Lecture on the Modern Modal Ontological Argument

Introduction

• Discussion on how philosophers attempt to define God into existence using the ontological argument.
• Focus on the modern modal ontological argument by Alvin Plantinga, often defended by William Lane Craig.
• Original ontological argument by St. Anselm and René Descartes refuted by David Hume and Immanuel Kant.

Modern Modal Ontological Argument (Plantinga's Version)

1. Premise 1: A being has maximal excellence in a possible world W if it is omnipotent, omniscient, and wholly good in W.
2. Premise 2: A being has maximal greatness if it has maximal excellence in every possible world.
3. Premise 3: It is possible a being with maximal greatness exists.
4. Premise 4: Therefore, it is necessarily true that an omniscient, omnipotent, and perfectly good being exists.
5. Premise 5: Therefore, by Axiom S5, it is necessarily true that such a being exists.
6. Conclusion: An omniscient, omnipotent, and perfectly good being exists.

Criticisms of the Argument

• Criticisms inspired by Chris Hallquist, author of "The Uncredible Hallq."
• Argument is logically valid but doesn't prove anything substantial.

Issues with the Argument

• Axiom S5: Formal logic system where assumptions lead to absurd conclusions.
• Metaphysical Necessity: Claiming something is metaphysically necessary by possibility alone is problematic.
• Logical Equivalence: In S5, assuming X is necessary possibly exists is equivalent to X exists necessarily.

Absurdity of the Argument

• Example using Goldbach's Conjecture in mathematics to illustrate the absurdity of assuming unproven theories as true.
• Argument doesn't provide additional justification for belief in God beyond stating it's rational.

Comparison of Philosophers

• Alvin Plantinga: Admits the argument doesn’t prove the existence of God but suggests rational acceptance.
• William Lane Craig: Uses argument as proof of God in debates, contrasting with Plantinga's philosophical honesty.

The Great Demon Objection

• Example demonstrating why granting metaphysical necessity to an evil being is absurd.
• Objections to the Great Demon Objection:
  • Evil defined as absence of good is refuted by recognizing morally neutral actions.
  • Omniscient beings feeling convicted by moral law is refuted by the nature of a great demon.

Implications of the Great Demon

• If both a maximally good and evil being exist, they cancel each other out.
• Outcome: World would remain unchanged as neither could act.

Conclusion

• If the argument leads to at least two omniscient and omnipotent beings, it is flawed.
• Insisting only one being exists undermines the initial argument.
• The lecture aims to help critique the ontological argument's validity and offer entertaining rebuttals against it.