« One more hurdle, cleared. | Main
July 26, 2006
Models, errors and the culture of science.
A recent posting on the arxiv:
On the Nature of Science by B.K. Jennings
A 21st century view of the nature of science is presented. It attempts to show how a consistent description of science and scientific progress can be given. Science advances through a sequence of models with progressively greater predictive power. The philosophical and metaphysical implications of the models change in unpredictable ways as the predictive power increases. The view of science arrived at is one based on instrumentalism. Philosophical realism can only be recovered by a subtle use of Occam's razor. Error control is seen to be essential to scientific progress. The nature of the difference between science and religion is explored.
Which can be summarized even more succinctly by George Box, famously saying "all models are wrong but some models are useful" with the addendum that this is what makes science different from religion (or other non-scientific endeavors), and the figuring out the useful bits is what drives science forward.
Jennings covers several of the important problems with external criticisms of science, including the God of the Gaps idea (1). Naturally, the problem with this approach to dealing with the statements that science makes is that gaps have a pesky tendency to disappear over time, taking that bit of God with them. From Jennings' perspective, this idea is just a special case of the more general "Proof by Lack of Imagination" criticism, which is summarized as "I cannot imagine how this can happen naturally, therefore it does not, or God must have done it." The problem for critics of science is that, more often than not, there have already been many people, much more imaginative than they, who have shown that the phenomenon in question (e.g., continental drift) does indeed happen naturally. For as yet unexplained things like, Why is the mass of a proton precisely such and such?, can we really presume that no one more clever will ever come along to answer it?
Evolution is, as usual, one of the best examples of this kind of attack. For instance, almost all of the arguments currently put forth by creationists are just a rehashing of arguments made in the 1800s against evolution. Indeed, Darwin's biggest critic was the politically powerful naturalist Sir Richard Owen, who objected to evolution because he preferred the idea that God used archetypical forms to derive species. The proof, of course, was in the overwhelming weight of evidence in favor of evolution, and with Darwin being much more clever than Owen in the end.
To scientists, this is all quite droll, being our bread and butter. But, to non-scientists, it is not the obvious way to accrue knowledge about how the world works. Jennings points out that prior to Galileo, knowledge was based on authority, either that of the Church or of Aristotle (who was better at logic than he was at science). It took Galileo to point out that Biblical predictions about the heavens disagreed with observations. I suspect that for most non-scientists, authority and truth are tightly intertwined, and that this might explain several curious problems with the lay public's understanding of science.
As I've been digesting Deborah Mayo's excellent (and I fear vastly under-read) Error and the Growth of Experimental Knowledge, it strikes me that the problem with science being a) poorly understood by the lay public and b) attacked by religious nuts at every turn, may be partially a cultural problem. In her reinterpretation of Kuhn's analysis of Popper, she divides science from non-science by arguing that non-sciences engage only in "critical discourse":
The practitioners of astrology, Kuhn notes, "like practitioners of philosophy and some social sciences [AC: I argue also most humanities]... belonged to a variety of different schools ... [among which] the debates ordinarily revolved about the implausibility of the particular theory employed by one or another school. Failures of individual predictions played very little role." Practitioners were happy to criticize the basic commitments of competing astrological schools, Kuhn tells us; rival schools were constantly having their basic presuppositions challenged. What they lacked was that very special kind of criticism that allows genuine learning - the kind where a failed prediction can be pinned on a specific hypothesis. Their criticism was not constructive: a failure did not genuinely indicate a specific improvement, adjustment or falsification.
In other words, critical discourse is a form of logical jousting, in which you can only disparage the assumptions of your opponent (thus undercutting their entire theory) while championing your own. Marshaling anecdotal evidence in support of your assumptions is to pseudo-science, I think, what stereotyping is to racism. So, since critical discourse is the normal practice outside of science, is it any wonder that when non-scientists attack science, they use the only form of criticism they understand? This observation, of course, leads me to be extremely depressed about the current state of science education in this country, and about the possibility of politicians ever learning from their mistakes.
(1) The God of the Gaps is basically the idea that science explains how nature works, and everything left unexplained is the domain of God.
posted July 26, 2006 11:26 PM in Scientifically Speaking | permalink