Gopnik on Popper

Some time back, we examined the fraught subject of academic discipleship  in this essay:

Chomsky, Freud, and the Problem of Acolytes

And now this postscript:

In The New Yorker for 1 April 2002,  Adam Gopnik recounts his pilgrimage, while still a grad student, to  the home of the philosopher Karl Popper, living in prickly retirement (the article is titled “The Porcupine”) in the English countryside:

Many years ago, when I was young and still in search of wisdom,  I went on a pilgrimage to meet the man I thought was the wisest in the world.

The sage’s relations with his philosophic colleagues  had  for long  been far from collegial;  indeed, the occasion for Gopnik’s publishing his meditation now, was the appearance of a book built entirely upon the long-ago incident of Wittgenstein threatening Popper with a poker (presumably upon the theory that “this tutorial room is not big enough for two philosophical prima donnas!”).  In his long talk with Gopnik, Popper denied he had ever received any useful criticism from colleagues.   And as for acolytes:

He smiled sadly.  “All of my students are attacking me now.  Three of my students, all of them I helped to get positions, to get chairs, and they know this, and still they attack me personally.  You know, when you do things for people, there are two types of reactions.  There are those who cannot forget you for it, and those who cannot forgive you for it.”

Gopnik ends his essay with a bravura what-if:

Had Jesus invited a few Pharisees over for the Supper … it might not have been his last.  Dining with disciples is a perilous business.

Pop ! goes the Positivist

 [This is a continuation of a thread begun here.]

Another example of fetishizing the visible (cf. now also this)  occurs in Karl Popper’s Conjectures and Refutations: the Growth of Scientific Knowledge (1962; page refs. to the Harper paperback reprint), p. 284:

In the last pages of Testability, Carnap discussed the sentence ‘If all minds should disappear from the universe, the stars would still go on in their courses.’  Lewis and Schlick asserted, correctly, that this sentence was not verifiable.

They so asserted incorrectly.  After all, we have a pretty good handle on those stars in their courses, beginning from not long after the Big Bang  through the present, during most of which there were no human minds.

And here’s a simpler experiment:  Let’s all just refrain from observing the moon for the next two weeks.  Now we open our eyes.  Surpri-ise!  Right where we expected to find it, and at a phase two weeks more mature than when we last checked (rather than the phase as last seen).

One occasionally observes a very young child shut her eyes and announce in a sing-song: “Youuu ca-han’t seee mee….!”  I doubt the child actually believes that, it’s just fun to say.  But suppose she did. She is then entertaining an erroneous optical theory, but not an erroneous ontological one.  She imagines that the lights went out for you as well; but she never entertains the thought that you yourself have been extinguished, or been transfixed into some mute deaf motionless limbo until such time as she shall be pleased to gaze again – after all, she has just shown this, by addressing you.

Incidentally, the whole Schlick-shop with its merry/morose band of logical positivists, appear to have created enormous problems for themselves, and come up with completely counter-intuitive results, from the basic motivation of wishing to exclude all metaphysical propositions from the outset as strictly meaningless.   (The story here is in line with our overarching defense of theism.)  In other words, it wasn’t enough to denounce as wholly unconvincing,  all purported metaphysical statements hitherto; nor to brand it a particularly uninteresting language-game; nor to marginalize the enterprise with the derision usually reserved for circle-squarers.  Metaphysics as such, and for all time, had to have a stake driven through its heart, the stake itself consisting in pure reasoning from selbstverständlich  (metaphysically a-priori? God-given? -- oops, NOT) first principles.  For a demonstration of the absurdities that apparently resulted, cf. Popper, passim.  As (p. 281, op.cit.)

My criticism of the verifiability criterion has always been this: against the intention of its defenders, it did not exclude obvious metaphysical statements, but it did exclude the most important … of all scientific statements … the universal laws of nature.

Why even go near such a disaster, for the sake of excluding-in-principle all metaphysical statements – which they were ignoring anyway?  Popper goes so far as to hazard a guess in a footnote to p. 175:  “One not need believe in the ‘scientific’ character of psycho-analysis (which, I think, is in a metaphysical phase) in order to diagnose the anti-metaphysical fervour of positivism as a form of Father-killing.”  (Note, b.t.w., the capital initial of “Father”.)

*

Since we were obliged, a moment ago, to deprecate Popper, let us hasten to another example, in which we find him on the side of the angels.  First let us note:

             * Our conduct is guided by moral laws.

             * Our scientific activity is guided by metaphysical principles.

             * Both categories are philosophically vexed, and any concrete application of these laws and principles may prove problematic; but we cannot do without them.

            Here is Popper (p. 287) characterizing the logical positivists: “They implicitly accept the rule: ‘Always chose the most probable hypothesis!’  He goes on:

Now it can be easily shown that this rule is equivalent to…’Always choose the hypothesis which goes as little beyond the evidence as possible!’  And this, in turn [amounts to] ‘Always choose the hypothesis which has the highest degree of ad hoc character!’

an undesirable result for science.   (Cf. Chomsky, passim, re the extraordinarily abstract and roundabout way you may have to proceed  to get valid results, by no means simply tip-toeing a bit beyond “the evidence”.)

            The principles which we require instead  may be best illustrated by an old joke (presented here in a slightly revised form):

     A zoologist, a mathematician, and a positivist  are touring the hinterlands of Bohemia by train.  Through the window they spot, standing motionless at some distance, a purple cow.

     “Fancy that!” exclaims the zoologist. “There are purple cows in Bohemia.”

     The mathematician, in a low voice, amends: “There is at least one purple cow in Bohemia.”

     The positivist, raising his finger, crisply corrects to:  “In Bohemia there is at least one cow, purple on one side.”

            The joke is that the positivist has the most precise view of the evidence; and of the three statements, only his own is certainly true (interpreting an unmodified “purple cow” in the natural way, as “purple more or less all over”); yet his scruples are absurd.  Science would not progress, were it bound by such fragmented literalism.  (Indeed, we should have to replace “cow” with “an apparently bovine organism”, and always assuming that we can rule out a mirage, or a collective hallucination, or some effect of swamp gas; or for that matter an analogue to one of Hilary Putnam’s pet entities, the Mechanical Cat from Mars.)  And we would have to gloss Quine’s celebrated interjection, gavagai!, as possibly:  “Lo, a rabbit-stage, seen from the east.”

(For more on bovine mathematics, see "How Now, Round Cow".)

A gathering of Positivists

Note:  Occasionally one meets with such unilateral positivist agnosticism  in a non-jocular context:

Franz Ferdinand rode erect, his visible foot deep in the stirrup, a saber at his side.

-- Robert D. Kaplan, Balkan Ghosts (1993), p. xxvi

The above scenario has been much discussed among epistemologists, under the rubric “Henry and the barn façades”.   However, the cow version is much funnier.

Ceci n’est pas une grange 

~

To move from this to an outlook useful for science, we need these metaphysical principles:

   (1) a certain uniformity or self-cohesion to nature

   (2) the reliability (not in a logical, but in a practical sense) of induction.

(There are others, of course, such as the usefulness of deduction;  but that applies in every world, not just in this contingent one.)

            Now, both these principles are of vexed and delicate application; as are, indeed, the Commandments.   Just as it is difficult to avoid situation ethics, I see no way around a kind of “situation metaphysics”.   The zoologist, using these principles, together with his discipline-specific knowledge (to the effect that animals generally come in species, not as singletons), concludes the presence of purple cows.  But here I must side with the formulation of the mathematician: there is at least one such cow, but perhaps no more.  For, nature’s uniformity depends on the domain.  Were an experiment ever to identify, say, a Higgs boson, we should conclude the existence of an emphatic plurality of Higgs bosons; that there should only be one in the universe, is inconceivable.  But biology is more mottled than that.  Given our collective prior acquaintance with hundreds of thousands of cows, none of which was ever purple, we would hypothesize here an extremely rare mutation for (bilateral) purple (bilateral because bilaterally symmetric animals generally continue to evolve with bilateral symmetry, pace the occasional narwhal).  Since a cow delivers but a single calf at a time, this one has no identical siblings, so it is probably unique.  Moreover, the bulls will likely shun her for her color, and she shall have no offspring.  The mutation dies with her.

Carnap attempts to avoid the assumption of a metaphysical principle, by declaring (1) to be “analytic” (i.e., more like “2+2 = 4” than like “animals tend to come in species” or “each elementary particle is invariable within its class”).  Popper comments (p.289) that “no such principle of uniformity can be analytic (except in a Pickwickian sense of ‘analytic’)."  In fact, we noticed, the principle is nothing remotely like analytic, having always constraints on its application, which in some domains may be severe.  And as for (2), I concur with Popper (p.292) that it is “a principle of a priori metaphysics.”  And none the worse for that.

[For further notes on ineluctable metaphysical underpinnings of the scientific enterprise, see here.]

Truth Decay

The empirical character of a very successful theory  always grows stale, after a time.  We may then feel (as Poincaré did with respect to Newton’s theory) that the theory is nothing but a set of implicit definitions or conventions …

-- Karl Popper, “Truth, Rationality, and the Growth of Knowledge”, repr. in Conjectures and Refutations: the Growth of Scientific Knowledge (1962; page refs. to the Harper paperback reprint), p. 240

I’m currently reading The Shape of Inner Space, by Shing-Tung Yau -- the Yau of Calabi-Yau, which lies at the heart of string theory.    Unlike Smolin’s The Trouble with Physics, let alone Woit's Not Even Wrong, the author is not out to debunk the theory in any way, especially as he was one of its mathematical progenitors:  nor to puff it, like Brian Greene, since  unlike those contentious authors, Yau is not a physicist by trade, but a pure geometer.  But towards the end of the book, he is led to exclaim: 

Given that much of string theory now hinges on compactifications of Calabi-Yau manifolds, which have these moduli with their associated massless scalar fields  and particles that don’t appear to exist, is string theory itself doomed?

And he quotes physicist Burton Richter against those quasi-nihilistic latitudinarians who have (as a recourse of despair) embraced “the landscape” (short version:  Anything Goes):

To them the reductionist voyage that has taken physics so far has come to an end.  Since that is what they believe, I can’t understand why they don’t take up something else -- macramé, for example.

There have, throughout history, been repeated instances of premature prophecying of “the End of Physics”:  but  there   the idea was that we were close to having solved everything;  never, that physics might one day become permanently stuck.

*

It was with these passages ringing in my mind, that I picked up Jonah Lehrer’s essay in the current issue of The New Yorker:  “The Truth Wears Off”.   I won’t summarize it -- it is brilliantly written, go read it -- but merely comment that the widespread scientific predicament there depicted -- in physics and biology and psychology and beyond -- seems even worse that the slightly softened interpretation that the author tries to present as a possible explanation or compromise.   Neither “happenstance” nor unconscious bias  can explain the range of what is supposedly going on.  E.g. the researcher who repeatedly failed to replicate his own results, not for want of trying, should  if anyone  have been prey to such bias.

[Cultural comment, to be developed if anyone’s interested:  the scientific standing of Rhine’s experiments in ESP.
-- Indeed, this just in:
http://www.nytimes.com/2011/01/06/science/06esp.html?ref=global-home&pagewanted=print  ]

*

As Pauli wrote to Kronig in 1925:
"At the moment, physics is again terribly confused.  In any case, it is difficult for me, and I wish I had been a movie comedian or something of the sort, and had never heard of physics."
Or cosmologist Edward Harrison in 1975, saying that endless expansion "would make the whole universe meaningless.  If that were true, I would quit, and spend my life raising roses." 

*

There is a thread, a thought, that links these observations;  but  once again -- Wovon man nicht sprechen kann, darüber muss man schweigen.

*

The Shape of Inner Space is something of an intellectual autobiography, in addition to an overview of Calabi-Yau.  And quite an engagingly modest one, as these things go.   By the end of it, you have a comfortable familiarity with the author, and are full of friendly feelings.

Immediately after finishing it, I happened to re-skim George Szpiro’s equally well-written volume, Poincaré’s Prize , and was startled to see that the sinister puppet-master depicted in the chapter “The Gang of Four, Plus Two”, is none other than Shing-Tung Yau.  When I originally read the book, the name meant nothing to me; but now… it was like rounding the corner, and encountering your own cousin brandishing a knife.

Now… in the grander scheme of things, so what;  we all have our faults.  But this account of academic rivalries  gibed with my surprise at searching Shape’s index for the name of Woit or Smolin, and not finding them.  Whatever their merits or demerits, these are popular recent book-length treatments of string-theory, and one might expect that Yau would reply to them, if only to rake them over the coals.  But only towards the end of his book  does he mention theirs, in briefest passing:  and then, without uttering their names (as one might be forced to allude to Mein Kampf, but draw the line at penning the name of its author).

Yau does, however, offer a kind of reply, as he demonstrates, pretty convincingly, that String Theory, the beneficiary of much math, has in turn created, and inspired, solid math in its own right, which will survive independently of whether the particular universe of our own sojourn  happens to embody the physics.   Indeed, the fact that Ed Witten received a Fields Medal, rather than a Nobel Prize for Physics, pretty much demonstrates that.

*

Addendum:

Pauli was not alone in his lament.   Schrödinger to Bohr, 1926:

If we are going to stick to this damn quantum-jumping, then I regret that I ever had anything to do with quantum theory.

And Einstein in 1924, re the idea of renouncing strict causality:

I would rather be a cobbler, or even an employee in a gambling house, than a physicist.

This is rather a rarified kind of job-dissatisfaction.  It is as though a carpenter, towards the end of a long and successful career, were to cry out, “Had I known that wood is mere cellulose, rather than a habitation for dryads,  I would have preferred to have been anything -- a plumber or a physicist -- rather than this!”

But the phenomenon does exist.  The author in which I found those two quotes -- J. C. Polkinghorne, The Quantum World (1984), p. 53 -- after a distinguished career as a particle physicist, resigned his chair, and became a vicar in a country parish in Kent.  It was from this Father-Brown-like living that he published his popular little volume with Princeton University Press.

Similar instances could be cited, notably Alexander Grothendieck.  (Motif: “Goodbye to All That.”)

 

[Update Feb 2014]  A statistical reason for “truth decay”, with examples:

Most scientists would look at a P value of 0.01 and “say that there was just a 1% chance” of the result being a false alarm. “But they would be wrong.”

Rather than being convenient shorthand for significance, the P value is a specific measure developed to test whether results touted as evidence for an effect are likely to be observed if the effect is not real. It says nothing about the likelihood of the effect in the first place.

http://www.nature.com/news/scientific-method-statistical-errors-1.14700