Monday, April 13, 2009

Correct reasoning

So much of what I write here is really about correct reasoning with baseball as the example. This is because I love baseball and also want to reason about it (and everything else) correctly. Thus, this post, while not explicitly baseball related, naturally piqued my interest. Indeed, I saw it because it was linked by J.C. Bradbury over at Sabernomics, a baseball economics blog. The whole thing is well worth reading, but I will excerpt just a small amount.
If we don’t sometimes defer to the expert consensus, we’ll systematically tend to go wrong in the face of one-way-hash arguments, at least our own necessarily limited domains of knowledge.  Indeed, in such cases, trying to evaluate the arguments on their merits will tend to lead to an erroneous conclusion more often than simply trying to gauge the credibility of the various disputants. The problem, of course, is gauging your own competence level well enough to know when to assess arguments and when to assess arguers. Thanks to the perverse phenomenon psychologists have dubbed the Dunning-Kruger effect,  those who are least competent tend to have the most wildly inflated estimates of their own knowledge and competence. They don’t know enough to know that they don’t know, as it were.
Yes! Correct reasoning is hard. As much as I love it, I do it wrong all the time. Indeed, this blog serves to enshrine all the times I have reasoned incorrectly. I keep meaning to do a post summarizing all the analyses I've f***ed up, but I keep not doing it (insert Freudian crap about ego and id and all that jazz).

In any case, since we really don't have the time to reason correctly about every last thing, we absolutely must adopt the position that other people likely know more about any given issue and that we should generally defer to their judgement. Yes, this creates the problem of identifying who the experts are, but this is probably a more tractable problem.

The more I learn about computer programming or guitar or economics or baseball, the more I understand how little I truly know about any of them. This is why it is so important not to commit to a particular position just because you feel like you need to choose a side. You should never commit to a position until you have to, and even then you should commit to it only for as long as is necessary, at which time you should "uncommit" and continue to examine all evidence for every position. This is not easy to do.*

Finally, from the same post:
Addendum II: In the comments Pithlord lives up to his moniker:

Most fallacies aren’t really fallacies when you reinterpret them as Bayesian reasons to give an idea more credence rather than iron-clad syllogisms. Without the “argument from authority” and the “ad hominem fallacy”, you would either never get lunch or you’d give all your money to Nigerian spammers.
Bingo. Probabilistic reasoning is insanely hard. In propositional logic, it is a grave fallacy to say "A implies B; B is true; therefore A is also true." However, probabilistically, when you say that "if A is true, B is more likely to be true; B is likely to be true; therefore A is more likely to be true," you are 100% right. That's messed up.

* Please note that I am not saying that no position is ever right or wrong. Rather, I am saying that knowing which position is right and which is wrong can only occur with increasing degrees of certainty. Nor am I arguing that one should never advocate for a position or argue a particular viewpoint. Indeed, if we did not do this, we would never be able to communicate positions or viewpoints to people that need to hear them. Rather what I am saying is that the appropriate attitude when advancing a position is to remember that you could be wrong and to try to learn how you could be wrong from the opposing position.

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