Would the fact that the claim used to justify 'Knowledge is not possible' is unjustified, make 'Knowledge is not possible' unjustified?
Whilst researching philosophical skepticism, I found this answer to the question here which states the following:
[Jon Erison] Extreme skepticism is in fact self-defeating. According the the Wikipedia article linked in the question, philosophical skepticism is an approach that denies the possibility of knowledge. Therefore philosophical skepticism can not claim even that philosophical skepticism is correct. Therefore a critic of philosophical skepticism can not be compelled to accept any of its claims.
Would my reasoning below be correct, in assessing the validity of the claim Extreme skepticism is self-defeating?
Assuming the philosophical skeptic claimant makes the claim:
Knowledge is not possible
(and thus the claimant denies the possibility of knowledge).
The Claimant (a) believes in this statement; and (b) believes it is true. What is not certain at the moment, is whether the claim is justified, which would determine if the claimant knew the claim.
To illustrate why the claimant may not consider it justified there is an example provide by SEOP illustrating the non-consensual nature of belief:
for example, when Kai reads that astronomers no longer classify Pluto as a planet, he acquires a new belief (in this case, the belief that astronomers no longer classify Pluto as a planet).
Then If the claimant takes this further (Let P = that astronomers no longer classify Pluto as a planet) :
Kai believes that the author(s) of the book state P.
Kai believes that he has read that the author(s) of the book state P.
Kai believes that he has perceived that he has read that the author(s) of the book state P
Kai believes that he has perceived that he has perceived ...
And from hereon, it's just perceptions of perceptions all the way down.
(Just as a side note some definitions, such as that provided by , define perceive as:
to become aware of, know, or identify by means of the senses:
so just to clarify I'm only referring to aware of not know otherwise that would completely defeat the purpose of this question )
From this,(Assuming Kai stopped the process) Kai may either have faith ( faith, as in believing a perceived unjustified proposition) in a proposition or claim that:
Any belief is unjustified
(There's also the possibility that he doesn't claim anything afterward, in which case he wouldn't be deemed a skeptic?.)
So returning to the original claim, the claimant now justifies the claim
Knowledge is not possible
WITH
Any belief is unjustified