[extropy-chat] Bayes, crackpots and psi

[Robin Hanson]

On 12/20/2004, Hal Finney wrote:
>The analysis Damien posted of disagreement about psi on the basis
>of Bayesian reasoning is OK as far as it goes, but it stops with the
>assumption that people have different priors.  Where did those priors
>come from?  Robin Hanson argues that we shouldn't assume people are born
>with different priors: we are all descendents of a common ancestor and in
>that sense we all have the same priors, with our different paths through
>time and evolution being mere information added to that original set of
>prior beliefs.

Well that is one of the arguments we offer in http://hanson.gmu.edu/deceive.pdf
but I think a stronger argument is in http://hanson.gmu.edu/prior.pdf

>... One side or the other finally has to say, you're being irrational ...

And given how common irrationality is, of course this has to be a pretty
plausible hypothesis.  Unfortunately, irrational people also usually do not
admit that they are irrational, and instead think that those they disagree
with are irrational.  So the question is if really have any reasonable way
to tell if it is you or they who is more irrational on this issue.

>Another possibility is that they don't really disagree as much as
>they seem to.

Yes, sometimes people think they disagree when they really do not.  But
usually deeper probing finds real disagreements, so this can't be the
explanation for most disagreement.



Robin Hanson  rhanson at gmu.edu  http://hanson.gmu.edu
Assistant Professor of Economics, George Mason University
MSN 1D3, Carow Hall, Fairfax VA 22030-4444
703-993-2326  FAX: 703-993-2323