Pinker on science

In “Science is not your enemy” (permanent link), Steven Pinker starts an argument with humanist Leon Wieseltier. The humanities are a sinking ship, says Pinker, and need to re-conceive their relationship with the natural sciences. Let the two faculties fertilize each other! – No, thank you, says Wieseltier, we get along just fine.

It’s an exchange well worth reading. It picks up a thread going back at least to C. P. Snow’s identification of two cultures, scientists and humanists, which don’t understand each other. Since the time Snow wrote his little book (the 1950s), the situation hasn’t changed much. The two groups still surf along largely independent trajectories. But mounting voices demand that the humanities connect with the empirical methods of the natural sciences and start producing testable results instead of ever more free-floating theory.

Pinker doesn’t put his views in such stark terms. All he seems to offer is an invitation to open dialogue, but Wieseltier reads it as plan for usurpation. I think Pinker ultimately has the better arguments. Although the illumination science may bring to humanistic studies may be weak in places, there certainly is scope for substantial enlightenment (e.g. the science of sensory perception vs. the laws of aesthetics and the reception of art). Wieseltier’s a priori insistence that natural scientific approaches will be fruitless seems unnecessarily conservative. There’s nothing to fear (unless you have something to hide).

On the other hand – and that’s the subject of this post – Pinker’s picture of science is unduly optimistic. He talks about neurons, genes and big data a lot, and says about the enlightenment thinkers that he often longs “to travel back in time and offer them some bit of twenty-first-century freshman science that would fill a gap in their arguments or guide them around a stumbling block”. Mentioning neurons, genes, evolution and big data as the prime examples of scientific progress raises an internal flag with me, because these terms stand for exactly those disciplines whose findings are routinely exaggerated.

The neurosciences will change the way we think about ourselves? – Nope. Knowledge of our DNA sequence will revolutionize our understanding of human nature and the treatment of diseases? – Sorry, no. Adaptationist evolutionary explanations for everything? – Not likely. Big data revealing hidden patterns and allowing for a deeper understanding?- Not so far, and maybe never.

It is more than ironic when a scientist extolls the virtues of the natural sciences to a humanist and then doesn’t even get his science right. It happens to Pinker about halfway into the text, when he speaks of

deep and elegant principles, like the insight that life depends on a molecule that carries information, directs metabolism, and replicates itself.

 

Well, life depends on many molecules, and the idea that one of them is special in carrying information that directs development is as wrong as it is widespread. Surprising though it may seem, the notion that DNA contains the instructions to build an organism, a foundational principle for modern human genetics, is nothing but the unexamined import of a sexy term from communications theory into biology. Around the time Watson & Crick discovered the structure of DNA, geneticists started using the term “information” to describe what they thought DNA was doing: passing instructions into the cell, much like a computer   program that supervises its own execution. In time, scientists of all flavors, along with a fascinated public, uncritically accepted this metaphor. Since the 80s, it became a driving force for big biology projects like the Human Genome Project, gene therapy, and today’s personalized medicine.

I guess we can be thankful that someone eventually did examine the metaphor, but it was not scientists, it was philosophers of science. The verdict: there is no reason to believe genes possess the kind of information geneticists ascribe to them, namely instructions with semantic content. Such information has only been found in one place so far: the minds of human beings (and perhaps some other animals). To impute it to inanimate objects like bio-molecules is entirely unwarranted. And so it’s no surprise that the literature contains no serious defense of this kind of genetic information. But by and large, neither scientists nor the public seem to care or even have noticed.

Generally, Pinker is overly optimistic about what science knows. Here are some examples. He says that while

[t]he processes of life… used to be attributed to a mysterious élan vital; now we know they are powered by chemical and physical reactions among complex molecules.

He talks about

[t]he scientific refutation of the theory of vengeful gods and occult forces

and claims that

the findings of science entail that the belief systems of all the world’s traditional religions and cultures… are factually mistaken.

 

But I don’t believe science has refuted all these things. It merely doesn’t require them anymore. Modern theories of life, for example, have not shown that vitalism is false. Rather, increasing insight into the biochemical make-up of living cells has simply seemed to make the invocation of a vital spirit unnecessary. The molecules alone seemed very well able to do the job. But our actual theories of biological development are rudimentary at best, and this is only underscored by the fact that most scientists for most of the past few decades have been entirely content with the pseudo-explanation – shared by Pinker – that genes carry information to direct ontogeny.

More fundamentally, it is entirely possible that consciousness is tied to the phenomenon of life, and the best bet for consciousness currently is that it is irreducible to physics. If that is the case, at least one aspect of life cannot be explained by the usual reference to molecules, and something else akin to an élan vital might come into play.

God and occult forces have suffered a similar fate. They are not things that have been refuted by science, they merely are no longer required in order to do the science we currently do. For all I know, the evidence for God is probably non-existing and the concept is not needed to explain anything. But this doesn’t amount to a refutation. If God existed, with the abilities usually credited to him, it wouldn’t be hard for him/her to stay below the radar of science.

The case of “occult forces” or, more generally, paranormal phenomena is a bit different and more interesting. As far as I can see, the scientific literature as well as a large body of folklore on the subject are substantial enough to suspect that something as yet undiscovered may be at work.

Much of the public discussion on controversial phenomena, although seemingly concerned only with evidence, turns on the meta-theoretical principles of falsification and parsimony. Popper famously said that science cannot verify, only falsify, theories. If something is not falsifiable, i.e. not testable, it is not scientific. Paradoxically, sometimes this is taken to mean that some claimed fact is false because untestable. However, it only means science cannot say anything about the claim and the implied phenomenon.

This becomes relevant when concepts like e.g. ‘the supernatural’ are understood as defining a realm of phenomena inaccessible in principle to empirical testing. If someone endorses the reality of the supernatural thus defined, it is entirely appropriate to point out to them that this view is of no scientific interest. But the real challenge for science is to illuminate the nature of a cluster of phenomena that just happen to be unfortunately named “supernatural” or “paranormal”. Evidently, whatever turns out to exist is natural in the relevant sense.

The appeal to parsimony is a similar red herring. Skeptics may use Occam’s razor against non-skeptics in the belief that it invalidates their existence claims, but it does not. It’s true that the principle states that when faced with two explanations explaining the same thing equally well, one should choose the one that is simpler, i.e. postulating fewer variables. Thus, if you can explain the world just as well without as with God, you should go with the god-less explanation. But while this is entirely reasonable, it is also entirely pragmatic. Science would grind to a halt in no time if every alternative adding any number of gratuitous explanatory factors to the baseline theory would demand equal scrutiny. But the world, I imagine, does not care about parsimony. For all we know, there’s no reason to believe that among two equally powerful explanatory stories, the world would generally choose to implement the simpler one.

This all goes to show that falsification and parsimony are methodological, not ontological, principles. They do not work against claims of novel or non-standard phenomena. And they’re a far cry from a refutation of such phenomena.

Maybe Pinker is right when he says that

the worldview that guides the moral and spiritual values of an educated person today is the worldview given to us by science.

But then again, that worldview tells us much less than some science enthusiasts believe. This is not only because of the lack of ontological guidance to be gotten from meta-theoretical principles. It is also because the scientific process is not nearly as elegant as Pinker describes it:

[T]he defining practices of science, including open debate, peer review, and double-blind methods, are explicitly designed to circumvent the errors and sins to which scientists, being human, are vulnerable… [T]he cycle of conjecture and refutation is the lifeblood of science.

 

This is hardly a representative summary of how the natural sciences work. Sure, the elements Pinker mentions are an important part of science and they set it apart from other, less successful human endeavors like romantic relationships. But at least biology and medicine today are just as much governed by the logic of media and marketing and the capriciousness of trends. And the only cycles I see are hype cycles. There’s a lot of conjecture, but hardly any refutation. Instead, if ideas don’t pan out or simply go out of fashion, they’re tacitly abandoned without any systematic reflection. No lesson is learned.

Pinker thinks science illuminates

the deepest questions about who we are, where we came from, and how we define the meaning and purpose of our lives.

 

Yet, it’s hardly a coincidence that these are all questions to which science’s contribution is regularly overstated. The “who” question is typically answered by reference to the alleged deterministic powers of DNA and by some speculation on our hunter-gatherer past courtesy of evolutionary psychology. How we give meaning and purpose to our lives may, for some, be illuminated by science, but our lives are so much larger than science, and our purpose depends on so many things outside of it. It has been noted before: science might be able to tell us what is, but it cannot tell us what ought to be. The “where” question is the only one that, in my opinion, has received a truly fundamental scientific answer, one that shows the biological relatedness of all organic life through the process of evolution. On the other hand, our understanding of human evolution is still in its infancy given that one big chunk of it, the role of culture, is only now beginning to be investigated with some theoretical rigor.

Science is one of the greatest inventions of mankind. It is our best way of systematically acquiring knowledge about the world around us. At the same time, it is a human endeavor, and as such bound by the many limitations and imperfections of the fallible creatures that we are. It works not nearly as smoothly, and its results are not nearly as clear and unambiguous, as the current generation of science enthusiasts would like to believe.

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