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Jayson_Virissimo comments on Making Beliefs Pay Rent (in Anticipated Experiences) - Less Wrong

110 Post author: Eliezer_Yudkowsky 28 July 2007 10:59PM

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Comment author: Jayson_Virissimo 06 February 2012 08:56:28AM *  0 points [-]

Know falseness is not really same thing as falsifiability. Known falseness is useless in deciding whether a theory is scientific. Both the Greek pantheon and geocentric theories are known to be false.

Falsifiability is simply the requirement that a scientific theory to list things that can't happen under that theory. Falsifiability says scientific theory don't look for evidence in support, they look for evidence to test the theory.

The fact that no false statements appear doesn't mean that the scientific theory isn't falsifiable. The fact that every statement of a theory has been true does not mean that the theory is falsifiable.

Nothing in this reply contradicts anything I have asserted. I was merely claiming that if falsifiability is a sufficient condition for a hypothesis to be "scientific", then all theories known to be false are scientific (because if we know they are false, then they must be falsifiable). I'm not being contrarian; I'm pointing out a deductive consequence of the very definition of falsifiability that you linked to. Hopefully this closes the inferential distance:

  • If a hypothesis is falsifiable, then it is scientific.
  • If a hypothesis is known to be false, then it is falsifiable.
  • Therefore, if a hypothesis is known to be false then it is scientific.

I am merely denying the first premise via reductio ad absurdum, because the conclusion is obviously false (and the second premise isn't). If you took my claim to be something other than this, then you have simply misread me.

Comment author: TimS 06 February 2012 02:59:51PM 1 point [-]

That's much clearer. I didn't intend to assert that falsifiability was a sufficient condition for a theory being scientific, only that it is a necessary condition. That's what I mean by saying it was a partial definition.

Thus, I don't intend to assert the first sentence of your syllogism. Instead, I would say, "If a hypothesis is not falsifiable, then it is not scientific." Adding the second statement yields: "If a hypothesis is know to be false, then it might be scientific." That's a true statement, but I don't claim it is very insightful.