Limits Of Knowledge Flashcards
Philosophical scepticism
According to the tripartite view of knowledge requires justification. Scepticism is the view that our usual justifications for claiming beliefs are inadequate, so we in fact do not have knowledge.
Brain-in-a-vat
My brain is connected to a supercomputer that feeds in the right impulses to generate illusions of reality as I experience now. My sensory experiences are produced by electrical signals. I’m living in a virtual reality. Since I think I am experiencing reality of physical objects and other people, I am being deceived. So, I cant know whether I am in fact a brain in a vat or not. But if I am then all my beliefs about what I experience are are false.
Normal incredulity
Happens when ordinary evidence makes us challenge a particular belief, grounded in ordinary evidence often alters behaviour.
Descartes 3 waves of doubt
Dreaming
Illusion
Evil demon
Illusion- 1st wave
Descartes argues that because his senses have deceived him before means that it is best not to trust them
Dreaming- 2nd wave
Descartes says if we can have dreams that are just like being awake, then how can he be sure that he is not dreaming now? Possibility means that any belief drawn from what he is perceiving around him may be false.
Evil demon- 3rd wave
Imagines the possibility of an extremely powerful demon employs his energies into deceiving him. If this is true then I wouldn’t know, because all my experiences would be exactly the same. So I cannot know whether I am being deceived or not.
Unless Descartes can rule out the possibility that he is being deceived by an evil demon, then he cant be certain of anything. He has reached the point of global scepticism.
Responses to Scepticism- Descartes
Descartes response to the global scepticism at the beginning of Meditation II is to use ration intuition and deduction. He begins with The Cognito argument. He argues that even if a demon is deceiving him, Descartes can know that he exists and that he thinks. He can know about his own mind and thoughts he has.
Descartes response- God is not a deceiver
Attempts to prove the existence of God, by his ontological argument, of using the concept of GOD. As an all-good and powerful God would neither create Descartes with such a deceptive nature nor allow him to believe with such conviction that what is actually false.
Criticism of Descartes God response-
the Cartesian circle
Descartes needs to prove that a non-deceiving God exists to show that his clear and distinct ideas must be true. But to establish God’s existence he has to put forward arguments using clear and distinct ideas. The approach is circular as it presupposes what it sets out to do.
Empiricist Responses
E.g. Locke, Russell, Berkeley
‘Can we know God exists?’ If ‘God exists’ is a synthetic claim, according to empiricism, we could only know that God exists from sense experience. Hume argued we can’t - reasoning involves claims that sense experience cannot establish. So, we can’t know whether God exists.
Reliabilism
Our true beliefs do not need to be justified to count as knowledge., the only need to be produced by a reliable cognitive process.
