Descartes' Third Meditation Notes

Rene Descartes Third Meditation: Of God, That He Exists

Introduction

• Descartes' quest for truth:

  • First Meditation: Doubt of everything.

  • Second Meditation: Realization of existence as a thinking thing.

  • Third Meditation: Investigating God's existence using a rationalist approach.

Clear and Distinct Ideas

• Descartes categorizes ideas into three types:

  • Factitious ideas: Created solely in the mind (e.g., unicorns).

  • Adventitious ideas: Appear to come from external sources (e.g., sensation of heat).

  • Innate ideas: Not from external sources or created by the mind; present from the beginning and always true, independent of external factors and senses (truths minds are "stocked" with).

The Idea of God

• Clear and distinct idea of God:

  • An infinite substance.

  • Eternal, immutable, independent, omniscient, omnipotent.

  • Creator and producer of all things that exist.

Descartes' Argument for God's Existence

• Rationalist approach:

  • The idea of God is innate.

  • This innate idea must have been created by God.

  • Therefore, God exists.

• Descartes' Claim:

  • He, as a finite being, could not have created the idea of an infinite being.

  • Only an infinite being can create the idea of an infinite being.

  • The presence of the idea of an infinite, omnipotent God in Descartes' mind implies it was placed there by God.

• Cause and Effect:

  • The idea of God is the effect; God is the cause.

  • The idea originated from something powerful enough to create it: infinite, all-knowing, all-powerful.

Argument from Finiteness

• Knowing finiteness implies understanding infinity:

  • One can only know they are finite if they understand the idea of infinity.

  • Understanding finiteness requires understanding its polar opposite, infinity.

• Impossibility of approaching infinity by degrees:

  • Humans are finite and cannot gradually become infinite.

Hypothetical Scenario: God Does Not Exist

• Descartes considers the possibility that God does not exist to examine its reasonableness.

Descartes' Existence Without God

• Descartes defines himself as a thinking thing.

• If there was no God, how did he come to be?

Three Possibilities Considered

1. Self-Creation:

   • Rejected because if Descartes created himself, he would not have created himself with limitations; he'd have given himself all perfections and powers.

2. Another Non-Divine Source:

   • Rejected due to infinite regress.

   • What created the source, and what created that source, ad infinitum?

   • Without an infinite source (God), this continues endlessly.

3. Parents:

   • While parents are responsible for physical creation, this still leads to infinite regress (who created Descartes' parents, grandparents, etc.?).

Conclusion

• Having rejected all other possibilities, Descartes concludes:

  • An infinite being (God) must be responsible for creating life/thinking things.