Defining Science Transcript
"Only a Theory"
Creationists often reject evolution by saying that evolution is, quote, "only a theory." And that betrays either a deliberate or an unintentional misunderstanding of what a scientific theory is. Gravity is a theory—gravitational theory. Cell theory—all living things are constructed of cells. Electromagnetic theory, right? Germ theory? Germs make people sick. I mean, when you call evolution a theory, when you use the term "evolutionary theory," that's a very, very strong thing to say.
A theory in science is an explanation. It's a large system which has withstood some very, very rigorous testing, literally attempts to debunk it, and has survived all of those attempts. So when creationists try to dismiss evolution as "only a theory," they are misusing the word theory. They are using it in the ordinary sense, the non-scientific sense, of a hunch or a guess, and that's not what it means at all.
If you have a scientific theory, you have already done years, decades, of scientific work, hard scientific research that you have offered to the scientific community for their evaluation. But never a single time has any intelligent-design creationist ever done that. Yet they've created a public relations concoction that they present to the public and to the media that they have some cutting-edge science that really needs to be taught to children—that there is another side to this issue and it's only fair to tell it to the kids.
Well, there aren't two scientific sides to this issue, because there aren't two scientific theories. There's only one. And if you believe that children should be told the truth, you have to tell them that the only scientific theory which explains the shape of life on Earth is evolutionary theory. And if you tell them anything other than that, you're not telling them the truth, and that's hardly fair.
Avoiding the Supernatural
One of the core features of science for hundreds of years has been the reliance on natural explanations. And while it's true that there's various gray areas in defining the edges of science, in distinguishing science from pseudoscience, the issue of the supernatural is not one of those gray areas.
If you really look at the history of science, many scientific fields really didn't get started until supernatural explanations were discarded and natural explanations were adopted. Before evolution, this happened in geology, it happened in physics. A famous example is Benjamin Franklin, who in the 1700s proposed that lightning and electricity were the same thing, and proposed that lightning rods could stop lightning bolts from hitting church steeples and burning down churches. Some people accused Franklin of thwarting the will of God by doing this, but most people said Franklin had proposed a useful, natural explanation for a natural phenomenon and come up with a solution to a natural problem.
This is really fundamental to the history of science, the reliance on natural explanations. And it's not a trivial thing to just toss that out, particularly when the proponents of supernaturalism in science have nothing to propose except a miracle, except God did it or an intelligent designer did it, end of story, stop the investigation.
Scientists are never gonna buy that. And when a judge hears that, naturally a conservative judge isn't going to just redefine science and conduct a major scientific revolution on the say-so of a few intelligent-design experts. So the whole idea of redefining science really came back to bite the intelligent-design guys in the trial, and it really backfired.
Science and Religion
There are a lot of ways to define science. But I think the best definition is one that I've actually seen several states adopt for their K-12 educational programs, and that is that science is the human activity of seeking natural explanations for what we see in the natural world. What science isn't very good at is answering questions that also matter to us in a big way, such as the meaning and purpose of things. And what that means for the ordinary person is that there are a whole host of philosophical and moral questions that are important to us as human beings, but about which science cannot do anything more than inform us, and for which we have to make up our minds using a method outside of science.
Now, religion can also be defined in a whole variety of ways. What religion, I think, is, in a certain sense, is the attempt to account for the world which we see in terms that transcend the natural. In other words, in terms that include the natural world, but enclose it in a kind of spiritual worldview. This makes religion, I think, fundamentally a different kind of intellectual exercise from science.
There is absolutely no problem to a person of faith—and I'll include myself in this—for positing God as a cause of certain things. For all I know, my own ability to overcome a crisis in my life when I was 24 years old was due to the support that I prayed for from God. God could be responsible, no question about it, for the first living cell, or for certain animals that appeared in the Cambrian Explosion, or for the '69 Mets, which I've never been able to explain any other way. And I say that not to trivialize the idea, but to point out that supernatural causes for natural phenomena are always possible.
What's different, however, in the scientific view of this, is the acknowledgment, by scientists such as myself, even scientists who are people of faith, that if supernatural causes are there and are active, they are above our capacity to analyze and interpret. Saying that something has a supernatural cause is always possible. But saying that the supernatural can be investigated by science, which always has to work by natural tools and mechanisms, that's simply incorrect. So, by placing the supernatural as a cause in science, you effectively have what you might call a science-stopper. If you attribute an event to the supernatural, you can by definition investigate it no further.
On Isaac Newton
I think it's a gross mischaracterization to take scientists in the past who were people of faith—and Isaac Newton is a good example—and say that Newton worked on the basis of a hypothesis of design. Well, it's true that he certainly believed in a creator, and he believed that that creator was the architect of the universe he investigated. But here's the key difference. Newton never proposed God as a cause in any of his theories. In other words, he didn't seek to explain the way in which the prism broke light into many different colors by saying, "Well, it happens that way because it is God's will, and I will stop investigating." He sought a physical explanation, and his explanation was that light, white light, is composed of many colors, and what the prism does is to bend each color by a different amount. That's not a divine explanation. That doesn't use intelligent design. That's an explanation based on the principles of physics.
The point here is that what Newton and other scientists did was to assume that the universe made sense because it had a designer, and then to use what we would call ordinary material scientific methods to investigate that universe. That's just what science does today. What intelligent design pretends to do is to be in the tradition of Newton. What intelligent design actually is, to be perfectly honest, is they're in the tradition of the Middle Ages, where they stop investigation by saying, "We cannot answer this mystery; it is the work of God, the designer." This is a science-stopper.
A Solid Theory
I don't know where people get the idea that evolution is a theory in crisis. It is a theory in the sense that we use the word in science; that is, it is the strongest construct that we use.
The difference between what a theory means to the average person and what it means to a scientist is really completely opposite, because theories are very strong concepts in science. A theory is something that has been tested and tested over and over again, built on, revised. It continues to be reworked and revised.
The theory of evolution today is not like it was a hundred years ago. We have molecular genetics. We have developmental evolutionary biology. We have far more fossils than we had before. We have better kinds of phylogenetic techniques. Everything is improving through science. All of these things are becoming much better and better known.
And, so there's no crisis in evolution. It's healthier than ever. Do we have controversies? Sure, we do. Sure, we do. But, they're not about whether evolution occurred, or whether you can possibly see a unity to the ancestry of life. Those issues were settled. They were settled a century and a half ago.
Robert T. Pennock
Science is characterized, if nothing else, by its methods. It's not just the discoveries that we've made. It's characterized by the way of thinking—a way of providing answers in terms of empirical evidence. And it limits itself in its explanations to those sorts of things.
There's a big fancy term for this, it's methodological naturalism … scientific naturalism. And it says we can't appeal to the transcendent; we can't appeal to the divine. Probably the simplest way to explain this is in terms of a nice cartoon that Sidney Harris did in American Scientist a long time ago. It's got a scientist standing in front of a blackboard, and he's obviously been working at his series of equations and it covers the blackboard, but there's a gap in the middle. It's been too hard; he can't figure it out. And he's written in there, "Then a miracle occurs." And his colleague is looking at this and says, "I think you need to be a little more explicit there in step two."
And that, in sort of a cartoon version, is what methodological naturalism is. It says you can't have gaps that you fill in by appeal to miracles. That essentially stops scientific inquiry. Because if we could always appeal to the transcendent whenever we had an explanatory problem, it would make science too easy. You can't test that. You could always give as an explanation "God did it." Science says no, you've got to fill in the steps with things that we can actually test. God may have done it. God may have set the world in motion. God may have set the laws in place. God may intervene in ways that we can't detect. That's a metaphysical notion, though … that's a religious notion. And that's something that science just can't get at. And that's really the difference here. Science has to constrain itself in this way; those are the ground rules. And what creationists hope to do is to change the ground rules of science and to reintroduce supernatural explanations into science. That's the thing that disqualifies it right off the board.
Science Is Not Dogmatic
Creation scientists and intelligent-design creationists have always had the same kind of rhetorical strategy. One is to put themselves forward as science, the other is to say science itself is a religion. And the terminology that would be used would be to liken scientists to the priests—to say that evolution is dogma, to say that scientific materialism is the established religion of the 20th century. This is just a false charge. If you understand the difference between science as a way of knowing—science as a methodology—it doesn't make dogmatic claims, either theistic or atheistic. It sets those aside.
Evolution is portrayed by creationists as being equivalent to atheism. But that's not part of the definition of evolution. Evolution is just what we have discovered empirically using the normal scientific approach. One can set aside the question theologically about what that means; that's to depart from science itself. That's to bring in religion, to bring in philosophy—I'm certainly not opposed to any of that as a philosopher of science. But it's important for us to keep those things distinct conceptually. Science itself, when done properly, isn't dogmatic, isn't religious. It's just a way of investigating the natural world, in the best way that we natural beings are able to do it.
Science Tests Its Claims
Basically, what intelligent design is, is a claim that evolution can't explain things, therefore they win by default. That's not a scientific view. Science makes its decisions by testing its claims, not just by accepting them because they sound good. So, because we have to test our claims, we can only use natural claims, because natural claims are the only ones we can test. Natural claims are the only ones that we can hold constant variables for. They are the only claims that we can control variables for. You can't control for the effects of God.
If you teach intelligent design as a science, you are confusing students about the nature of science, about science as a way of knowing, the scientific method. You're also confusing students and miseducating students about the position of evolution within science.
Evolution is no more controversial in modern-day science than heliocentrism—that the planets go around the sun. There are individuals out there advocating geocentrism—that the sun goes around the Earth. But we don't give them equal time in the high school science class just because it's fair.
The Power of Science
I live in the realm of testability and prediction. If I can't make a prediction based on an idea, or if I can't falsify a theory based with that, it doesn't exist to me as a scientist. What makes a scientific idea special is that they're continually tested against the real world. And not every idea can do that. Not every idea, no matter how beautiful, qualifies as science.
It's really important to me that the public understand evolution, because there's great power in scientific knowledge. Evolution is the centrally unifying concept for all of biology. It unifies observations as different as genetics and ecology and so forth. Evolution is not a theory in crisis by any stretch of the imagination. But, that being said, do we disagree about how evolution acts, even some of the mechanisms? Absolutely. That's the sign of a vital and successful theory. But does it mean we throw away scientific understanding altogether? No way, that would be a tragic mistake.
Scientific knowledge has a special place in our world because it's testable. It's something we always have to compare against the real world. And many of the great breakthroughs in our world are coming from science. Not only technology, but new understandings about ourselves, our bodies, our climate, our world, are coming from scientific information. If children are somehow shielded from all that, we're doing them a great disservice.