For nearly two thousand years, Judeo-Christian thought has dominated Western civilization. One of the fundamental assumptions of this mindset is that there exists a God who is interested in humans here on the Earth. Historically and specifically, the Christian mindset is a description of the universe that attributes various facts and phenomena to the intervention in physical affairs of an incorporeal, supernatural, almighty Creator God. This way of looking at the universe, even now, has an incredibly strong hold on the minds of a vast majority of Americans; in particular, American fundamentalists have latched onto the literal truth of the Bible as a core belief, and have shaped their worldview based on its literal truth.
A new way of looking at the world has arisen in the past three hundred years, however: a scientific mindset. I've laid out the scientific method in the previous article of the sequence. Its importance cannot be overstated: since the advent of modern science, Western civilization has exploded and come to dominate the world. Science, by letting us understand and exploit nature, is single-handedly responsible for the luxury in which you and I live, luxury unheard-of for the vast majority of human history, whether you think it to be six thousand or six hundred thousand years.
At the heart of the conflict between evolution and creationism is an apparent clash between two worldviews: on the one hand, the Biblical literalism of fundamentalist Christianity; on the other, methodological naturalism. Can the scientific method be reconciled with Biblical literalism, and with Christianity in general? Yes, and no.
To start with, we need to have a working definition of "worldview". For the purpose of this article, I've taken the word to mean "a model of the universe". To clarify, each person holds a model of the universe in his own head: his idea of how natural phenomena work and fit together, as well as any spiritual phenomena he might believe in. For example, Christians for a thousand years believed the Sun revolved around the Earth. This was a relatively important part of the Christian worldview: the generally-held Christian model of the universe. God had put the Earth and humans at the center of the universe, with the planets, sun, moon, and stars fixed into crystal spheres that revolved around the Earth. Heaven existed physically outside of the farthest sphere.
Now consider a scientific worldview. Science is unique among worldviews because, instead of being incidental to some belief system, the goal of science is to create a description of the universe around us. So the scientific worldview is constantly changing and becoming more and more accurate as we humans apply the scientific method to the challenge of describing the world. Take as an example the progression of our scientific understanding of the Earth's place in the universe: from Ptolemaic geocentrism to Copernican heliocentrism to Keplerian heliocentrism to Newton's laws to our current understanding based on relativity theory. Over two millennia, the scientific worldview has refined itself to the point where we can say with precision measured in meters exactly where each object in the solar system larger than a few meters wide is.
In fact, heliocentrism is a good historical example of conflicting worldviews. The Christian worldview of the time was, as I've mentioned, Earth-centric. As the scientific worldview changed to more accurately describe the universe, it became heliocentric. Of course, the Church then worked actively to suppress heliocentrism, going so far as to ban and burn Copernicus' and Galileo's books. By the time of Newton, however, heliocentrism was not actively challenged: Newton gained considerable support for his scientific contributions by deriving Kepler's three laws of planetary motion, the mainstay of a heliocentric solar system, from his laws of motion and gravitation.
Why does heliocentrism remain unchallenged? After all, there certainly exist Christian worldviews that are not heliocentric: a strictly literal interpretation of scripture requires that the Earth be flat and rectangular (Rev. 20), floating on water (Gen. 1), and with the sun revolving about it (Joshua). I figure that heliocentrism is still accepted today because it makes sense, and has been a part of the education of six or seven generations of children. Anti-Copernicans might challenge that heliocentrism's accepted today because it's been brainwashed into the culture to defy the authority of holy scripture. Decide for yourself whether or not this objection holds.
Could a terracentric Christian worldview coexist with the data available today? Sure; but there would have to be many ad hoc revisions of the worldview based on evidence like the Hubble Deep Field. These revisions would have to make the argument "No, the solar system is Ptolemaic, but God created it so that it would look heliocentric." Moreover, nobody would seriously accept the claim that an Earth-centered worldview is scientific.
Today, almost everybody respects science. As I described in the introduction, science is responsible for the great wealth and luxury in which we live. Universally, scientific experts are looked up to with awe. Because of this respect, the response of creationists to evolution is not to attack the scientific merits of evolution, but rather to attack the idea that evolution is scientific in the first place. Instead, creationists often attempt to pass off creation "science" as scientific.
To do this, some creationists make a distinction between "historical" science and "operational" science, and attack the former as unscientific. Is this a false division of scientific disciplines? Go back to the scientific method page and look again for something -- anything! -- that indicates science treats historical events any differently than current events. Is the repetition of the event itself a requirement of science? No! We need only to be able to test the hypothesis, and we can do this by testing the modern consequences of a historical event. Like a crime scene, we are able to put together a description of past events by looking at what's left and testing our hypothesis against these remains. After all, if science were confined to a laboratory, the fact the Earth revolves around the Sun would be speculation coequal in validity with the proposal that the sun revolves around the Earth!
So there's no distinction at all between the science of past events and the science of current events. Now, how about the claim that creationism is scientific? Go back to the scientific method page again and read the part about falsification. At its broadest, creationism is simply the proposition that God created the universe. Is there any way to disprove the assertion that an Almighty God created everything? Of course not! A God who can create ex nihilo can certainly arrange matter any way he wants. Any form of creationism, be it my belief that God laid the laws of physics down or the belief of Answers in Genesis that the creation event was ten thousand years ago and took six days, is patently unscientific because there is no way to test it.
Can a creationist, literalist worldview coexist with the data today? Yes, but it must admit that it cannot be scientific.