Descartes

(1596-1650)

Dualism

“two realm view” invented by Plato. what exists is either physical or mental; some things have both a physical and mental component

Materialism

physicalism, only the physical exists

Idealism

only the mental (spiritual) exists, physical things are manifestations of thought or mind

Double Aspect Theory

mental and physical are different ways of looking at the same thing

Descartes Doubting Methodology

Dream Conjecture “for all I know, I might be dreaming”

Evil Demon Conjecture - some malevolent demon is deceiving me so what I regard is true is actually false

Cognito Ergo Sum

“I think, therefore I am”

can doubt anything save for this one truth because to doubt is to think and exist

Clear and Distinct Criterion

the certainty of his existence was an essential characteristic of certain truth and anything that was as clear and distinct as his existence was also certain

“Whatever I perceive clearly and distinctly is certain”

Extension and Thought

E: material substance (occupancy of space)

T: mind

substance requires nothing other than itself to exist

Descartes Dualistic Metaphysics

1. Material things, including the body, are subject to physical laws

2. The immaterial mind can move one’s body

Parallelism

the mind doesn’t cause the body to move; there are two parallel events. a mental and material happening. the act of willing and movement coincide and make an appearance of the willing causing the moving

Occasionalism

variant of parallelism, when I will my hand to move, it is an occasion on which God causes my hand to move.

Epistemological detour

“What do I know is the basic stuff?” and “Of what can I be certain about the nature of reality?” What can be known?

Descartes’ Proof of God

1. He had an idea of God and there must be a cause for his idea - God. God is invoked as the cause of the idea of God

2. I exist as a thing with an idea of God, everything that exists has a cause, the only thing adequate to cause and sustain me is God, therefore God exists. God is invoked as the cause of Descartes’ idea of God

3. My conception of God is the conception of a being that possesses all perfections, existence is a perfection, therefore I cannot conceive God as not existing, therefore God exists.