“Platonicity” is a word coined by Nassim Nicholas Taleb in his second book,
The Black Swan. It means the human tendency to find patterns. Putting it that way sounds good, but Taleb is critical of Platonicity. He contrasts Platonists with practitioners. He exposes the “ludic” fallacy, where one builds a mathematical model of something (as in Latin “ludens,” playing a game) but then believes the model–the rules of the game–too much. It’s another form of the fallacy of induction: All swans that I’ve seen are white, therefore all swans are white.
Some people undergeneralize. I always overgeneralize, so I needed Taleb’s book.
Hmm, that was probably an overgeneralization. I usually overgeneralize.
Taleb has been a practitioner–an options trader in the stock market–, and is now a college professor. So it is possible to profess mathematics as well as to practice it! Qua option trader, he gives the following advice for investing in stocks: 95% conservative and 5% on highly improbable “black swans.”
I used to call black swans “albino crows” when I discussed the fallacy of induction in my classes. (See, I did know what Taleb is saying, theoretically at least.) But Taleb is such a good historian that he knows that black swans were John Stuart Mill’s example as early as the 19th C. From now on, all albino crows are black swans. (Take that, W. V. O. Quine!)
Besides J. S. Mill, Taleb’s heros include Umberto Eco, Benoît Mandelbrot, David Hume, and Karl Popper. I’ll agree except for Hume, since I do believe in miracles, and I do believe in moral truths.
Taleb’s anti-heros are almost all economists who have won Nobel prizes, like Kenneth Arrow, Paul Samuelson, Robert C. Merton, and Myron Scholes. He spares laureate Herbert Simon, who extended George Zipf’s linguistic work on power laws to a broad array of phenomena. (This link in turn links to Simon’s 1955 article.) Taleb is very big on power laws.
Published in 2007, Taleb’s book cautions that Fanny Mae is so exposed to risk that it is “sitting on a barrel of dynamite, vulnerable to the slightest hiccup.” (225 n.) For a moment I thought that this proved that Taleb’s book is sound: Fanny Mae is in trouble as I write! It proves no such thing. There I was falling for the inductive fallacy again.
Now that I’ve read the book, I see examples of it everywhere I look. You’d expect that of an overgeneralizer, wouldn’t you?
Theology. Between the premodern period and the current postmodern period, the Western world had a run of Protestant Platonicity in developing systematic theology instead of Biblical (narrative) theology. Gibbs and Bolger in their 2005 book
Emerging Churches: Creating Christian Community in Postmodern Cultures
claim that this was spurred on by the printing press. They claim that worship for Protestants (my people!) became word-centered, linear, structured. I am reading this book now.
Beware: Posmodernism plays loose with the idea of truth. I’ll blog about truth separately, but for now just two hints. First, in the Christian worldview, Truth is a Person, not a proposition. Second, in logic besides the inductive fallacy mentioned above, there is also a deductive fallacy, wherein the reasoning is airtight but the premises are false. See my friend Scott Moonen’s
blog on a proof for the non-existence of God for a nice illustration of this.
Math. Besides championing the power law mentioned above, thanks to Taleb I’m more likely to be critical of assuming a normal distribution, or even a lognormal distribution. Or even further a Bayesian approach. I’m happy to say that my most recent professional publication tempers arguments about lognormal distributions and Bayesian reasoning with common sense.
Physics. Lee Smolin’s latest book,
The Trouble with Physics: The Rise of String Theory, the Fall of a Science, and what Comes Next, is critical of the current state of Physics too enamored with Platonicity. I read that just before I read Taleb.
(h/t Both Taleb and Smolin were recommended to me by my good friend and polymath Curt Byers. Thanks!)
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