Pop-math author par excellence Keith Devlin drops Platonism .
In doing so, Keith edges a bit closer than I’d like to the social-contruction arguments of Reuben Hersh . I seriously doubt that “other cognitive creatures in another part of the universe might have different mathematics.” I don’t think, when we eventually get to the Lesser Magellanic Cloud, we shall find that two plus two equals five over there, or that the angles of plane triangles add up to 190 degrees. In any case, according to Martin Seligman (see below) there’ll be no-one there to discuss the matter with.
Still, the anti-Platonism is surely correct. The beginning of mathematics is abstraction — forming those stable mental structures we call “concepts” from repeated observations of the world around us. Abstraction, and math, then advance by forming hierarchies of concepts, the concepts at each level dealing with the concepts at the lower as if they were objects in the physical world. That is, as Keith points out, the only way we are equipped to treat them. The fact that we can only think about concepts as if they were objects, does not mean they are objects, though. Score one for Nietzsche. Still, anyone who seizes on this as an excuse to teach “feminist math” or “African math” should be tarred, feathered, and run out of town on a rail.
Devlin’s piece is one of many brief contributions to science webzine Edge.org ‘s Annual Question round robin: “What Have You Changed Your Mind About? Why?” addressed to notable intellectuals, with a bias towards the human sciences. For an exceptionally high quotient of interesting ideas to words, this is hard to beat. Try, according to your own interests:
- Philosopher-babe Rebecca Goldstein  giving Karl Popper a kick. Since Popper kicked Plato, this ought to cancel out Keith Devlin’s tossing the old guy overboard. In fact Goldstein is anti-Plato too, if you look closely. Plato had a bad year;
- Howard Gardner on Piaget ;
- Martin Seligman on intelligent life elsewhere in the universe  (Question: Isn’t it time we had a single word for the notion “elsewhere in the universe”? Like “abroad,” I mean? Suggestions welcome…);
- Michael Shermer on human nature ;
- Judith Rich Harris generalization . Judith is the Empress of child-development common sense;
- Richard Dawkins on flip-flops  (though in a recondite area of evolutionary biology, not in politics);
- Thomas Metzinger re-discovers Confucius  (Metz: “The world itself is silent.” The Sage: “Does Heaven speak?”)
- Mark Pagel on human group differences . Uh-oh. Get ready to be blacklisted by the Southern Poverty Law Center, Mark;
- Daniel Dennett on the homunculus  (that’s the little dude who squats there in your head, just behind the eyeballs somewhere, directing the action).
- Back-to-back John Allen Paulos and Leo Chalupa , seconding my observations (“walking north on the deck of a southboud ship”) about the stability of core individual personality.
What a feast of egg-head opinionating!
If there’s a common tendency running through many of these pieces, it is the fast-rising waters of naturalism, released by a half-century of discoveries in genetics, evolutionary biology, and neuroscience, submerging every other way of looking at the human world.
We are part of nature, a twig on the tree of life. If we are to have any understanding of ourselves, we must start from that. Final answers to ancient questions are beginning to come in. You may not be happy about the answers; but not being happy about them will be like not being happy aboutHeisenberg’s Uncertainty Principle . Sing it, Bobby:
Come gather ‘round people
Wherever you roam
And admit that the waters
Around you have grown
And accept it that soon
You’ll be drenched to the bone.
If your time to you
Is worth savin’
Then you better start swimmin’
Or you’ll sink like a stone
For the minds they are a-changin’ .