Monday, July 12, 2010

Zombie Ideas

There are smelly old ideas, wrong-headed notions, unnecessary assumptions, unwarranted premises, invalid axioms, that, if they could, should reek of decay and death. They are zombie ideas. Ideas that should be dead, but continue to exist, to be active, to thrive, to walk the earth like the living... like zombies.

They continue because they are coddled and swaddled inside the heads of stupid people. If you could smell the ideas, you'd never, ever let them enter your head, unless, of course, the inside your head was suffused with the rotting stench of death already, which I figure is what the insides of the heads of stupid people smell like. And not just any kind of stupid people, but Class IV Stupids: the ones that can process, retain, assemble, conclude, but then willfully ignore information. They got rotten brains. Rotten brains holding smelly old ideas.

Things like phlogiston, Flat Earth theory, geocentrism, the luminiferous aether, the caloric fluid, memes, and the rational market, to name just a few.

Libertarians love the rational market hypothesis. Libertarians are fucking idiots.

Take Milton Friedman and Jimmie Savage. They proposed that people, regular folks,  made economic choices according to rational decisions derived from complex statistical rules. When the obvious objection was made that this was just plain fucking ridiculous, because people are generally irrational goddamn animals, driven by greed and fear, who panic to buy and panic to sell, Friedman and Savage countered that billiard players do not calculate the mathematical physics equations behind their shots, but nonetheless act as if they did.  

In other words, when Friedman had to choose sides between empirical evidence and convenient theory, theory won out, and to hell with the facts.

Friedman's argument was: 

the relevant question to ask about the "assumptions" of a theory is not whether they   are descriptively "realistic", for they never are, but whether they are sufficiently good approximations for the purpose in hand. And this question can be answered only by seeing whether the theory works, which means whether it yields sufficiently accurate predictions.
 - The Methodology of Positive Economics 1953

Apparently, Friedman never studied the history of science. 

Take epicycles. The ancient astronomer Ptolemy, in trying to describe retrograde motion (the seeming temporary backward motion of planets in the sky) within the theoretical framework of a geocentric - an Earth-centered - universe, had to rely on the use of epicycles. 

In this model, planets did not directly orbit the Earth, but actually orbited in a small circle, called an epicycle, which travelled along a large circle, called the deferent, which orbited the Earth. This model of Earth at the center of the universe, with some planets traveling around in circles within circles stood for nearly 1500 years. The model (per Friedman above) used "sufficiently good approximations for the purpose in hand" and provided "sufficiently accurate predictions" of motion of planets in the sky. It was therefore, by Friedman's standards, a perfectly acceptable theory.

It was also completely full of shit. Try launching a rocket into space and navigating the solar system using epicycle navigation. You'll fly up your own asshole before you even get to the Moon.

Phlogiston (FLAH-jist-on) n: Obsolete term. A hypothetical substance once thought to be responsible for combustion. The material or elemental form of fire released as flame. Coined by physician/alchemist Georg Stahl (1660-1734). The Phlogiston theory was destroyed mainly by the great aristocrat and tax collector, Antoine Lavoisier, who almost single-handedly created modern chemistry. In recognition of this, French hippies cut his head off during the Terror.

In college, I read an excellent book, "The Art of Probability" by Richard W. Hamming. It is probably the best cautionary textbook for practitioners of statistics. Hamming used that phrase "art" for a very good reason. In all his years of examining the calculations and models of computer scientists and mathematical physicists, time and again he discovered that these models and calculations, being perfectly correct and consistent in math and logic, and producing extremely reasonable results - were based on incorrect assumptions, or were, even worse, simply modeling the wrong thing! 

And as such, there was a certain artistic component in the field of mathematical modeling and theory. Not so much an aesthetic component, as, for example, the way Einstein would speak of the beauty or elegance of equations. But rather more in a gustatory sense, as in a cook checking whether the ingredients were fresh, to avoid spoiling a recipe. 

If it smells like shit, don't eat it!

You'd have thought that the Crash of 2008 would have driven a stake through the heart of the idea of the rational market - and the notion of the productive class, for that matter - and that would be the end of it. But no, plenty of rotten brains out there, and plenty of shitty ideas.

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