There are many on the left and in the "scientific community," so to speak, who are afraid of that discussion because oh my goodness you might mention the word, God-forbid, “God” in the classroom, or “Creator,” or that there may be some things that are inexplainable by nature where there may be, where it’s better explained by a Creator, of course we can’t have that discussion. It’s very interesting that you have a situation that science will only allow things in the classroom that are consistent with a non-Creator idea of how we got here, as if somehow or another that’s scientific. Well maybe the science points to the fact that maybe science doesn’t explain all these things. And if it does point to that, why don’t you pursue that? But you can’t because it’s not science, but if science is pointing you there how can you say it’s not science? It’s worth the debate.There is, of course, nothing surprising about Santorum's argument, he's made it many times before. Science curricula are probably not terribly threatened by his candidacy -- he's polling in single digits at present -- but still, his views reflect those of a large section of our country, and the question is often posed. Why, exactly, can't God be a part of the equation when it comes to science classes?
Separation of church and state is where the conversation usually begins. And for good reason: it's a guiding principle we would probably be well advised to follow. As the founding fathers realized, governments will work better if they are decoupled from religion, because religion introduces a whole series of complications which are best avoided. We need only look at the regime in Iran to see the perils of mixing religion and government. In spite of the fact that Christian theology is largely built around peace and harmony ("Blessed are the meek, for they shall inherit the Earth," says Jesus on the mount), and other religions similarly advocate such values, terrible wars have been fought in the name of religion, and religious zealotry remains a serious threat in the world. That is not to say that religion is inherently violent... such a statement would be itself too zealous. But it is worth noting... no war has ever been fought over science, by contrast. That's because science is not an ideology, any more than math is an ideology. It has its rules and regulations, but it is a tool more than it is a system of beliefs.
What's so terribly ironic about the separation of church and state debate is that many of the people who advocate so strongly for introducing God to the science classroom are some of the same people who are so terrified of that imaginary threat of Sharia Law, which is supposedly spreading across the nation like a virus. Perhaps ironic is not the right word. Those who attack the Sharia Law straw man fail to see the connection between their desire to bring their God into the law of the land, and the (imagined) desire of their Muslim counterparts to do the same. Of course, they would counter by saying that Islam is a violent religion, one that seeks to sanction honor killings in the United States. There are obviously significant cultural differences throughout the world when it comes to what constitutes moral behavior, but there can be no doubt in this case: there is certainly no place for such brutality in a civilized society. Even so, when it comes to violence, Christianity doesn't exactly have a spotless record, either, and there's a slippery slope when it comes to theocracies. What starts as a benign attempt to create a faith-based utopia can easily become a government that demonizes, harasses, imprisons, tortures or even executes dissenters. Such things have happened many times in the history of humanity, and indeed, such things continue today in some parts of the world.
But the church and state debate is a political argument, not a scientific one. Why God really can't be in the science classroom is because the God hypothesis is wholly antithetical to the way science is performed*. Science relies on the notion that experiments can be designed, claims can be substantiated, hypotheses can be tested; and regardless of your opinions about religion, it's clear that these rules simply cannot be applied. There is no way to test the God hypothesis. There is no experiment that can be tried that will either prove or refute the existence of God, and no formula that can describe the probability of God's existence (creationists sometimes try to go the other way, calculating, for instance, the probability of a DNA molecule spontaneously falling together on its own, thereby supposing to calculate the improbability of life's genesis without divine intervention. Unfortunately for these clever apologists, these calculations are founded on a number of flawed assumptions I won't go into here).
In short, God has to be left out of the equation because God is not a variable that can be considered in any meaningful way. God, as he is usually imagined, has no mass, no length, no density or energy or anything else you might wish to measure. There's no way to quantify the God variable. But why can't we simply say that God is a sort of catch-all variable, that factors in whenever we can't get the numbers to work? Well, if we did that, we just wouldn't get anything done.
There was a time, not very long ago, when we imagined that the gods were in charge of the motions of the planets. Not in a way that we might think of it today, of course; today you might hear someone say that God created the universe and set the planets on their orbits around the Sun. But to the ancients, the planets were moving across the sky under the direct control of the gods. In some cultures, the Sun was considered a real deity, crossing the sky in a boat or a chariot. The universe was then a mystery to us, and there seemed to be no way that these objects could move amongst the stars unless there was some sort of divine hand steering them. It's not that our ancestors were stupid to come up with these explanations, it's just that humanity was groping around in the darkness for millennia, struggling desperately to make sense of a world that operates with hidden mechanisms. Indeed, modern humans have walked the Earth for many thousands of years, but it's only in the last 500 years or so that scientists like Copernicus, Newton, Galileo, and Kepler (among many others) have been able to grasp the true nature of our solar system, and by extension, the wider universe.
But suppose we had been content with our original explanation, that the gods were directly involved with the motions of the celestial sphere. Suppose we were content to say that the laws of physics simply could not be deduced, that it was beyond us, that it was simply the realm of the gods. Without a systematic way of describing the natural world, it might've been argued that the god hypothesis offers a better explanation to the question of why objects fall. Before we know the answer to that question, it's much easier to simply say, "that's the way the gods want it to work," or, "the gods made it fall." Then, as now, the intentions of the gods would have been opaque to us, and we might have been satisfied to keep it that way. After all, the planets never seem to come down out of the sky to intervene in our affairs, so what does it really matter anyway?
Well, had we not pushed ourselves beyond these mystical interpretations of natural phenomena, we would be, essentially, stuck in the Bronze Age. We would be unable to understand the mechanism behind the changing of seasons, for instance. The ancients experienced the oscillation of the warm and cold months, and figured out they could predict the seasons by observing the sky, but you need a model of the solar system to understand why it happens. Had we not given up the planet-god hypothesis, we might still run away in terror during an eclipse of the Sun or Moon. We would have no weather satellites, no communications satellites, no space telescopes, no spacecraft examining the planets up close. The window into our origins, opened for us by modern astronomy, would be forever closed to us. Without physics -- a system of describing the mechanics once thought to be the realm of the gods -- we would be incapable of these marvelous things. But the laws of physics were not handed down from on high; they were deduced with painstaking work and an unyielding devotion to the facts. Our modern world enjoys the fruits of that bold rejection of mysticism.
It can be hard, sometimes, to imagine the world that existed in the time of Galileo, when something like a heliocentric model of the solar system could be seen as a major threat to Church doctrine. The structure of the solar system seems to us today a trivial matter, hardly threatening to prove God doesn't exist. But do we not still have those who doubt, beyond all reasonableness, the discoveries of modern physics? Consider the mental gymnastics performed by creationists who simply cannot accept the central revelation of modern cosmology, namely, that our universe is billions of years old. Elaborate alternative explanations have been imagined to explain why we can see the light from galaxies billions of light years away, even though we live in a universe that is, they say, only six to ten thousand years old. Their rigid theology of Biblical literalism requires them to discount the major discoveries of physics, astronomy, cosmology, chemistry, geology, biology, genetics, and paleontology. They would rather deny the great achievements of humanity's quest for knowledge than accept that their prized book may not have all the answers.
It's true that science doesn't have all the answers, either. But with the cosmos as vast as it is, there can be no such thing as an unabridged encyclopedia of the universe. We are incapable of knowing everything, but we've certainly learned a lot, and we're learning more all the time. Science has been the key to our success, and our survival, and we do a grave disservice to our children, and those who will follow them, when we trample on the central guidelines of this precious tool. Some of our discoveries may make us uncomfortable -- as Galileo's work made the Vatican uncomfortable -- but we gain nothing by burying our heads in the sand. Better to face the world as it is than to persist in delusion.
Those who dream of injecting theology into the science classroom believe that science is just another kind of religion, eager to stifle debate and indoctrinate susceptible minds with scientific dogma. But on the contrary, science depends on debate, it thrives on it. Some of the greatest discoveries have overturned what were once considered fundamental laws of nature. But not all debates are created equal: you can debate whether the tau neutrino can really travel faster than light, for example, but you can't really debate whether the Earth goes around the Sun. We've sort of figured that second one out, and if we had to constantly re-litigate every discovery we've ever made, there would be no time for new discoveries. Individuals are welcome to challenge any theory they like, but it takes a compelling argument to be taken seriously by the community.
The evidence for an old universe, or for evolution by natural selection, is far more abundant than can possibly be described here. But the problem is, the opponents of science do not believe in its methods, so there is a fundamental disconnect. Theirs is a faith-based worldview, and it cannot be tested; therefore they imagine that science is the same thing. They imagine that scientists are just clerics of a different sort. The situation is almost certainly made worse by the epistemic closure that is especially prevalent among those who feel there is some kind of mainstream conspiracy to silence them. When we can watch our polarized news, and attend schools that teach us what we want to hear, the gap between science and religion becomes wider and more difficult to bridge. It is a troubling state of affairs.
Those who support teaching the decidedly unscientific alternative to evolution known as intelligent design often say they want to "teach the controversy." It's become something of a joke for those on the other side, an easy punchline. But it's about as good a line as any that could be market tested. It begs the question, why can't we teach the controversy? And why are scientists so frustrated if they know they're right?
Richard Dawkins, the perennial wit, has imagined a perfect analogy. It's as though you have a crowd of people who sit in a Latin class and claim the Romans never existed. Of course none of us were around to see any Romans walking around speaking Latin, but we have great ruins of their once magnificent empire, we have paintings, statues, texts, and of course, the Romance languages which survive as the descendants of Latin. It's easy to see the parallels between this and the case for evolution. The evidence is abundant, so even if none of us have ever seen these ancient people alive, the evidence that they were once alive is overwhelming. No matter, the opponents of Latin education are unmoved, and by the way, they want you to teach the controversy, so that the kids will have all the facts: some people say the Romans existed, others say they didn't. No problem!
It's clear that science and religion just cannot exist in the same classroom, any more than math and philosophy can be combined in the same classroom ("Pythagoras tells us that A squared plus B squared equals C squared... but does the triangle really exist at all? How do we know?"). Science and religion need not be diametrically opposed to each other, but they are fundamentally different things. It will take more education, not just of scientific concepts, but of the nature of science as an endeavor, if we're to break through this dreary conflict.
*Note, the God hypothesis is antithetical to the way science is performed. That's not to say that religion and science must be mutually exclusive. Many theologians would argue that science and religion are perfectly compatible, and that the breathtaking discoveries of science reveal the true magnificence of God. The point here is that God is typically conceived as a supernatural being outside the boundaries of physical laws, so he/she/it is by definition beyond the scope of scientific proof or disproof.