Plato Flashcards

For

“Knowledge is always is”

-Plato says that world is always changing, so truth is always changing.

-only way to attain true knowledge is in the unchanging; the forms

Meno argument

• we recognise imperfectly equal sticks as “nearly equal”

• must already have concept of equality to make that judgement

• pre-knowledge points to Forms existing independent of experience

Augustine argument

• Forms exists as “ideas in mind of God”

• theological grounding & shows lasting influence

R.M Hare

• moral language only makes sense if moral concepts like “goodness” are objective

• supports Form of Good existing independently

G.M.A Grube

• universal concepts like justice and beauty are meaningless without forms

• Forms explain how we communicate with abstractions

Mathematic argument (republic)

• Numbers and geometry behave like Forms

• perfect circle doesn’t exist in physical world, yet mathematicians reason about it w/ certainty

• If maths works, Forms work

Phaedo argument

• souls ability to recognize Forms before birth

• Forms exist independent of sense experience

• Don’t learn forms, we recollect it

Simile of Sun

• sun is to eye as Forms is to mind

• makes all knowledge possible and nothing would exist without it

• “Form of the good is cause of knowledge and truth

Iris Murdoch

"The Good has nothing to do with purpose... it is the magnetic centre"

• defended by Murdoch in 1970 shows it withstands modern scrutiny

Peter Geach

• abstract objects like numbers, propositions and moral values must have something non-physical to them

Against

Aristotle’s Third-Man Argument

• if horses resemble Form of the Horse, you need a third thing to explain what makes them both similar

• leading to infinite regress

Aristotle Seperation argument

form of horse that exists outside of actual horses is useless

Wittgenstein "Family Resembelance”

• things called by same name (e.g. games) do not have one shared perfect essence

• undermines whole basis for thinking a Form must exist to explain every concept

Aristotle “Doubling of the World” argument

• Plato made a whole new world of “Forms” to explain our current physical world

• World of Forms need just as much explaining

Russel

• ultimately rests on unverifiable assumptions

• no empirical foundation on existence of Forms

A.J Ayer (empricist)

• any claim about a non-physical realm is meaningless under verification principle

• can never be observed or tested