It has long been pointed out that science is only temporary knowledge in the sense that, as we quoted in an earlier post, every scientist before yesterday has been wrong at least to some extent. As Galileo observed, rather than being true, sometimes the accepted wisdom is the opposite of the truth--he was referring to Aristotle, whose views had been assumed to be true for nearly 2000 years.
Scientific theory provides a kind of parable of the world, a simplified story. That's not the same as the exact truth. Here is a cogent bit of dialog from JP Shanley's play Doubt, referring to a parable the priest, Father Flynn, had used in a recent sermon:
Sister James: "Aren't the things that actually happen in life more worthy of interpretation than a made-up story?"
Father Flynn: "No. What actually happens in life is beyond interpretation. The truth makes for a bad sermon. It tends to be confusing and have no clear conclusion."
Darwinian theory is like that. The idea that traits that are here today are here because they were better for their carriers' ancestors than what their peers had, is a tight, taut, and typically unfalsifiable kind of explanation. Since what is here is here because it worked and what did not work is not here, this becomes true by definition. It's a catch-all 'explanation'. It at least has the appearance of truth, even when some particular Darwnian explanation invokes some specific factor--often treated from Darwin's time to the present as a kind of 'Newtonian' force--that drove genetic change in the adaptive direction we see today.
That's the kind of scenario that's offered to account for the evolution of flight to capture prey, showy peacock feathers to attract mates, protective coloration to hide from predators, or why people live long enough to be grandmothers (to care for their genetic descendants). Some of these explanations may very well be factually true, but almost all could have other plausible explanations or are impossible to prove.
Simple, tight, irrefutable but unprovable stories like these are, to varying but unknown extent, parables rather than literal truth. Unfortunately, while science often (and often deservedly!) has little patience with pat religious parables that are invoked as literal truth, science often too blithely accepts its own theories as literal truth rather than parable.
We naturally have our own personal ideas about the nature of life, and we think (we believe) that they are generally true. They are sometimes different, as we try to outline in our book and in these postings, from what many others take for granted as truth. Strong darwinian selectionism and strong genetic determinism, in the ways we have discussed, are examples.
It may be difficult for people in any kind of culture, even modern technical culture, to be properly circumspect about their own truth-stories. Perhaps science must cling to theories too tight to be literally true, by dismissing the problems and inconsistencies that almost always are known. Accepted truths provide a working research framework, psychological safety in numbers, and the conformism needed to garner society's resources and power (here, among other things, in the form of grants, jobs, publications).
In fact, as a recent book by P. Kyle Stanford, Exceeding Our Grasp (Oxford Press, 2006) discusses at length, most theories including those in biology are under-determined: this means that many different theories, especially unconceived alternatives to current theory, could provide comparable fit to the existing data.
We can't know when and how such new ideas will arise and take their turn in the lore that is science. But in principle, at least, a bit more humility, a bit more recognition that our simple stories are more likely to be parable than perfect, would do us good.
Good parables do have semblance to plausibility and truth. Otherwise, they would not be useful parables. As we confront the nature of genomes, we see things that seem to fit our theoretical stories. In science as in other areas of human affairs, that fit is the lure, the drug, that draws us to extend our well-supported explanations to accept things as true that really are parable. We see this all the time, in the nature of much that is being said in genetics these days, as we have discussed.
Probably there's a parable about wisdom that could serve as a lesson in this regard. Maybe a commenter will remind us what it is!