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johnwcowan comments on Belief in Belief - Less Wrong

66 Post author: Eliezer_Yudkowsky 29 July 2007 05:49PM

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Comment author: johnwcowan 26 July 2011 11:28:57PM 1 point [-]

Knowledge involves more than belief. You know p if all of the following are true:

1) You believe p. 2) p is true. 3) If p were not true, you wouldn't believe it (justified true belief) 4) If p were true, you would believe it (Gettier belief)

And most beliefs, such as the belief that my keys are in my left pocket, are trivial and true, as well as being based on data.

Comment author: TheOtherDave 27 July 2011 01:57:01PM 1 point [-]

At least in my mind, the processes that generate beliefs like "my keys are in my left pocket" are not perfectly reliable -- at least once, I have thought my keys were in my left pocket when in fact I left them on the dresser.

So #3 is demonstrably false for me; on this account, I don't know where my keys are.

Which is perfectly internally consistent, though it doesn't match up with the colloquial usage of "to know," which seems to indicate that the speaker's confidence in p is above some threshold.

There's nothing wrong with having precisely defined terms of art, in epistemology or any other field. But it can lead to confusion when colloquial words are repurposed in this way.

Comment author: MixedNuts 27 July 2011 02:30:10PM 2 points [-]

Add "with high probability" everywhere.