Midweek Perspecives: Keep the science in science class
Interesting ideas that can't be fully tested, such as intelligent design, must be set aside
Wednesday, December 29, 2004
By Richard Alley - Post Gazette
The school board of the Dover Area School District in York County voted in October to have so-called "intelligent design" included in the science curriculum as an alternative to Darwinian evolution, and although a lawsuit has been filed against this decision, similar mandates are being considered elsewhere. As a scientist and a religious person, I hope that school boards will avoid mixing apples and angels in science classes.
Like many scientists, I am fortunate to teach. We know that our students will soon discover things we missed, often correcting our mistakes in the process. Thus, a scientist would be foolish to claim that science gives absolute knowledge of Truth. If I successfully predict the outcome of an experiment, I'm never sure whether my understanding of the world is True, whether I'm pretty close but not quite right, or whether I'm really confused and was just lucky this time.
But our society has agreed to act as if science is at least close to being true about some things, and this makes us very successful doing those things. Carefully crafted bits of silicon really are computers, airplanes designed on those computers using principles of physics really do fly, and medicines from biological laboratories really do cure diseases. Science, tightly wedded to engineering and technology, really does work and is the best way we humans have invented to learn to do many things.
Science asks a high price for the value it gives, however, and that price is real dedication to science. For a plane to fly, for a medicine to cure disease, every step must be tested, and everyone else must be able to follow those steps. Science students are welcome to rely on divine inspiration, but they cannot rely on divine intervention in their experiments. Scientists, like athletes, must follow the rules of the game while they're playing.
What, then, are the rules? First, scientists search for a new idea, by talking to people or exploring traditional knowledge, or in the library or other places. We look for an idea that explains what we see around us, but that also disagrees with an old idea by predicting different outcomes of experiments or observations. Then we test the new idea against the old one by doing the experiments or making the observations.
An idea that repeatedly makes better predictions is kept; an idea that repeatedly does more poorly is set aside. An idea that can't be tested also is set aside; it isn't scientific. Even if I really love an idea, or really believe it is True, but I can't think how to give it a fair test, I have to set it aside for now. Some people find this limiting and avoid science; others find it exhilarating and are drawn to science. Doing this well gives us good things from good science.
Who decides what is or isn't science? Scientists -- with other thinkers watching over our shoulders -- do the day-to-day deciding, but ultimately the whole bill-paying, newspaper-reading community is checking on us to make sure that we really are producing useful insights.
Does science have limits? Will we run out of new ideas? Will we hit problems that we can't solve? Perhaps. But when I come out of a classroom of bright young students, I am convinced that we're nowhere near any limits that might exist, and that there is much to discover yet.
So, what about intelligent design, or even young-Earth creationism, and teaching them in science class? They're interesting ideas. But, some parts we don't know how to test. Even if they are said by scientists, they aren't science. And the testable parts have been tested and found wanting -- they don't do as well as the "scientific" view in explaining what we see around us, or in predicting what we find as we collect new tree-ring records and ice-core samples, or as we search for oil and valuable minerals, or as we watch dangerous new diseases appear faster than our bodies can respond to them.
The classes I teach spend a few hours discussing the main pieces of evidence, and a lifetime isn't enough to cover all the details, but scientists have been working on these questions for centuries and have a pretty good idea of what works. Evolution "in the dark backward and abysm of time" is scientific theory, not Truth, but it is very good science.
How does this fit into the bigger picture? Although some people are happy to view science as merely a tool, others do believe that the remarkable success of science means that we are getting closer to truth. But even these people sometimes disagree about that truth: a mechanistic universe, a benevolent and omnipotent deity or something else? Fascinating as they are, such questions are for now outside of science. Many scientists and religious people are thinking about such questions, but no experimenter knows how to guarantee the cooperation of an omnipotent deity.
By all means, students should ask deep questions, think and discuss and probe. Science does not tell us what we ought to do, and students will have to join us in addressing what ought to be as well as what is. But if we want to face the big questions with better medicines, with computers that function and planes that fly, with clean water and buildings that don't fall down, I believe that we should teach science in science class.
(Richard Alley is the Evan Pugh Professor of Geosciences at Penn State University.) |
