The first part of this series can be found here.
My blog about the importance of taking scientific consensus seriously generated some heated response from several directions, most noticeably over at Uncommon Descent, the Intelligent Design blog run by William Dembski. This is a critically important issue for the Intelligent Design community because its whole approach to origins requires that it set aside scientific consensus in favor of alternative views accepted by less than 1% of practicing biologists. ID requires that there be some criteria other than consensus for the evaluation of what constitutes “science.”
A variety of arguments are provided to support this, which I would like to examine over the next few months. I will start with the historical argument first.
Dembski writes: “If the history of science is any indicator, every scientific theory has faults and is eventually abandoned in favor of a better, more accurate theory. Why should we expect any different from evolutionary theory?”
I find it hard to understand what Dembski means by this. He speaks of every theory. If he had said some theories, he would OK. But every theory? Over two thousand years ago Greeks developed, to consider one example, a theory that the earth was round and not flat. Their reasoning was quite ingenious and included observations like the shape of the earth’s shadow on the moon during an eclipse, and the way a ship appeared to sink down as it sailed out to sea. This theory seems quite secure to me and unlikely to be abandoned. In fact this idea is now a simple fact, as photographed from space.
Two millennia after the enduring success of the round earth theory, Copernicus developed a theory that the earth was moving. To be sure, this overturned a theory that the earth was stationary, but are we really supposed to believe that the motion of the earth will be “eventually abandoned” in favor of a “more accurate theory”?
Let’s take a stroll through science and look at some of the central ideas: electrons and protons have equal and opposite charges while neutrons are uncharged; radio waves travel at the speed of light; the orbits of electrons are fixed to certain positions and cannot be anywhere in the atom; stars shine by fusing nuclei; the universe is expanding; disorder increases through time. These theories once seemed speculative and controversial but now they represent the consensus of the scientific community. Are we really being asked to believe they will one day be overturned?
The history of science does not suggest that theories are abandoned. Scientific progress occurs most commonly when theories are refined and extended. Physicists did not abandon Newton’s theory of optics in the 19th century--it was extended and refined with the discovery that visible light, radio waves and infrared radiation were all part of a continuous electromagnetic spectrum. Similarly, the “solar system” model of the atom was not abandoned when it was discovered that the nucleus had both protons and neutrons in it. And that nuclear model was not abandoned when it was discovered that protons and neutrons are composed of quarks.
So how about evolution? Is it reasonable to hold out hope that it will one day be abandoned? The situation with evolution is quite the reverse. Evolution has been around for over 150 years and remains within the broad outlines traced by Darwin in The Origin of Species. During that period it has become steadily stronger and more successful at explaining the natural world. When DNA was discovered, for example, it fit evolutionary theory exactly, confirming Darwin’s intuition about how natural selection had to work. And when the mapping of genomes of multiple species began a few years ago, the data confirmed the ancestral patterns that had been developed based on comparative anatomy and other approaches.
The consensus that exists now about evolution is close to 100% of research biologists. Comparative anatomists, geneticists, cell biologists, paleontologists, embryologists and every other sub-field of biology have all compared their data with each other and found that evolution ties it all together and makes it into a remarkably coherent system. This conclusion is so broad and based on so many different technical fields that I cannot imagine how a layperson could even begin to understand it well enough to decide that all these experts were wrong.
Thomas Cudworth, also on the Uncommon Descent blog, is appalled at my consensus argument, which he summarizes as “everyone should defer to the majority of evolutionary biologists simply because they are the certified experts.” Leaving aside the fact that “certified expert” is not a label in use in the scientific community, Cudworth is properly stating my position. A simpler way to put it would be like this, however: People who know a lot about a subject are more likely to be correct when they speak about it than people who know very little.
Is a challenge really being made to this statement? Are we really to believe that it is acceptable to put the conclusions of people who know very little ahead of those who know a lot? If I, a physicist who took my last biology class in 1975, decide to challenge Francis Collins on a question of genetics, should anyone listen to me, just because they like my “science” better? (Please don’t, if I go off the rails and do something like this.)
And why is this “everyman science” proposed only in the area of biology? Can we apply Cudworth’s argument to physics and astronomy? If I can find three trained astronomers who are absolutely certain that astrology is valid, does this mean we should consider setting aside the consensus view from tens of thousands of other astronomers who think the opposite? If I find three psychologists who believe the stories of alien abductions, does that idea become worthy of consideration? How about three historians who deny the Holocaust?
The sad truth of the matter is that the argument made against the validity of consensus in science is selectively applied only to evolution and only because the ID movement has no choice. Its confident predictions of a decade ago that evolution was tottering and would soon collapse have not come true. The consensus remains against ID and so the consensus must be wrong.