Scepticism - Philosophy

Cartesian Doubt

-Descartes aimed to find indubitable knowledge

-He wanted to throw out all ‘rotten apples’ and only be left with the ‘good apples’ (indubitable truths)

-3 waves of doubt.

Descarte’s 3 waves of doubt

1) We could be seeing things wrong (illusions/hypnotised/we are “mad”) OUR SENES ARE DECEIVING US (some times)

2) We could be dreaming (ALWAYS)

3) An evil demon could be controlling us (like a brain in a vat)

indubitable knowledge

true/certain knowledge

Local scepticism

Doubting a specific area of knowledge

Global scepticism

Doubting everything

Experiment for global scepticism

Brain in a vat, Descartes evil demon, the matrix

Descartes foundationalist approach to knowledge

We can know for certain:

1) Cogito ergo sum (i think, therefore i am.) (That i exist)

2) Clear and distinct ideas (are true)

3) God (exists)

4) Objects (exist)

Clear + Distinct Ideas general rule

Whatever i perceive clearly and distinctly is true.

Clear - able to think about an idea fully with all attention of our mind

Distinct - idea is clear and not defined in terms of anything else; it is something in and of itself

Descartes definition of God

A “supremely perfect being” - he argued this is the universal definition

Casual Adequacy Principle

If something occurs, what caused it to occur must have the necessary force/power to produce it.

Descarte’s trademark argument

1) The cause of anything must be atleast equal to its effect (CAP)

2) My ideas must be caused by something

3) I am imperfect being

4) I have an idea of God, a supremely perfect being

5) Therefore, I cannot be the cause of my idea of God

6) Only a perfect being can be the cause of my idea of God

7) Therefore, God must exist

Trademark argument part 2

This idea must come from God and is innate.

Descartes has banished the evil demon - God a supreme power.

We can trust clear and distinct ideas because God is not a deceiver.

Problems with trade mark:

His definition isn’t generalisable to all - other people have their own definitions.

What if some don’t have an idea of God?

Evil demon could create a false idea of God as supremely perfect being

The Wax Example

Therefore, whatever wax is, as a substance, I know in my mind alone, not from my perceptions of the object.

When you look at wax you always something different - its qualities do not remain the same. It changes into all sorts of forms.

The external world

Properties are subject to deception but substance is not. Argued for a form of indirect realism.

Hume on Self

“A thought, implied one thought”

We do not experience a continous self but rather a series of conscious thoughts one after another, constantly changing.

We never experience a single mind. We notice similarity and therefore infer that there is a single mind thinking this series of thoughts.

Hume on substance

Hume argued just like the mind, we never perceive one continous object. Instead, we perceive one object, then another, then another etc - each time looking in a similar direction. Continual substance.

C+D ideas evaluation

Circular logic. C+D ideas are only true/certain if God exists but for God to exist, we must know that C+D ideas are certain. Cartesian circle.

Challenging the Casual Adequacy Principle

Small cap = big avalanche

Match = Big fire

Less power in cause than in the affect.

Descartes response: we need to consider TOTAL cause

Hume on causation

Cause and effect we know it from experience. Since we have never experience the cause of our idea of God, we cannot say it is God himself.

Idea of God is not innate.

Hume’s attack on God as “supremely perfect”

God is a complex idea made up of qualities that we have just adapted from experiences of human. God is just a being with all the attritubtes of a human but “extending beyond all limits”

Rationalism

knowledge can be obtained through rational thinking and reason

a priori

Empiricism

Knowledge comes from experience via the senses.

a posteriori

Reliabilism

Rather defining knwlowdge as needing to be ‘justifiable’, it must be ‘reliable’ - based on some cognitive processes. What they might say is: I do know that physical objects exist, i just don’t know if i know it. Flexible wat if defining knowledge