Knowledge Empiricism - Philosophy AQA (Unfinished)

Knowledge Empiricism

All synthetic knowledge is a posteriori while all a priori knowledge is merely analytic

Humes Fork

-> Only 2 types of knowledge;

1) Relations of ideas

- Analytic/Necessarily true/ A priori/ tautologies - > Known with certainty

2) Matters of fact

- Synthetic/A posteriori/ Contingent truth/ Known by experience/obvservation

Humes fork shows the only truths we know without experience are analytic truths and all synthetic truths must be/only known by expierence.

Descartes Sceptical Arguments

As synthetic knowledge is only gained through experience, it is uncertain

-- There is uncertainty of information gained through the senses as they have fooled him before

Descartes challenges it with scepticism

Descartes Three Waves of Doubt

1) First Wave of Doubt - Argument from illusions

Descartes doubts his senses because they have fooled him before -> Illusions

"Stick in water" - Deceived by his senses, therefore his senses should not be trusted

Descartes Second Wave of Doubt - Argument from dreaming

- Could be dreaming or awake, and there is no reliable way to tell whether I'm dreaming or awake.

Example: Piece of paper

When looking at a piece of paper;

I cannot know that I see a piece of paper because I cannot know that I am not dreaming of seeing a piece of paper.

As there is no way to tell when dreaming or awake, you cannot tell if you are not dreaming. Leads to uncertainty of the information the senses produces.

Descartes Third Wave of Doubt - Argument from the Evil Demon

Could be an evil demon deceiving us about everything

And there is no way to find out because;

If true, you wouldnt know because your whole expeirence is controlled by the demon

And therefore, you cannot know if this isnt true!

As there could be an evil demon deceiving/tricking us, this leads to scepticism/doubts the external world.