Monday, July 9, 2012

On skepticism

Skepticism has a long proud history
Skeptics may get bad press, but they aren't just curmudgeons with nothing positive to say!  And we're not the only ones who believe this -- Kyle Hill with the James Randi Educational Foundation is working hard to get the word out, as he explains in his recent blog post

We have just listened to the latest (week of July 4) installment of the BBC Radio4's "In Our Time", on the subject of 'skepticism'.   This is the best radio program in the world, to our knowledge; it's like getting a university education, painlessly, easy to digest, free--and without exams!

But back to today's topic.  Skepticism is related to doubt, but historically the range of what that word means has been extreme.  The term has involved philosophical views that go back (in the western tradition, at least) to the classical Greek philosophers, and even there it was disputed.  There is no consensus about what the word or idea means.  Often it has to do with religious doctrine or ideas about the nature of the world, or today to what we call science--these areas not always distinct aspects of human endeavors the way we think of them today.

On one extreme, skeptics often argued that we can never, ever know what the world is like or even if it exists outside our own perceptions.  Maybe everything is just in our heads, or we're limited in how our sensory and mental abilities could possible know its ultimate nature.  On the other hand, skepticism has meant carefully checking claims about the world, to make what we think we know as solid as possible.  So skepticism can mean careful examination of claims so as to get one's best understanding of a real world out there....or it can lead us to throw up our hands and just say we don't ever know anything for certain, and so we must find 'tranquility' in life by not even trying to know anything or make judgments about it.

In the middle ages and subsequently, one view was that we must be skeptical of everything, doubting any claim, which led to the only conclusion which was that one must rely on faith.  That supported religious doctrine for many.  But to others, one should be skeptical of everything that was claimed, which would lead you to be deprived of faith!  Thus, historically, religion was not clearly helped or hurt by skepticism.

Starting roughly in the renaissance period, what we now call science developed as a methodical attempt to understand the ultimate properties of the world: what are matter and energy really like?  Are there 'laws' of nature, and if so how did they originate?  To others, science means more humbly attempting to find what is at least knowable in the sense of letting us manipulate the world or predict things. Whatever the ultimate truths, at least reality seems to have patterns and we'd like to know at least approximately what they are.  Practicality not perfection is the goal.

One question that relates to science is whether we can be confident that the patterns in nature that we have observed in the past will be observed in the future.  Is there any reason to believe in the continuity of nature?  Or, if one wants to skip that question, how much of the pattern we see today is regular enough that we can believe it will be that way tomorrow--even if our understanding is only approximate?

Philosophically, one simply cannot know the ultimates, perhaps.  But we can (and many would say in practice must) assume regularity, and live life according to what our senses let us perceive.

In all these discussions and debates by leading thinkers--from classical Greece to the present, religious, philosophical, scientific, or just ordinary people wondering about existence, skepticism has had to do with when to accept or how to resist dogma, and where that leaves us.

Skepticism is not nihilism!
The ultimate skeptics might have been nihilists, basically denying everything that is claimed.  But most people, even most skeptics, are not just reflexive nay-sayers.  When it comes to science, thinkers going way back realized that we might as well assume that the world is real and see what we can learn about it given that unprovable assumption.  This has led to the formulation of broad theories about nature.  How much of such theories should we accept as true, and when and where should we question them?

Science is supposed to be the one place where dogma is definitely not acceptable. We routinely say our job is to be skeptical of everything, always trying to prove our ideas wrong.  A 20th century philosopher Karl Popper explained this attitude by saying that perhaps we can never prove something to be true--an ultimately skeptical statement--but we can at least prove an idea or theory to be false. How do we do that?  We set up careful experiments or studies to explore an idea and when the study doesn't support it, we say we have falsified the idea.  Over time, as we thus remove one hypothesis after another, we whittle away at what isn't true and, as Sherlock Holmes would say, what's left must be more likely true.  Falsifiability is what scientists routinely say they subscribe to, diligently trying to prove themselves wrong.  But that is self-congratulatory baloney, because the truth is very different.

Experiments may look as if they're trying to prove something wrong, but read almost any paper and you'll see that what is really being reported is evidence of what is claimed to be true.  Further, most scientists may be unaware that falsifiability has fundamental flaws as a theory about theories and knowledge.  You may not support your hypothesis in your experiment, but that may not be because your idea was wrong, but because you had a flawed experiment, or at least that's what you tell yourself.  It is such things that allow science to build, and then cling to, wrong ideas.  And that means theory not wholly supported by data.  And that means dogma, the very opposite of scientists' self-proclaimed skepticism.  Science is just as dogmatic as anything else, as it turns out.

So where is the place for skepticism?
In fact, proper skepticism means questioning, not dismissing, ideas that are advanced about the world. It doesn't mean being negative or accusatory except where dogma is being asserted against what we know to be facts.  It means pointing out where stories being told about some aspect of nature--in our field, this would be genetics or evolutionary aspects of life--are being told to support theory that doesn't hold up as sound theory.  And, as we've blogged before, when evidence is statistical, inferences made on the basis of assumed probabilities, we need to be even more circumspect, because statistical analysis lays other sets of assumptions on the phenomenon that have nothing to do with it directly--for example, whether it's physics or genetics, assuming that what is observed could be repeated many times (see earlier posts of ours, such as recently on the Higgs Boson).

Evolutionary reconstruction is rife with reasons for doubt, because it's so often based upon minimization of the probabilistic aspects of nature and assumptions about the determinative role of natural selection.  And modern genetics, such as, yes, GWAS that we write often about but also many other areas, assumes strength of causality of individual genes that is far greater than what we actually know to be the general case.  Marketing and advocacy are all over the place in these areas.  There may be reasons for that, but it's not science, and whatever else it is, it's the opposite of skepticism--it's much more like dogma.

To critique claims about genetic causal structure related to, say, diabetes or why people behave as they do or why we walk upright, is to do the right thing, so long as one is dealing with what the actual evidence does or doesn't show--that is, so long as the questioning is not about scientists' honesty or character.  Those kinds of things may deserve criticism, but that's different from skepticism.

Dogma is practically and, especially, psychologically much, much easier than real, constructive skepticism, which is the opposite of nihilism.  Proper skepticism accepts that the world does in fact exist, and that there are some ultimate truths that we may never know.  But its premise is that we should give up dogma in our search to understand what we can of the world we live in.


Anne Buchanan said...

In a very nice illustration of why skepticism is important in science, the arsenic bacteria story of 18 months ago has been refuted by scientists who questioned the results and replicated the experiments, with different results. The papers are now online in Science. Here's a nice discussion.

Manoj Samanta said...

Good post !

If I write a commentary describing why we should be skeptical about global warming/climate change claims, will you publish it in your blog?