin with the creative imagination of the Creator of the Big Bang, the quark, the Venus flytrap, the ostrich, and Monty Python.

But all this is, alas, incomprehensible to the National Teachers Association, which is one of the two infallible magisteria we have on earth, and every Catholic educator should be grateful to God for them, for they have a 100% error rate, as Rome has a 100% truth rate. The second thing that critical thinking also includes is continuing thoughts rightly once they are created, following a thought as you would follow a deer through a forest. It takes much more moral virtue to follow a thought, virtues like courage and patience and persistence, than merely to generate a thought in the first place, because generating a thought is largely passive, easy, and delightful while pursuing a thought is active, hard, and onerous. The first is inspiration, the second is perspiration.

Socrates was a great example of these virtues of courage, patience, and persistence in following a thought. He never abandoned his quest for the answer to the Delphic oracle's impossible puzzle of "know thyself," and even though he made some crucial errors in his solution to it, such as reincarnation, which he called "a likely story," and the ignoring of the body. Yet his persistence on this quest was the primary origin of Western philosophy, which is perhaps the second most beautiful flower that has ever grown in the soil of Western civilization, after Christianity.

Great philosophers are persistent, or in plainer language, stubborn. Augustine was stubborn, and ruthlessly honest, and fanatically intolerant of logical and personal error, and therefore he succeeded in breaking through a thousand intellectual and moral obstacles to become the second most influential Christian of all time, after St. Paul. Aquinas was stubborn. At age 4 he asked his teacher "What is God?" and because his teacher could not answer him, he eventually wrote the Summa Theologica. If you want to read a good book, sometimes you first have to write it yourself.

Even good atheists and agnostics can be great philosophers if they are stubborn. Camus was stubbornly honest, and had he lived, he might have become another Dostoyevski or Tolstoi. Heidegger was stubborn. All his long life and throughout his long winding trail of thinking and writing, he thought about nothing except being – he would not let the question go – and that is why he became, not the best, but probably the most important, philosopher of the 20th century.

Third, critical thinking also includes insisting on thinking consistently, which means daring to think two premises together and draw the logically necessary conclusion. This is the fundamental form of logical thinking, the syllogism. There is nothing uncreative about a syllogism. It is so creative, in fact, that it is very much like sexual intercourse, in that it produces a product, a thought-child, if we do not artificially contracept it by erecting a barrier between the premises and their conclusion, which we usually do, especially when we fear that the conclusion, like a baby, would be inconvenient to us.

For instance, it is almost universally admitted that these two premises are true but the conclusion is usually resisted: first, that there is a psycho- somatic unity to the human essence and, secondly, that our bodies, which are half of our essence, are masculine or feminine innately, not just by social convention. But rarely is the conclusion drawn that the other half of our essence, our souls, are therefore also innately, and not just conventionally, masculine or feminine. But it is logical. If body and soul are related as matter and form, it is no more possible to change one without changing the other than it is to change the words of a book without changing the meaning, or to change the meaning without changing the words. For they are also related as matter and form.

Here is another, closely related example: if this conclusion about innate masculinity or femininity of souls, in turn, is joined with the additional premise that our whole human identity will be preserved rather than lost in Heaven, that grace perfects nature rather than bypassing it, then I think we will derive some very daring but interesting conclusions about sexuality in Heaven, or at least we will dare to ask the question, dare to think about our two greatest passions together – sex and sanctity – which is something few modern theologians do. (John Paul II is the shining exception with his "theology of the body."). But to do this involves following the path of logical thinking to its end, not just beginning to follow it. It means letting the river of logic take the raft of your thoughts wherever it will take them rather than where you will take them (which is usually only where the Zeitgeist will take them, the social fashions and ideologies that have unconsciously formed your thoughts).

This aspect of critical thinking, drawing conclusions logically from your thoughts, involves not only seeing these logical consequences with the intellect but also acknowledging them with the will. And that requires moral as well as intellectual virtue, for it requires slaying the attractively disguised dragons of sloth which lurk next to each hard and unexpected turn taken by the path of thought. Sloth means not just any kind of laziness but the refusal to exert oneself when in the presence of a spiritual good; and it is a spiritual good to seek and find the truth, to follow the path of thinking, even when it is dark, to the light at the end of that tunnel; to think through a thought thoroughly; to do as good a job and build as sound a building with thoughts as we do with bricks or steel.

A fourth element of critical thinking is applying conclusions rightly in the practical order, letting our thought make a difference to our life, translating principles into practice. The single most crucial instance of this is one that is embarrassing to all of us, and worse than embarrassing. If we are Christians we all admit that the only way to true happiness is sanctity, not sin. We know this truth not only by faith but also by reason and by repeated experience. Everyone seeks deep, true, lasting happiness, and only the saints find it. Yet we are not saints. Every time we sin, we suffer, yet we keep sinning. Every time we overcome sin, we have deep joy, yet we keep refusing joy. God keeps offering us joy in His right hand and misery in His left, and we keep saying, "Duh, I think I'll try the left hand." We are, in other words, quite simply, insane. That's one of the meanings of Original Sin. If we only lived logically, we would all be saints. Instead, we think illogically and uncritically. We keep uncritically falling for the Devil's advertisements, eating the worms on his fish hooks. We desperately hope that there is some other way to happiness than God's way, even though no one has ever found it. That is not critical thinking!

For instance, every morning we are faced with our first choice of the day: do we give our first thoughts to God, do we take that first thought captive and bring it to the feet of our Lord, or do we claim it for ourselves and use it to gratify our own way to happiness, whatever we think that is? Do we yield our brain to the thousand tiny soldiers that run at it across the battlefields of waking consciousness, who threaten it with their tiny swords of worry thoughts and planning thoughts and “my will be done” thoughts? Or do we mercilessly murder those little bastards from Hell by the authority and power of the God who is a consuming fire, and trust ourselves and our day to Him? Do we think: I am going to be so busy today that I have no time to pray? Or do we think: I am going to be so busy today that I must begin my day with prayer, because if I do not give Christ the meager loaves and fishes of my time, they will not be multiplied and at the end of the day I will be frazzled and frizzled like hair in a hurricane? Usually, we selfishly eat these loaves and fishes ourselves, fearing any diminution of them if we give them to the One who alone can multiply them and always does, if we give them up – which we well know from repeated experience. We all know the results of these two experiments: every single day of our lives we have performed one or the other of them, and the results have never varied. Yet we insist on singing Sinatra's song "I Did It My Way" instead of "God's Way is the Best Way" day after day, even though Sinatra's song is the song they all sing as they enter Hell, while the other one is the one they all sing on the way to Heaven.

This fourth aspect of critical thinking – its practical application – is of course the most important one of all because it makes the biggest difference to our lives. In fact "important" may fairly be defined as "making a difference to your life." Buddha knew the life-changing importance of critical thinking better than most of us do. The very first and best known line of the best known and best loved Buddhist book, the Dhammapada, says:

"All that we are is determined by our thoughts;
it begins where our thoughts begin,
it moves where our thoughts move,
it ends where our thoughts end."

This is even more crucial to a Christian, who knows that the end of the road is not just temporal but eternal happiness or misery. As one obscure writer has reminded us:

"Sow a thought, reap an act;
Sow an act, reap a habit;
Sow a habit, reap a character;
Sow a character, reap a destiny."

Buddha was right: "all that we are is determined by our thoughts."

So for a Christian, critical thinking means not only thinking that has been purged of illogic but also of sin; not only thinking that has been subjected to the honest judgment of the theoretical reason, but also to the honest judgment of the practical reason, or reason about practice, i.e. moral reason.

The judgment of the theoretical reason consists in these three logical questions: (1) what does it mean? (2) is it true? and (3) what is the evidence or proof? In other words, are there any ambiguous terms, are there any false premises, and are there any logical fallacies? If not, the conclusion is true.

The judgment of the practical, moral reason consists in a single question: is this good or evil? A crucial difference between the judgment of the theoretical reason and the judgment of the practical reason is that the judgment of the practical reason is almost always clear, and immediate, and certain. We know what is good and what is evil far more clearly than we know what is true and false. Our conscience is louder than our logic. Most problems of discerning God's will are moral, not intellectual. Jesus Himself said, when asked by the Pharisees how they could understand His teaching, "If your will were to do the will of my Father, you would understand my teaching." That is the most important principle of critical thinking about morality.

My first point is finished: what I mean by "critical thinking." Over half our work is over.

My second point is that reason, or critical thinking, comes from God. It is God's gift.

But how can that be true if it is something we do and something we are responsible for? God does not do our critical thinking for us.

It is God's gift for two reasons. First, because it is the exercise of an essential part of the image of God in us. God does not think our thoughts for us, yet our minds are dependent on God's mind just as totally as the existence of  the physical universe is dependent on God’s will to “let it be” and on God’s power to do all that He wills. Our minds are mirrors, and God is the sun, and all the light we generate is reflected light from Him; yet it is our choice to turn our mirrors to the sun or not, and to keep them clean or not, and to keep them unbroken or to break them into fragments. Every time we think wrongly, we misuse a divine gift, just as whenever we misuse our free will we misuse a divine gift. Both wrong thinking and wrong choosing are sacrileges, because they desecrate a holy thing. What we pervert in wrong thinking is the mirrored powers of God's own mind that He gave us in giving us His own image. We pervert this image whenever we move our minds into the dark and away from the light, just as we pervert the mirrored powers of God's will which He gave us in giving us free will as part of His image in us, whenever we move our wills to evil and away from good. God continues to uphold in existence His spiritual gifts, the two powers of His image in us, even when we pervert them, just as He continues to uphold the physical universe even when we misuse it. At the moment when He said "Be" in creating the universe, he said "continue to be" to Cain's rock even as it split Abel's head, and to the nails we used to pierce His own Son's flesh on the Cross.

The second reason critical thinking is God's gift is because grace perfects nature, and this is an essential part of human nature, the ability and the desire to think logically as a means to thinking truly.

The fact that grace perfects nature means that the very same things that are truly ours, and come from our own human nature and activity, can be truly God's, and from the actions of His grace. (This principle, by the way, is the central and simple key to reconciling free will and predestination: what is divinely predestined is precisely our truly free choices.)

My third, fourth, and fifth points will be very short because we all know the answer to them pretty well.

The third question is: How should critical thinking order our thoughts? And my answer is: Unconscious  time but by conscious decision sometimes, especially those times when it is hardest and we are most tempted to laziness.

There are many other good ways of thinking than thinking logically –thinking intuitively or mystically or imaginatively or romantically or even sometimes randomly – and there are many occasions when we should think non-logically, but there are never times when we should think illogically, except when we are deliberately making a joke, laughing at laughable follies. But our lives should not be laughable follies.

Thus the answer to this third question, how critical thinking should order our thoughts, is also the answer to the fourth question, how it should order our actions. For "Sow a thought, reap an act." It takes the will, not the mind, to carry out the thought into the act, and between the thought and the act lies many a shadow. But that is a topic for another day, when we talk about moral vices and virtues.

We should "live according to reason," said the ancient Greeks, meaning not that we should be computers rather than human beings, but that we should be human beings rather than animals. Reason is not limited to logic, though logic is one of the things that sharply distinguish human reason from animal consciousness. The meaning of that great old word "Reason" was arbitrarily narrowed to "calculation" beginning with Descartes and the Enlightenment (which I prefer to call the Endarkenment) and with the restriction of all approved thinking to what can be proved by the scientific method – which, of course, is self-contradictory since that very principle cannot be proved by the scientific method! Confusing life with a laboratory is not what it means to live according to reason. Moral conscience, aesthetic appreciation, intelligent, responsible religious faith, intuitive wisdom, and even mystical experience are all part of the powers of human reason in the broad old honorable Greek sense of the word. Sometimes I think half the world’s problems would be solved if the whole world had to speak ancient Greek. It would be like Pentecost: an undoing of the Tower of Babel.

And the fifth question, how critical thinking should order our secular world, is simply an extension of the fourth question, how it should order our individual lives, for the life of the world is simply the coming together of all our individual lives.

Just think for a moment what a radical revolution it would be if the whole world practiced just one basic virtue of thought, the virtue of honesty – not just honesty with each other but honesty with yourself and with the truth.

The world does not lack the knowledge of solutions to its problems; almost any one of the basic virtues –justice, charity, gratitude, compassion, wisdom, honesty – if practiced, would transform the world from a vale of tears to a palace of joys. How to attain this Utopian dream? There is a very simple way: one person at a time. You have only an appallingly tiny control over whether others join this radical revolution, but you have an appallingly large control, and responsibility, over whether you do. Start working for world peace and justice and understanding. Start inside the walls of your house.

The sixth question is: How should critical thinking order our jihad, our spiritual warfare? We are soldiers of the King, and the purpose of our life on earth is to work and fight for His kingdom. We are at war with the enemies of peace, because He is. He told us that: "I came not to bring peace but a sword." His kingdom is a Kingdom of peace. He wants us to make peace with the three parties we are at war with: neighbor and self and God; and therefore His Kingdom is at war with the world, the flesh, and the devil, who are at war with neighbor, self, and God. If we are Christians, we fight; but if we are Christians we fight with weapons like poverty and chastity and obedience, for we fight against enemies like greed and lust and pride. Now how is critical thinking a weapon in this war?

The enemy in this war is Satan and his fallen angels, of course – unless our Lord, His Church, and His Book are all fools or liars. As you know if you have read C.S. Lewis's masterful expose of the enemy's strategy called The Screwtape Letters, the enemy's two strongest strategies are: Dim the Lights and Divide and Conquer. "Dim the Lights" means "Don't let them think clearly and honestly." "Divide and Conquer" means "Make them hate and resent and mistrust each other and wrestle against each other rather than against the principalities and powers of darkness in high places." Thus "Divide and conquer" also depends on "Dim the lights" for it means "Confuse them about who their enemy really is." No medical operation can be carried out without light, and no military operation can either. No matter how powerful an army is, if it is blind, it will lose. A blind Cyclops will lose to a clever Ulysses. A blind Christian will lose to a clever devil.

One form of blindness that is very hard for us to detect in ourselves is a skewered perspective, majoring in minors, missing forests for trees. A shining example of a man who is trying to restore a right perspective today is Pope Benedict, especially in his recent Regensburg address, which from the perspective of the destiny of Western civilization is perhaps the most important speech since Alexandr Solzhenitsyn's 1978 Harvard Commencement Address. Benedict does not see Islamic terrorists as the primary problem in today's world. They are only a symptom of a deeper issue in the Islamic world: is Allah a God of reason or of force? Is Heto be worshipped because He is powerful or because He is good? Christianity gave a sharp and unmistakable answer to that question, on Calvary. If Islam gives the same answer, or something like the same answer, something close to the same answer, then we invite them to join us in an ecumenical jihad, a common spiritual warfare in the name of our common God against our common enemy, which is modern Western atheism, secularism, and relativism, the apostasy and rebellion against that God on the part of the nations of the West that made up the civilization that used to be called Christendom.

To have that kind of clear perspective is like being a lookout on the “Titanic,” or the little boy in “The Emperor’s New Clothes.” It certainly deserves the title “critical thinking” because it is thinking rightly about crisis.

Many more things could be said, but I will end soon, with my last point, the eschatological or Heavenly dimension of critiical thinking, because I want to give you time to digest this. For it seems to me that that is the highest purpose of communication: to stimulate thought, which naturally expresses itself in questions and dialog. Talks are monologs. Dialogs are better. In fact, monologs exist for the sake of dialogs. The nature of ultimate reality is not monolog but dialog: it is called the Trinity. I have always thought of talks as something like diving boards and dialog afterward as something like swimming pools, and I am impatient with speakers who act like they have squatter's rights on diving boards. As you are probably now impatient with this article that is taking  many minutes to end, rather than just ending!

What will critical thinking be in Heaven? Will it be part of the Beatific Vision? Or will it be a kind of comic relief from the Beatific Vision? I really don't know, but here is my guess. I think the Beatific Vision is much more ordinary-looking than we think. I think Jesus had it all the time, until it was taken away in that moment of Hell on the Cross when He said, "My God, My God, why hast Thou forsaken Me?" [Ed. note: Here we could wish Kreeft expressed himself more clearly. As you read on, you'll see that he is not saying that the Beatific Vision is "ordinary", but suggesting that possessing it does not necessary produce astonishing exterior manifestations, such that we would not be able to interact with others in what we might loosely describe as an ordinary way. This also explains his reference to Christ Who, in fact, did have the beatific vision in His human nature by virtue of the hypostatic union of His human and divine natures (the Church teaches this), and Who could still interact with others in an ordinary human way. So true is this, in fact, that we must also beware of saying that Christ lost the beatific vision at any time, since this would suggest that the hypostatic union had been broken, which would mean that Christ ceased to be Christ, the God-man, one Divine person with two natures. So again we must excuse Kreeft for writing a little loosely. Here we must understand him to be suggesting that Our Lord may have permitted His human nature to fail to feel the consolations of the Beatific Vision, as presumably also happened when He sweat blood through a psycho-somatic dread of His coming ordeal in His Agony in the Garden. There is a good deal of mystery here, and this is not Kreeft's central topic. Given Kreeft's stellar commitment to Catholic orthodoxy in all his writings, it is only fair to interpret these almost off-hand remarks in an orthodox sense.] I think the saints in Heaven have the Beatific Vision all the time yet nevertheless can converse with us without haloes, without fits of distraction, and without losing the ability to make a joke. I think that, because that's what Jesus was like. He was fully human, remember, as well as fully divine at the same time: "like us in all things save sin." Jesus was not a mystic; or, if He was, He was a mystic and a perfectly ordinary man at the same time, so ordinary that most men missed His divinity. The greatest saint of the worst century in history, Mother Teresa, was totally ordinary: earthy as the earth, humble as humus, grounded as a grandmother. And her mind was like a small, sharp kitchen knife. It cut instantly through layers of baloney.

Do you want to see what critical thinking looks like? Read everything Mother Teresa ever said. And read John Paul the Great. And Augustine, and Aquinas. Complete, Heavenly critical thinking, the thing we are training for here, has all four of those dimensions at once, Like Jesus Himself. It is as profoundly logical as Aquinas, and as profoundly practical as Mother Teresa, and as profoundly visionary as John Paul II. I suggest these four models for your imitation and as your training for critical thinking on earth and in Heaven.

Dr. Peter Kreeft is the author of nearly 50 books. When he is not writing books, he somehow finds the time to be a professor of philosophy at Boston College.

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