Why Christianity is Rational

The Three Arguments that Changed my Mind

Most men now think that religion has nothing to do with rationality. But it’s a Protestant idea that God can be known only by faith. The Catholic Church teaches that natural reason can know with certainty that God exists from the things He has made. Furthermore, natural reason can also demonstrate the immateriality of the intellect. And against the philosophical background of these two facts, the rational case for the Resurrection is overwhelming. Indeed, these were my steps to Catholicism, and I hope this article will help others along the way.

The Uncaused Cause

The argument from causality is one way we can know with certainty that God exists. When I was a teenager, I dismissed it. Only later did I discover that I’d never understood it. “A little philosophy inclines man's mind to atheism,” said Bacon, “but depth in philosophy brings men's minds about to religion.” Unfortunately, even philosophers today tend to have only a little philosophy.

Bertrand Russell is a typical example. In his book Why I Am Not a Christian, he said: "If everything must have a cause, then God must have a cause.” To my uneducated teenage mind, that sounded like a convincing objection. And I presumed a Cambridge philosophy professor knew what he was talking about. But I was wrong. On the topic of religion, otherwise intelligent men often say extremely stupid things because their pride has prevented them from ever taking it seriously.

The argument from causality does not say that everything must have a cause. Instead, it says that everything which does not contain within itself sufficient reason to account for its own existence must have a cause apart from itself. That isn’t hairsplitting; it’s necessary precision. When we look at the universe, we see that it’s finite, changing and contingent. It didn’t have to be the way it is. It didn’t have to be at all. But it exists.

What are we to make of this fact? In his debate with Copleston, Russell called the universe a “brute fact”. It just is, he said, and reason can go no further. To me, that was admitting intellectual defeat. Ironically, given that the people who take this view often claim to do so in the name of “science”, it’s also not scientific. When scientists investigate the world, they ask how things came to be and why they behave as they do. They describe the intelligibility of the world by formulating physical laws.

Science thus assumes the reality of causality and that the universe is rational. That’s why saying that the universe is rational but ultimately lacking a rational explanation struck me as incoherent. Nor can the universe have been the cause of its own existence; otherwise, it would have to exist before itself in order to cause itself. But that’s impossible.

And you appeal to the eternity of matter either. It’s not just that the Big Bang shows the universe did in fact have a definite beginning. The ultimate point is that the duration of something doesn’t explain its existence. “The train has always been running” doesn’t explain the train away. The same principle applies to Einstein’s example of an "oscillating universe” — an indefinite series of expansions and contractions.

When we observe the world around us, we see that every element is dependent and exists in a chain of causality. And since each link of the chain is dependent, so is the entire chain. It’s not really a temporal question at all: it’s about what upholds the universe and everything in it right now. And that can only be God: necessary, self-existent Being.

You can avoid this conclusion only by denying the reality of causality, in which case you can’t do science. Unwilling to do that, some thinkers claim that causality is an empirical law that applies only to this world, not beyond it, but they contradict themselves by having no empirical evidence for that. And note that this argument from causality is totally unaffected by evolution, which is why the Church says you’re free to believe in the evolution of man’s body from the animal kingdom if you choose to do so.

The immateriality of the intellect

You are not free, however, to believe that man’s intellect evolved from matter. And materialists also understand this — hence their denial of rationality (including their own) and free will. These two things stand or fall together. If your mind is merely your brain, it’s material and, like all matter, obeys the laws of physics, not the laws of logic. You don’t make rational choices. All your thoughts and actions are either determined by blind physical causation or random.

But I didn’t fully understand the significance of the materialist denial of intellect and free will until I understood that these are man’s specifically spiritual powers — the image of God in us. Like most people, I’d focused on discussions about consciousness. But that’s not the philosophically important thing. And it’s not what separates man, the rational animal, from the non-rational animals.

Because we have intellects, we have the power of conceptual thought. As Mortimer Adler pointed out, only man uses ‘signs that are name-words to refer to imperceptible objects.’ Dolphins (or whatever “smart” animal you care to mention) don’t refer to concepts like justice, circularity, etc. Unlike any other animals, however, we can grasp these universals — something impossible for any purely material faculty.

Take the example of colour. Your senses tell you about particular colours: the apple is red, for example, and the banana is yellow. But you can go beyond this to understand the universal concept of colour. Although it’s always the same, it can be attributed to all colours — like the concept of circularity can be attributed to all circles. Non-rational animals can’t do this, and it means the intellect can’t be material. The abstraction “colour” isn’t located somewhere in your brain.

Moreover, when we combine concepts to form judgements and go from one judgement to the next in accordance with the laws of logic, we are rationally affirm or deny our conclusions — something that would be impossible if all our thoughts were the product of a purely physically determined process. And we can also understand that some truths are necessarily true beyond our material world. 1+1+2, for example, is true in all possible worlds — something that you absolutely do not need to know for pragmatic survival purposes on earth. And it’d be true even if no material worlds at all existed.

Moreover, our hunger for truth is itself evidence for the immateriality of the intellect. Your eyes, for example, are injured by light that’s too bright, and your ears are hurt by sound that’s too loud. And that’s the case with all material faculties. But the intellect, being immaterial, is perfected rather than injured by highly intelligible objects, and that’s because ultimately it thirsts for God — infinite Truth.

Because the intellect is immaterial, there are philosophical arguments to show that it’s necessarily simple (i.e., not composed of parts as all material things are). That means it cannot corrupt or decompose, making it immortal. And of course human beings, alone among all animals, desire to live forever. Why? Because the desire of a knowing being is proportionate to its knowledge. Since we can know existence abstracted from time — exactly what it means to live forever — we naturally desire it. But this natural desire isn’t in vain.

The Resurrection

Philosophical arguments can get you to theism and the immortality of the soul. Plato and Aristotle go that far. But Christianity was founded on the Resurrection. If the Resurrection didn’t happen, Christianity is false. But we need the philosophical groundwork that natural reason gives us. You don’t start by assuming miracles are improbable. You start by establishing the existence of God and the soul.

And then you consider the Resurrection — the greatest event in human history. There’s no running away from it. You have to make your mind up. Even an agnostic ultimately lives as if the Resurrection is either true or not. The tomb was empty: the Resurrection was preached in Jerusalem just a few weeks after the crucifixion, and if the tomb had not been empty, such preaching could not have occurred. Jesus’s enemies would have loved nothing more than to produce his body to stop it. But they couldn’t.

As the Cambridge New Testament scholar C. F. D. Moule said, “If the coming into existence of the Nazarenes, a phenomenon undeniably attested to by the New Testament, rips a great hole in history, a hole of the size and shape of Resurrection, what does the secular historian propose to stop it up with?”

Here’s the critical question: did the disciples steal the body then die for what they knew to be lie? Most people won’t even die for what they know to be the truth. They’ll rarely even lose a job or some minor comfort for it. Jesus’s disciples, however, had nothing to gain by lying and starting a new religion except hardship, ridicule, hostility, damning their souls to hell according to the religious beliefs of the time, and martyrdom. And they had plenty of opportunities to admit their deception, yet not one of them folded.

There’s also no reason why the disciples would have told a lie with women as witnesses. In first-century Judaism, a woman's testimony was virtually worthless. |Women were only rarely allowed to give testimony in court, so making up a story with women as the first witnesses to the empty tomb would have damaged its credibility. One of the witnesses, Mary Magdalene, had been possessed by demons (Luke 8:2), making her even less credible.

The idea that the disciples were hallucinating is also absurd. Christ appeared to a group of five hundred, and mass hallucinations don’t occur. Moreover, hallucinations depend very much on cultural beliefs, and in the Jewish tradition visions only appeared to individuals. There’s also the fact that numerous visions took place over forty days, and the Risen Christ was capable of eating (Luke 24:41-43).

And the disciples were not men prone to anxiety or flights of fancy — the sort prone to hallucinations. In fact, they themselves did not believe at first: “But these words seemed to them an idle tale, and they did not believe them" (Luke 24:11). Paul, for example, was a first-rate intellectual, who had decades to reflect on his vision of Jesus in the light of his hardships and facing death, yet he didn’t deny Him.

Thinking it out to a conclusion

Those were my three stepping stones to faith: the God as the Necessary Being, the immateriality of the intellect, and the Resurrection. And the alternative conclusions must be faced. Most people don’t want to do this. As T. S. Eliot said, ‘when the ordinary man calls himself a sceptic or an unbeliever, that is ordinarily a simple pose, cloaking a disinclination to think anything out to a conclusion.’

So think it out to a conclusion:

• Did the universe create itself?

• Do you have intellect and free will?

• Did the disciples lie?