Uncertainty, Creationism, Science

So--young-earth creationist evangelicalism loves "science" but hates uncertainty.

By "science," they seem to mean inductive examination of readily apparent data or details--e.g., how does the bombardier beetle's defense work? Such examination, in their view, properly yields solid facts about the world, facts which of course reveal the grandeur of God. Evolutionary theory, in this view, is not proper science because it functions not as a readily apparent fact or set of facts but as a provisional, revisable explanation of the data. To the creation scientist, evolution is a "guess" unproven by data, a guess that unscientifically biases the interpretation of available data and immorally contradicts the grandeur-of-God conclusions.

Thus we have the common anti-evolutionist attack that evolution is "only" a theory.

Now, mainstream scientists from any number of fields can (and have, and do) marshal a great deal of evidence to demonstrate that evolutionary theory (and other scientific theories that contradict a "young earth") is well supported by data from numerous studies. A number of anti-evolutionist scientists respond with detailed criticisms of such evidence. Evolutionary scientists respond with even more detailed counter-criticisms, and so on. Such back-and-forth barrages of evidence and criticism have historically sucked up a lot of air in late-twentieth century creation-evolution debates.

Two quick observations about such data wars: First, in no way do I suggest that these wars feature evenly matched opponents. Evolutionary theory in general enjoys broad consensus across scientific fields. What do I mean by "consensus"? I mean that, in pretty much any center of scientific research and teaching, the basic validity of evolutionary and other "old earth" theories is not an active question. Certainly, areas of revision and debate within such theories exists, but (as I will argue later), this is qualitatively different than saying there's ongoing doubt about whether evolution in general (versus, say, young-earth creationism) holds water. For all intents and purposes the old universe, evolutionary model is the only game in town. Science-based opponents of evolution are by comparison few and far between (though there are certainly more of them now than ever before).

Second, although the data-war debates often (and very quickly) become more super-specialized than my training allows me to follow, at no point do the anti-evolutionists get any closer to winning my support for the young-earth creationist case. Certainly my trust in the mechanisms of scientific-scholarly consensus has something to do with this. But more compelling is the fact that all this anti-evolutionist effort goes into attack. Historically, very little young-earth creation science research or writing presents positive propositions of its own. Where's the proof for a young earth as described exactly in Genesis? Would an objective examination of available non-Biblical data lead to a young-earth conclusion?

In other words, even if anti-evolutionists were successful in undermining evidence for evolution, it does not follow that young-earth creationism is therefore correct. Remember, science (for young-earth creationism) isn't about a theory or model about which you find some support. It's about discovering positive, absolute truth derived directly from readily available data. To meet its own definition of science, the young-earth model would have to function as the only logical conclusion from all data currently available. But very little in the creationist library advances any such claim. At best, young-earth creation science strains to offer mechanisms that might conceivably explain how, for example, light from stars seven million light-years away could possibly have reached earth in 6,000 years (the current favorite? "gravitational lensing"). This is a far cry from the plain-and-sure Truth standard to which creationists hold evolutionary theory.

But ultimately the data wars overlook a crucial point: science isn't about discovering Truth. In the early twentieth century, Karl Popper famously argued that science doesn't tell the story of small facts leading to big, certain truths. It's instead, he writes, a process of provisional explanations--hypotheses and theories--being repeatedly challenged by experiments that try to disprove them. Unassailable scientific theories do not exist. Indeed, any truth statement that presents itself as unassailable by definition fails to be scientific. In Popper's view, all legitimately scientific statements are falsifiable though experimentation. The best theories are at minimum those that withstand repeated experimentation without being falsified.

Since Popper's time, other historians and philosophers of science have challenged and modified Popper's standard. The best scientific models and theories, for example (I draw here on Michael Ruse's arguments), aren't merely falsifiable; they're also (among other things) predictive, productive, and consilient. That is, scientific models accurately predict yet-to-be discovered objects and phenomena, they inspire new kinds of experiments and new directions in research, and their explanations and predictions jibe with those of other fields' scientific theories.

Most importantly, however, scientific statements and models are tentative. Few scientists would claim that their theories are the final, complete, total word on any subject. Here the writings of science philosopher Thomas Kuhn prove especially valuable. Kuhn wrote that "normal science" within a particular discipline (say, astronomy) tends to operate under a single prevalent explanatory model, a paradigm. That paradigm, like any scientific model, opens certain avenues of experimentation and research while leaving others unexplored. For centuries, the Ptolemaic model of the universe (earth at the center, with the heavenly bodies orbiting around it) ruled.

Evidence that appears to dispute the dominant paradigm gets explained via additions to or elaborations of that paradigm. At times, for instance, Mars appeared to observers to travel backward for a bit (traveling in retrograde) before resuming its normal course across the sky. Operating under a Ptolemaic paradigm, medieval astronomers simply (well, not simply) added "epicycles"--revolutions within revolutions--to their model.

Finally, Kuhn, argues, paradigms so stressed become vulnerable to challenge by a radically new and contradictory paradigm, such as the Copernican or (later) Galilean models of a heliocentric solar system. Paradigm shifts change what "normal science" in a particular field is. Avenues of inquiry and experiment once open become closed off; previously unexplored ones open. Previous data gets re-interpreted through the lens of the new (and generally superior) paradigm.

Kuhn has his detractors, but few historians or philosophers of science would dispute that science involves revisable claims, not final truths. It is in the nature of science, in other words, to be uncertain.

More tomorrow,

JF