Le 04-janv.-06, à 19:30, Brent Meeker a écrit :
> Bruno Marchal wrote:
>> Hi John,
>> I think you may have problems because you are not used neither
>> trained in axiomatic thinking. The idea consists in NOT defining the
>> objects we want to talk about, and keeping just some needed
>> properties from which we prove other theorem.
>> Let me give an example with the idea of knowledge. Many philosophers
>> agree that knowledge should verify the following law, and I take it
>> as the best definition of knowledge we can have:
>> 1) If I know some proposition then that proposition is true
>> 2) If I know some proposition then I know that I know that proposition
>> 3) If I know that some proposition a entails some proposition b, then
>> if I know a, I will know b.
>
> But that doesn't capture meaning of "know".
But nobody knows or agree on the *meaning* of "know", that's was my
point. If *you* think it leaves something out, for a mathematician it
means that you agree with the definition!
And then you propose a stronger theory by adding 4:
> It leaves out 4) If I know some proposition then I have experience
> causally connected to the fact that makes it true. See c.f. Gettier's
> paradox.
Now, that "4" *is* problematical because it refers to a undefined
notion of causality, which itself can only be defined axiomatically.
Bruno
http://iridia.ulb.ac.be/~marchal/
Received on Thu Jan 05 2006 - 08:55:03 PST