scepticism Flashcards
what is descartes’ evil demon?
this is global scepticism because we cannot resolve it by referring to external justification.
- if an evil demon is decieving me, then i cannot trust my calendar - i can’t even trust my visual perception.
- my friend may not even exist
what is an example of the evil demon?
i know 2+2=4
- no, the evil demon is messing with you
- 2+2 =5 and each time you add the two numbers together, the evil demon messes with your mind and makes you think the answer is 4
why is scepticism possible?
all of these scenarios are possible and there is no way you would be able to tell otherwise
- possibility of the evil demon cast doubt over everything we ordinarily consider to be knowledge
- we could be constantly making mistakes and there is no way of telling otherwise
what is descartes’ response to scepticism?
descartes’ previous argument prooves the existence of god
- having established this, descartes’ argues that god would not allow him to be globally deceived and so he can trust his perceptions and so he can trust that the external world exists
what is russell’s response to scepticism?
russell’s response to the sceptical challenge is that the existence of the external world is the best hypothesis
- and he adjusts the argument for the evil demon scenario
what is russell’s response ppcs?
p1) either:
p1a) the external world exists and causes my perceptions
p1b) an evil demon exists and causes my perceptions
p2) i can’t prove A and B definitively
p3) so i have to to treat A and B as hypothesis
p4) A is a better explanation of my experience than B
c) therefore, mind independent objects exist and cause my perceptions
what is a response to russell’s response to scepticism that the point was it couldn’t be proven?
russell’s claim that we cannot prove A or B definitively was the whole point
- descartes’ wasn’t trying to prove the evil demon exists, but saying that it was possible and so we cannot trust our ordinary knowledge
however Russell could respond that the possibility of the evil demon hypothesis does not mean knowledge is impossible. just because we can’t know for certain that we’re not being deceived by an evil demon, does not mean we can’t have knowledge
- certainty is not necessary - sure we might be being deceived but as long as we’re not being deceived and our beliefs are true the ordinary justifications are fine
what is the second response to Russell’s response that the external world is not the best hypothesis?
if we are being deceived by an evil demon or are in the matrix, etc… then our experience would appear exactly the same to us as if it was caused by the ecternal world
- thus we have no grounds to prefer one hypothesis over the other
what is locke’s response to scepticism?
locke gives two responses:
1) perception, unlike imagination, is involuntary - i cannot choose what i see or hear, which suggests that perception is caused by something external to my mind
2) my different perceptions are coherent (e..g sight and touch) - i can touch the fire with my hand to verify what i see with my eyes. this suggests there is a common reality that causes both perceptions
what is a response to locke’s response to scepticism?
1) we can respond that even if locke succeeds in proving that something external is causing his perceptions, he doesn’t succeed in proving that this perceptions is in any way an accurate representation of the external world - it could be the evil demon
2) just because our different senses are coherent, it doesn’t do much to prove they are representative of reality - an evil demon could be doing that and there is no way of telling otherwise
what is berkeley’s response to scepticism?
the evil demon doesn’t argue against idealism because idealism doesn’t make a distinction between perceptions and reality
- it doesn’t make sense to claim that the idea you are perceiving is somehow different from reality because ideas ARE reality.
- berkeley realises his perceptions are caused by something external to him and says it must be god because of the complexity of the perceptions.
what is the response to berkeley’s objection to scepticism?
his response assumes idealism is the correct theory of perception, but idealism faces its own problems such as hallucination
- if we accept that hallucinations are not REAL perceptions, the the sceptical problem reemerges: it is possible that all our perceptions are hallucinations
what is a reliabilist response to scepticism?
a reliabilist = knowledge is true belief formed via a reliable method.
- assuming i’m not being actually deceived by an evil demon, then my perception would count as a reliable method.
we cannot know whether we are in scenario 1 or 2 (another flashcard) but we don’t have to - if we are in scenario 1, then we can have knowledge of ordinary propositions because our perception would count as a reliable method.
- this means that we can’t know that we know such proposition, but we don’t have to. as long as we’re not in some weird sceptical scenario then knowledge is possible
what is an example of a reliabilist response to scepticism?
scenario 1: i am not a brain in a vat
- my perception is a reliable method because i am living in the real world and am perceiving it accurately
- my perception leads me to the belief i have hands
- my belief is true because this is scenario 1 and i am not a brain in a vat
- so i have a true belief formed via a reliable method that i have hands
- so according to reliabilism i know that i have hands
scenario 2: i am a brain in a vat
- my perception is not a reliable method because i am a brain in a vat being fed artificial stimuli
- my perception leads me to the belief i have hands
- my belief is false, because this is scenario 2 and i am actually a brain in a vat
- so i have a false belief formed via an unreliable method that i have hands
- so according to reliabilism, i do not know i have hands in scenario 2
what is a response to the reliabilist objection to scepticism?
the response assumes reliabilism is the correct definition of knowledge - but if we go with another definition of knowledge such as infallibilism then we can’t provide proper justification for ordinary knowledge because we can’t justify that we’re not in some sceptical scenario
