Religion and Science

Religion and Science
by Professor Peter Kreeft

From a lecture series given in 2006, transcribed 2019

Note: click here to go to "creation versus evolution."

If you ask most intelligent atheists for the two strongest arguments against the existence of God, they would probably say the problem of evil and the conflicts between religion and science. That second one is our topic in this lecture. It's one of the two objections to the existence of God listed by Thomas Aquinas in his Summa Theologica. When he wrote that 4,000-page long book, he divided it into thousands of separate questions all in logical order, and the very first question after defining theology is whether there is a God. For if God doesn't exist, theology can't exist either because it has nothing to talk about. Well, Aquinas always tries to find three objections to every thesis he tries to prove because he wants to be scrupulously fair to his opponents, but he can only find two objections to God's existence. The first one is the problem of evil, and the second is essentially the one we'll be looking at in this lecture, the argument that belief in God is unscientific.

Aquinas' formulation of the objection is very short and simple as usual. It is unscientific to choose a more complex explanation when a simpler one will do. This is essentially Occam's Razor, which was one of our twenty arguments for atheism. Aquinas accepts this principle but argues that it does not necessitate atheism. But it seems to. Here is the argument. It is superfluous to use a complex explanation if a simpler one will do, but everything we experience can be accounted for on the hypothesis that there is no God. For everything that happens happens either with or without human will. What happens without human will happens by nature, and the natural sciences explain this. What happens by human will is explained by the human sciences, and there is no remainder in the data that can be explained only by God. Therefore, God is superfluous. In other words, God is like little green men or conspiracy theories: you may not be able to disprove these hypotheses but you can't prove them either and they are unscientific. They are neither verifiable nor falsifiable.

The notion that science has disproved religion is very influential in the history of Western thought. The decline of religion and the rise of science happened together historically and this is certainly no coincidence. But the claim that science has disproved religion is far too vague to argue about logically until we answer another question: which discovery of which science has refuted which claim of which religion? If we want to be scientific, we have to be specific. So, let's look at six specific issues, six specific religious beliefs that seem to be unscientific: the supernatural, miracles, angels and demons, divine providence, human free will, and creation.

First let's define naturalism and supernaturalism. Naturalism is the philosophy that says nature is all there is. Supernaturalism is the philosophy that says it isn't. Let's define nature as the whole interlocking system of causes and effects that we call the universe, all the material entities that exist, and all of space and time. Religion claims that this universe or nature is not all there is, there's something more. The "supernatural" means literally, the "more than natural." I think that's a better way to define the supernatural than calling it something outside the universe because that's a self-contradiction. That would be talking about a place outside space or a time before time. Now the question is, is belief in the supernatural unscientific? That's probably the most general question about the relation between religion and science. For all the more specific issues, like miracles, or creation and evolution, come under this heading. The cause of any miracle, or the cause of the act of creation, or the cause of divine providence is something supernatural, even if the effect is in each case, something in nature.

Well, in one sense the supernatural is obviously unscientific. Religious beliefs are not discoverable or provable by scientific means. But most believers do not claim that they are. If they did, the issue could be settled by purely scientific means. That's why we need philosophers and not just scientists to mediate the argument about science and religion. Neither science nor religion as the defendant and the plaintiff have the right to be the judge. Naturalism versus supernaturalism is an issue about "isms," a philosophical issue, an issue between two philosophies, not between two scientific hypotheses or between two religions. Science can no more refute supernaturalism by a laboratory experiment than religion can refute naturalism by a church service. If either "ism" is going to be proved or disproved it must be done by philosophical argument.

Atheists admit that many beliefs that they themselves hold to be true and reasonable are not scientific in the sense that science can't prove them — for instance that your wife loves you, or that human consciousness is not one large dream, or that tomorrow will come, or that sunsets are beautiful, or that we ought to be honest, or that Shakespeare is a great writer. The question is whether science can disprove the supernatural, either in general or in particular examples of it, such as miracles.

Well, it's hard to see how science could either prove or disprove the existence of a realm or dimension that claims to be beyond its competence and instruments to detect. That would be like expecting an unborn baby to discover or prove the existence of the world outside the womb, or to disprove it. How could he do either? If the atheist argues, as one famously did, I do not believe in God because I do not find him in my test tube, the believer can fairly reply that if he did find God in his test tube, he would be confusing God with a chemical.

But the atheist can put the argument in a much better form than that. The scientific method has proved to be the only certain and reliable method ever discovered for discovering and proving facts or objective truths. But this method does not detect any religious facts, any supernatural truths. This may be true, but does it logically follow that therefore we should not believe in anything that is beyond the scientific method? There's no way of proving by the scientific method alone that we should not believe anything beyond the scientific method. So the principle, "don't believe anything that can't be proved by the scientific method" is not provable. In fact, it's disprovable(!) without any assumptions at all because it's self-contradictory: that principle itself can't be proved by the scientific method. It can only be assumed, or believed, or practiced, but not proved. In fact, it's exactly like religion that way.

But if science can't disprove the supernatural, science can't prove it either. Attempts by religious believers to convince the world by supposedly scientifically detectable miracles have all failed for two reasons: First, miracles are unique and not repeatable in laboratory experiments; second, even if they happened, they are like meteors. Even if they do come from beyond the earth, once they enter this world they become parts of nature. For instance, if a virgin birth happens, it follows the same nine-month cycle of pregnancy as every other one. Or, even if Jesus is both divine and human as Christians believe, he is as totally human as any other human. his divinity, if it exists, does not appear directly as a visible part of nature because that would not be supernatural, but part of nature.

Pretty obviously, the supernatural, and God, and miracles all go together as a package deal. There might be a God without miracles, God might be able but not willing to do them, but there can't be miracles without a God, and miracles would be the most spectacular example of the supernatural. Also, miracles are crucial for Christianity. If miracles don't happen then the world's largest religion is false, for all of its main claims, its central doctrines, are miracles: creation, divine revelation and prophecy, Jesus' Incarnation and Resurrection, last judgment. If Jesus' bones were discovered today in some tomb in Israel, there would be no Christianity tomorrow. And, at least some of these miracles are also essential to religious Judaism and Islam — creation, divine revelation, prophets, last judgment. If it wasn't God but Moses who invented the Ten Commandments, or if it wasn't Allah but Mohammed who invented the Koran, well then the authority of Judaism and Islam would be undermined.

But miracles are not essential to eastern religions. For one thing, there is usually no transcendent God — no Creator — to work them, and for another thing there is no clear distinction between nature and super-nature, or even between the human soul at its depths and God.

One argument against miracles is that they're illogical. But I think that's a misunderstanding. What's illogical is contradictions. Miracles, whether they happen or not, are not contradictions. A corpse rising from the dead after four days is a miracle. A corpse both rising and not rising at the same time is a contradiction. But a second argument is historical — that belief in miracles stems from ignorance of the laws of nature. People believed in Zeus before the science of meteorology, and they believed in virgin births before gynecology. This argument has three weaknesses, I think. First, the fact that belief in Zeus did arise during ignorance of meteorology doesn't prove that it arose because of that ignorance. Second, a knowledge of principles like gynecology doesn't make a virgin birth any more or less believable or any more or less miraculous, it just supplies the details of how a baby develops once it's there, whether its cause is man or God. People who were ignorant of gynecology knew that women didn't get pregnant without men. Finally, belief in miracles can't stem from ignorance of the laws of nature because the very concept of a miracle presupposes a knowledge of the laws of nature. The very concept of an event whose cause is supernatural is a meaningless concept unless there is a natural order. Unless there are laws, there can be no exceptions to them.

A third argument against miracles, a stronger one, is that they would violate the laws of nature, and thus they would demean the laws of nature. But by analogy that's questionable. A presidential pardon would not violate or demean the laws of a court, or a school principal cancelling classes would not violate the laws of the school, because both act within their proper authority, and if there is a Creator presumably he would have authority over all his creation.

A fourth argument against miracles is that they would demean God. If God has to intervene and interfere in his creation, He looks like a bad architect patching up an imperfect house. But that presupposes that God designed a system in which He should never intervene with miracles, a world he originally wanted to be empty of prophecies or answered prayers or divine revelations. But the theist's claim is that those miracles were part of his original plan. Both sides are consistent so far.

A fifth argument, a famous one from David Hume, is that miracles are maximally improbable. It is always more probable that someone is lying or hallucinating because those things happen often, while miracles by definition are unrepeatable singularities. Of course, each person is also an unrepeatable singularity and so are many non-miraculous events in your life. Miracles are events whose cause is supposedly outside the universe, so how can any observation of events inside the universe, and how probable they are, determine how probable it is that God might add another event? Wouldn't that be like fish in a fishbowl trying to calculate the probability of a wholly new fish being added to the bowl? They would have no data in the fishbowl that could give them any reason for that. Should a new fish be added or not? Is it probable or not? You'd have to know the person who set up the fishbowl to know how likely it would be that he would choose to add a new fish.

Here are two arguments for the possibility of miracles, one from the side of the cause, the God who could work miracles, and one from the side of the effect, the universe that would receive them. And the argument is that there is no sure defense against miracles in either place. For if God exists, there is nothing in the nature of God that assures us that he would never work miracles — or that he would — and there is nothing in the nature of the universe that would exclude miracles. Nature is defenseless against them. And if God created the universe he could certainly perform miracles in it. If he banged out the Big Bang, why couldn't he bang out little bangs? If the author made the play, couldn't he change it, couldn't he even enter it himself as one of his characters?

Those arguments seem to show that if God exists, miracles are possible. But are they actual? Do they happen? That's a quite different question, and I don't see how philosophers can decide that. That's a question for experience and history. The things proved by both science and philosophy are universal statements like equations. They're not singular, unrepeatable events, whether natural or supernatural. It's history that investigates singular events and history cannot prove its conclusions with the certainty of a formula.

So how do you investigate a claim that a miracle happened? In the same way you investigate the claim that a non-miraculous event happened — historically and empirically. The historian should investigate whether Jesus rose from the dead — or not — in the same way he investigates whether Caesar crossed the Rubicon or not or whether the President really had the flu last week. He looks at his data: the claims, the witnesses, the documents, the effects of the event. He doesn't know a priori before he looks at the data, and he shouldn't claim to. That would be prejudice — judging before the evidence is in.

Another supposedly unscientific religious belief is angels and demons. You may be surprised to hear a philosopher arguing about angels and demons, but the issue is certainly interesting and investigatable. Interesting, because they are extra-terrestrial life forms, and investigatable because there are far more accounts of them than any other kind of extra-terrestrial life form. So, are they facts or fictions?

For some reason, many people think belief in angels is more unscientific than belief in God. But if there is a God — an infinite and uncreated Spirit — there is no reason there couldn't also be angels, that is, finite created spirits without bodies which have intellect and will, and if these creatures had free will they could choose evil and become evil spirits or demons, or they could choose to be good angels. So the hypothesis is not logically inconsistent. But I don't see how it's logically provable, either. I don't see how any of the arguments for God's existence proves angels' existence.

Theists sometimes argue that the existence of angels is probable or likely for two reasons: the first is an argument from authority, and the second is an argument from analogy.

The first argument for angels is that most religions teach it. So if religions are reliable on other things there's no reason to make an exception about that part of their teaching. And the majority of all peoples and cultures and traditions and myths and religions in history have believed in some kind of angels or super-human spirits.

The second argument is from the analogy with the rest of the universe. There are many animal species between plants and humans, and many kind of plants between animals and minerals. The great chain of being is not full of gaps, not missing any basic links, but the distance between man and God is a great gap. Super-human creatures are just as possible as sub-human life forms. And if this subhuman fullness and variety is from the Creator, he would seem to have a penchant for fullness and variety. The universe seems to be his lesson in diversity education, and in wide imagination, and in not closing our minds. As Hamlet reminds Horatio when he sees a ghost, "there are more things in heaven and earth, Horatio, than are dreamed of in your philosophies." This argument doesn't even claim to make the existence of angels proved, but only reasonable.

Another religious belief that's often challenged as unscientific is divine providence. Religious believers see their lives as parts of something like a play, with a story line that's known and planned by God, or fate, or destiny. And even if God is only impersonal karmic law, rather than a personal, providing father, still the religious world view claims that life contains destiny as well as free choice, like a great story. This is the big difference that belief in something like divine providence makes; this is the bottom line or payoff. If life is a story, it's not full of sound and fury signifying nothing, but signifying something. And then we can ask the question Sam asks Frodo as they wander through Mordor, "I wonder what kind of a story we're in?" — a nice way of asking what is the meaning of life. But that presupposes that we are in a story.

The difference between not believing in divine providence and believing is enormous so it's an issue worth thinking about. As with the issue of miracles, there may be enough data either way to make the belief more or less probable, more or less reasonable, but there doesn't seem to be any conclusive proof either way, and it's hard to evaluate this data, or even to identify it. As with the problem of evil, there seems to be no cutoff point, no specifiable amount of order or disorder that would prove or disprove divine providence. How do you know that a given event is providential or random? You intuit it, more than you prove it. Perhaps stories are more convincing than arguments, stories like Sartre's Nausea on the one hand, or Becket's Waiting for Godot that show a non-providential world; or stories like, The Lord of the Rings, or The Bridge of San Louis Rey, that claim to show a providential world. Which kind of story is more like life? That's a very difficult argument logically. You just see it.

The concept of predestination is easier to argue about. It's similar to providence but it's much stronger. Yet those who say that science contradicts religion concerning divine providence often argue not against this stronger providence or predestination, but for it! For a kind of predestination, and against human free will, but not a divine predestination. That is, many atheists argue that all human acts are determined or predetermined by a series of unfree causes, a kind of lower predestination, or a predestination without God. Therefore there is no such thing as a soul with free will. Whether you're thinking of a predestinating God from above or a chain of physical causes from below that reaches back to the origin of the universe, if they are all that is causing my acts, then those acts are not free. So those who embrace either kind of predestination, from above or from below, from a Calvinistic God or from a deterministic nature, have arguments against free will, and would argue that this notion is unscientific. They often argue this way: The acts that I call free choices either have causes or not. If they have causes, they're not free. If they don't have causes, they can't exist, for everything that exists as an event in time needs a cause.

To explore that argument we should briefly look at both kinds of predestination, from above and from below, to see whether or not they contradict free will. For free will is crucial to all three Western religions. The idea of moral responsibility and the idea of commandments both seem to presuppose free will.

The theist tries to reconcile the idea of predestination with free will in three ways.

First, by pointing out that to know a thing is not to cause it, so the fact that God foreknows everything we will do doesn't mean that he does it, or causes it. We do it.

Second, the principle that God does not bypass, or rival or demean or remove natural causes but rather uses them and perfects them, and fulfills them, as a good king exalts his ministers, or as a good CEO doesn't micromanage but does things through middle management, or as light brings out all colors rather than blotting them out, or as good parents don't rival their children but try to mature them, or as good teachers try to teach their students to think for themselves and become their own teachers. If that principle is how God works, then even if God has not only foreknowledge but even causality towards human actions, that causality wouldn't destroy the nature of human actions anymore than it destroys the nature of anything else in nature. But the nature of human acts is to be free. Therefore, divine causality towards human actions would not take away their freedom; if it did it would take away their nature. How God does this I think is inconceivable.

Third, the theist could try to nuance or deliteralize the notion of predestination. God is not in time, so he cannot foreknow or predestine the future literally — that would put him in time [Ed. note: for a fuller exposition on God's relationship to time, see the book God and Time by Gregory Ganssle et al.]. To God, everything must be present, not past or future. God would be the "eternal contemporary" of everything that happens. If some fortune teller with a crystal ball infallibly foresees that you will climb a mountain tomorrow, then you can't not climb that mountain, so you're not free. But, if someone infallibly sees you climbing it, as you're climbing it, your act can still be free.

The defense of free will against the lower determinism I think is simpler than the defense against the higher determinism of predestination. If we're only very complex machines and not free, then all our moral language would seem to be meaningless. It is meaningless to praise or blame or command or forbid or encourage or discourage or give advice and counsel to a machine. When the Coke machine fails to deliver a Coke, we don't preach to it, or try to make it feel guilty and repent, we kick it. If there is no such thing as free will, there is no moral responsibility, and if there's no moral responsibility, there's no civilization. If the determinist begins to practice what he preaches, he will stop using moral language, since that language presupposes free will and responsibility. He'll stop preaching and start kicking. And if that happens, at that point the philosopher might have to call in something stronger than arguments: he might have to call in the cops.

Creation versus Evolution

The single example most people think of when they think of a conflict between science and religion today is creation versus evolution. What is the logical relationship between these two ideas? To make this complex question simpler, let's ask three questions: First, is creation possible? Second, is evolution possible? And Third, do creation and evolution contradict each other?

Well, first of all, if God exists, creation would be possible; if not, not. Omnipotence could do anything that's possible, and only logical contradictions are not possible. But isn't the notion of creation out of nothing logically contradictory? Out of nothing, comes nothing, ex nihil nihil fit. So isn't creation "the pop theory?" Well, no it isn't. The idea of creation does not claim that anything ever pops into existence without a cause. God has no cause, but he does not pop into existence, and the world pops into existence but it has a cause: God. In the theistic hypothesis the universe did not come from nothing, it came from God's creative act. But to say that God created it means that he didn't rely on previously existing material, as a potter uses clay to make a pot. Of course, if there's no Creator, creation is logically impossible, but if God exists it's not logically impossible that he would create a universe out of nothing.

Is evolution possible? Well, if it were impossible, that impossibility would have to come either from God or nature. There seems to be no reason in the nature of matter or life or time to think that evolution is impossible. There are scientific problems with the theory today, especially the absence of missing links or transitional forms, and the suddenness of the appearance of new species, but it's the only theory that accounts for most of the data. Religious fundamentalists usually dispute that and they argue that special creation of each distinct species also accounts for the data. Well, yes, but no one, including religious believers, ever uses that hypothesis, many repeated acts of miraculous special creation, to account for anything else.

There doesn't seem to be anything in the nature of the concept of God that would make evolution impossible. God could have created each star separately instead of having them emerge from clouds of stellar dust and each planet instead of having it emerge from a star and cool but that kind of micromanaging isn't his style. For that matter, he could have also created my memories of yesterday without there being a real yesterday. But that's not his style either. That would seem to be deceptive. So, fundamentalists who think the earth is only 6,000 years old and that the six days of creation were six literal 24-hour days are really saying that God created fossils of dinosaurs that never really existed, which would seem to be as deceptive and misleading as creating fossil memories in our minds of yesterdays that never really existed. What kind of arbitrary, tricky God would that be? But there are fundamentalists among the evolutionists too, who will no more allow any interpretation of evolution that would be open to intelligent design, than the religious fundamentalists will allow any symbolic interpretations of the days of creation that would allow long periods of time for evolution. Both kinds of fundamentalists seem to be kind of narrow-minded.

I see no logical contradiction between the ideas of creation and evolution. Millions of tons of ink have been spilled on this topic by fundamentalists on both sides who see the other side as its mortal enemy, so I will probably offend both sides by saying this, but it seems to me as a philosopher of religion that this war is a stupid one! For whether or not the creation out of nothing of the universe by God actually happened, as Genesis says, and whether or not the evolution of species by natural selection actually happened, as Darwin says, the two ideas neither exclude nor include each other. Either could be true, without the other one being true, or both could be true, or both could be false. They are like the idea that I wrote this book, and that the text of this book came off a laptop computer and onto a disk. The first claim is about who, and the second about how.

Let's distinguish five different questions about origins: the origin of matter, of organic life, of different species of plants and animals, of the human body, and of the human soul.

Evolution does not claim to answer the first question, the origin of matter. Evolution is a biological theory about how living species arrived on this planet, not an astronomical theory about the beginning of all matter, time and space. Evolution does not claim to explain the rest of the universe outside this earth, or where the universe came from, or where matter came from. It's not a cosmological theory, but a biological theory. The cosmological theory of the Big Bang is very closely compatible with the religious belief in the instantaneous creation of the heavens and the earth out of nothing by God, even though science sees nothing of God or of the very act of creation, or even whether this act was a creation out of nothing; still, it does see in the universe the sort of thing that religion predicts it would see.

The second of these questions about whether life could have come from inorganic matter is also not a question about evolution in the proper sense, but about the relation between inorganic and organic chemistry, and both scientists and theologians are divided among themselves about that. That's not a contradiction between science and religion.

Evolution concerns the third and fourth questions about the origins of plant and animal species and the origin of man insofar as he is an animal species.

But the theory of evolution does not claim to answer the fifth question, the origin of the human soul, because the soul is not a scientific entity and is not in principle scientifically verifiable or falsifiable. If souls did exist, they would leave no fossils. By the hypothesis they are not visible. So if a scientist claims that evolution explains the soul, he's being a bad philosopher. That's like saying chemistry proves atheism by not finding God in a test tube. It's a misunderstanding of the meaning of the hypothesis. Human souls, if they exist, are spirits, not molecules — spirits that give life to human bodies and leave those bodies at death. They're not pure spirits like angels which have no bodies, but they are spirits — that's the hypothesis. Well, spirits aren't made of atoms. Even if they are the spirits of bodies that are made of atoms. You can't weigh the soul that leaves your body after death; you can only weigh bodies. That's been tried by the way, a number of times. People were put on beds, beds were put on scales, scales were carefully calibrated. At the moment of death, they tried to weigh the soul. They didn't find any difference. Spirits can't be explained by matter. You can't get spirits out of matter no matter how much matter you have, no matter how complexly you put it together, any more than you can squeeze blood out of a stone. You don't get consciousness of atoms just by lining up enough atoms in the right arrangement, because the knowledge of any thing is a different kind of thing from that thing. Awareness of the material universe cannot be one of the material parts of that universe. Knowledge of a thing always transcends the thing known. Bodies are known, not things that know.

Now, all three theistic religions teach that God created human souls directly. That may be true or false but it doesn't contradict the idea that bodies evolved gradually. In fact, the book of Genesis could even be interpreted to suggest a fit between the two, for it says that God formed man, that is, man's body, out of the dust of the ground. It doesn't use the word for create there. Then he breathed into man the breath of life. The Hebrew word ruach means both breath and spirit. If an evolutionist claims that there is no divine design, that's a philosophical or religious statement, but not a scientific one. If the atheist replies that evolutionary science is evidence for atheism and the absence of divine design because natural selection can explain the emergence of new species without God, well it can, but that's like saying science is evidence for atheism because obstetrics can explain babies without God or meteorology can explain thunder without God, but the religious believer claims that God is the first cause, the Creator, but not the perpetual miracle-worker. The hypothesis is not really disproved by the data. And the scientist explores only the visible data, the natural causes, not the invisible divine first cause, so I don't see how in principle those two claims could contradict each other, because they don't really "meet."

The issue is a tempest in a teapot. It's high time for both sides to get over it. It's a scientific issue, not a religious issue, until both sides make it a religious issue. It may also involve reading a book wrongly, interpreting Genesis as if it means to be a rival to the Origin of Species, and interpreting the Origin of Species as if it means to be a new book of Genesis.


Professor Kreeft