Science is not as certain as some of us may think: that is the message of an article in last week's New Yorker, by Jonah Lehrer: "The Truth Wears Off: Is there something wrong with the scientific method?" (sub. required).  This brings both Karl Popper and Zhunagzi to mind.

Popper is not nearly as skeptical as Zhuangzi, and Lehrer notes that Popper "… imagined falsification occurring with a single, definitive experiment…", which turns out to be a tad too simplistic.  But the Viennese thinker gave us the notion of science as conjecture, which can, and perhaps should, encourage a certain humility regarding the empirical standing of any statement. 

In any event, the thrust of Lehrer's article is that there is a tendency for the results of scientific research to weaken as particular studies are replicated, which he calls the "decline effect."  In other words, when what appear to be established "truths" are subject to repeated experimental scrutiny their evidentiary support erodes.  And so, he writes:

"But now all sorts of well-established, multiply confirmed findings have started to look increasingly uncertain.  It's as if our facts were losing their truth: claims that have been enshrined in textbooks are suddenly unprovable. This phenomenon doesn't yet have an official name, but it's occurring across a wide range of fields, from psychology to ecology…"

Our facts are losing their truth – enter Zhuangzi.  He might say our facts never had the truth we ascribed to them.  The distinctions we draw to create theories that invest facts with meaning are, to Zhuangzi, artificial devices that obscure as much, if not more, than they elucidate: "Those who divide things cannot see."  And the language we employ to describe and explain fails to capture the fullness and complexity of the realities that surround us:

The spoken isn't just bits of wind.  In the spoken, something is spoken.  But what it is never stays fixed and constant.  So is something spoken, or has nothing ever been spoken?  People think we're different from baby birds cheeping, but are we saying any more than they are?

Zhuangzi would never have accepted scientifically established theories to be fixed and constant, which is just about where Lehrer is coming down:

"Such anomalies demonstrate the slipperiness of empiricism.  Although many scientific ideas generate conflicting results and suffer from falling effect sizes, they continue to get cited in the textbooks and drive standard medical practice.  Why?  Because these ideas seem true.  Because they make sense.  Because we can't bear to let them go.  And this is why the decline effect is so troubling.  Not because it reveals the human fallibility of science, in which data are tweaked and beliefs shape our perceptions. (Such shortcomings aren't surprising, at least for scientists.)  And not because it reveals that many of our most exciting theories are fleeting fads and will soon be rejected. (That idea has been around since Thomas Kuhn)  The decline effect is troubling because it reminds us how difficult it is to prove anything.  We like to pretend that our experiments define truths for us.  But that's often not the case.  Just because an idea is true doesn't mean it can be proved.  And just because an idea can be proved doesn't mean it's true.  When the experiments are done, we still have to choose what to believe."

I can hear Zhuangzi now: "You mean you're only now realizing that there are no answers?" (105)