Special Circumstances

`I don't believe in natural science.'

From Incompleteness: The Proof and Paradox of Kurt Gödel, by Rebecca Goldstein. 2006. Norton paperback, ISBN 0-393-32760-4.

Though Princeton's population is well accustomed to eccentricity, trained not to look askance at rumpled speciments staring vacantly (or seeminly vacantly) off into space-time, Kurt Gödel struck almost everyone as seriously strange, presenting a formidable challenge to conversational exchange. A reticent person, Gödel, when he did speak, was more than likely to say something to which no possible response seemed forthcoming:

John Bahcall was a promising young astrophysicist when he was introduced to Gödel at a small Institute dinner. He identified himself as a physicist, to which Gödel's curt response was `I don't believe in natural science.'

The philosopher Thomas Nagel recalled also being seated next to Gödel at a small gathering for dinner at the Institute and discussing the mind-body problem with him, a philosophical chestnut that both men had tried to crack. Nagel pointed out to Gödel that Gödel's extreme dualist view (according to which souls and bodies have quite separate existences, linking up with one another at birth to conjoin in a sort of partnership that is severed upon death) seems hard to reconcile with the theory of evolution. Gödel professed himself a nonbeliever in evolution and topped this off by pointing out, as if this were additional corroboration for his own rejection of Darwinism: `You know Stalin didn't believe in evolution either, and he was a very intelligent man.'

`After that,' Nagel told me with a small laugh, `I just gave up.'

The linguist Noam Chomsky, too, reported being stopped dead in his linguistic tracks by the logician. Chomsky asked him what he was currently working on, and received an answer that probably nobody since the seventeenth-century's Leibniz had given: `I am trying to prove that the laws of nature are a priori.'

Three magnificent minds, as at home in the world of pure ideas as anyone on this planet, yet they (and there are more) reported hitting an insurmountable impasse in discussing ideas with Gödel.

Leave aside the comment about natural selection, and consider the other two anecdotal quotes attributed to Gödel. They are entirely consistent with Gödel's version of Leibniz's principle of sufficient reason; Gödel's so-called `interesting axiom' which is talked about earlier in Goldstein's book:

All of his thinking is governed by an `interesting axiom,' as Ernst Gabor Straus, Einstein's assistant from 1944 to 1947, once characterized it. For every fact, there exists an explanation as to why that fact is a fact; why it has to be a fact. This conviction amounts to the assertion that there is no brute contingency in this world, no givens that need not have been given. In other words, the world will never, not even once, speak to us in the way that an exasperated parent will speak to her fractious adolescent: `Why, I'll tell you why. Because I said so!' The world always has an explanation for itself, or as (Gödel) puts it, Die Welt ist vernünftig, the world is intelligible.

About Gödel's comments on natural selection, I find it hard to say anything remotely reasonable. Rebecca Goldstein cites an explanation about Gödel's intuitions about Darwinism by Steven Pinker, which essentially states that being a logician, Gödel disliked the non-determinism inherent in the Darwinian explanation. It comes across more as an apology than an explanation. But we do not need any explanation, of course. There is little doubt about Gödel's accomplishments, but like Einstein, the public, and even other scientists, expected these geniuses to provide deep insights (purely intuitive or a priori, by their very nature) on topics outside their expertise. The fault is not with them, but with us in taking everything they said all too seriously.

Update 5/29/2006: This update is meant to clarify one point that might be misunderstood. Unlike natural selection, Gödel's interests did in fact extend quite clearly into physics and even astrophysics. For a Festschrift in Einstein's honor, Gödel reluctantly published a paper that laid out a completely new model for the famous Einstein equations of General Relativity. In Gödel's interpretation so-called "Closed Timelike Curves" could exist, in which time can have cycles and you could revisit the past cyclically (perhaps this is also related to Gödel's interest in the existence of non-standard models in logic). For reasons not entirely clear to me, this interpretation has some link to observations of galaxies where if a significant number of them had a strong preference for spinning in one direction vs. another this would be a relevant finding. In a story that appears much later in Goldstein's book, some astrophysicists who were involved in such observations were asked to confer with Gödel and were taken aback at the sharp penetrating questions he had for them. `I wish we had talked to Gödel before doing our work.' was their comment after this conversation. It still does not explain to me his mysterious statement to John Bahcall above, but I suspect it does not mean what it appears to at first glance.