the ontological argument of descartes

key facts:

• rene descartes (french)

• 1596-1650

• mathematician

• philosopher

• his version of the OA appears in his work ‘Meditations’ (1641)

Perceiving: the use of the senses in order to gain understanding

thinking: the use of the mind in order to gain understanding

“Because I am thinking, I must exist, at least in some kind of mental sense, or ‘cogito ergo sum’ (I think therefore I am).”

immutable nature:

“God exists” > descartes wants to prove this is also a tautology | “triangle has 3 sides” > “tautology objectively true by definition”

> “a triangle has three sides”

subject

predicate

>”God exists” (existence)

• God is defined as supremely perfect. perfection must be a predicate of existence. therefore, if God is perfect, then he exists

  exist contains perfection = predicate

summary:

• ‘God is a supremely perfect being’

• ‘existence’ is a perfection

• to think of God without existence is like thinking of a triangle without its three sides

• it is therefore illogical to think of the concept of God without the concept of existence

these are all examples of reduction as absurdum arguments; they begin with a proposition and attempt to prove (through logical reasoning) that it would be absurd to reject the proposition