Epistemology - Scepticism (copy)

scepticism is (3)

scepticism is (3)

the belief that our usual justification for claiming that our beliefs amount to knowledge are insufficient, so we do not in fact have knowledge

what thought experiment leads to scepticism

brain in a vat

why can we not know we are not a brain in a vat

our experiences would be exactly the same

even if we aren’t a brain in a vat, what’s the issue with our beliefs about the world (leading to scepticism)

our beliefs aren’t justified

scepticism about a specific claim our area of knowledge

local scepticism

scepticism about all knowledge claims especially the world outside the mind

global scepticism

Descartes’ waves of doubt

illusion, dreaming, evil demon

Descartes’ responses to evil demon

proved existence of God, God is not a deceiver

Descartes response to dreaming

we can distinguish between dreams and reality, God would not deceive me

Descartes response to illusions

our individual perceptions can deceive us

we have good reason to believe the real world exists, so we shouldn’t be sceptical of it (trust our sensation and reflection, best hypothesis) but we can apply local scepticism to things)

John Locke’s response

no reason to believe sceptical arguments (brute fact) if 100 people agree there is a table there is probably a table, physical objects cause our sense-data and correspond to them in a significant way

Bertrand Russel’s response

in experiencing ideas, we are experiencing reality, we cannot be mistaken about our ideas as its a direct idea, can’t be a supercomputer as that’s a physical object, uses God instead

Berkely’s response

if my beliefs are caused by a reliable process, and are true, then I have knowledge. Supposing I am not a brain in a vat then perception is a reliable process, I don’t need further justification

reliabilism response