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eternal_neophyte comments on Crazy Ideas Thread - Less Wrong Discussion

22 Post author: Gunnar_Zarncke 07 July 2015 09:40PM

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Comment author: eternal_neophyte 08 July 2015 09:49:39PM 3 points [-]

Thesis: All knowledge is synthetic. There is no such thing as an "obvious" truth, and both mathematics and logic are empirical sciences. Every "axiom" is open to question and the axiomatization of arithmetic was nothing more than an attempt to find a "spanning set" of mathematical statements which are logically independent. Which is to say the logicist programme was flawed in ways much more fundamental than just being limited by incompleteness; it was doomed as soon as Frege mocked Mill.

Problem: Logic is a means of specifying the object under consideration (assuming everyone knows what I'm talking about since this is discussed in one of the sequence articles). Throwing out an axiom, say by defining a non-commutative form of addition, is changing the subject. We cannot make any assertion about arithmetic (and hence cannot make any discoveries about arithmetic) without first logically circumscribing the subject. Perceiving a given quantity of object in the visual field relies on a contingent definition of the unit. Synthetic knowledge of arithmetic seems impossible.

Proposed resolution: Weaken definition of knowledge from "justified true belief" simply to "true belief". Some might want to haggle over what "justification" is and object that we shouldn't throw out the whole concept because both logicism and empiricism seem to fail to provide it infallibly. Mathematical knowledge is then attained only insofar as we guess correctly with respect to the independence of our axioms.

Interested in hearing what would be regarded as "standard" objections to the above (which is not to say I'm disinterested in original objections; just believe in respecting others who have worked on a problem by learning what they've done).

Comment author: IlyaShpitser 09 July 2015 08:46:56PM 2 points [-]

If you throw out justified you then consider what we intuitively consider delusional beliefs who happen to be accidentally true to be knowledge. Which conflicts with intuition. You can always bite the bullet on any conflict but that's boring.

Comment author: eternal_neophyte 09 July 2015 09:00:06PM *  0 points [-]

It depends on what you call "delusional". Just to be clear: I'm not arguing that justification is impossible, but that "at bottom" all our beliefs rest on uncertain axioms that are provisionally treated as certain, but which aren't justified. Aesthetic considerations such as boring vs. interesting, elegant vs. obtuse, natural vs. tortured then loom much larger in the actual part they play in determining beliefs than supposed certainty about axioms.

Additionally there's a problem with whether it's actually possible to truly believe something without justification. If your beliefs don't make contact with your experiences then what exactly is it you're believing in?