Epistemology - Intuition and Deduction Flashcards
What is intuition?
The ability to know something is true just by thinking about it
E.g. Descartes’ cogito
What is deduction?
Deriving true propositions from other true propositions (using reason)
E.g. if a is true then b is true, a is true, therefore b is true
What knowledge do empiricists claim can’t be acquired through intuition and deduction?
Knowledge of synthetic truths
What are Descartes’ 3 waves of doubt?
- Illusion
- Dreaming
- Deception (evil demon)
What is the cogito?
Descartes claims that he can know for certain that he exists as a thinking thing, through the intuitive argument:
“I doubt, therefore I think, therefore I am.”
What is a clear and distinct idea?
Self-evident claims that are indubitable to an attentive mind (impossible for the proposition to be false)
What comprises Descartes’ intuition and deduction thesis?
Intuition: having clear and distinct ideas
Deduction: using clear and distinct ideas (they can’t be false since clear and distinct ideas are indubitable)
What is Hume’s objection to Descartes’ cogito?
Existence, for Hume, is not a relation of ideas; mental substance is incoherent as there is not one consistent and continuous thinker (therefore existence cannot be a clear and distinct idea)
What is Berkeley’s objection to Descartes’ cogito?
He agrees that mental substance exists, but he disagrees with the rationalist approach as we experience our own minds as opposed to deducing we exist via a priori reasoning (Berkeley is an empiricist, therefore existence is not a clear and distinct idea for him)
What is Descartes proof of the external world?
- My perceptions are involuntary so they cannot be caused by my mind
- Therefore the cause of my perceptions must be external to my mind
- God exists but does not cause our perceptions; he gave humans the belief that the external world exists, and God is not a deceiver so the external world must exist
Outline Descartes’ trademark argument
I have the concept of god and my concept of god is that he is infinite and perfect
Yet i am finite and imperfect
And the cause of an effect must have as much reality as the effect
Therefore god must’ve caused the idea and imrpinted it on our minds
Outline Descartes’ cosmological argument
If i caused my own existence i would give myself all perfections
However i don’t have all perfections
So i am not the cause of my own existence, and whatever caused me to exist must either have caused its own existence or been caused by something else
There can’t be an infinite chain of causes so something must’ve caused its own existence (god)
Outline descartes’ ontological argument
I have the idea of god in my mind, and the idea of god is a supremely perfect being
A supremely perfect being doesn’t lack any perfection
Existence is a perfection
Therefore god must exist by definition
