Introduction

---

Anselm's Ontological Argument

• Definition: God = that than which nothing greater than can be conceived.
• We will treat the argument as a reductio ad absurdum
  • The fools premise: God does not exist.
  • Conclusion: we can conceive of something greater than God (for example, something which has all the properties of God but also exists).
• Substituting the definition into the conclusion we get: we can conceive of soemthing greater than that than which nothing greater than can be conceived.
• This conclusion is contradictory, so if the argument is valid, we must reject a premise; namely, we must reject The Fool's Premise.
• Hence, God exists.

Paley's Design Argument

• The world is complex and has functional roles that support each other.
• The best explanation of this complexity of functional roles is that the world is designed.

(A popular revision fo the Design Argument:) The Anthropomorphic Argument

• There is life
• The physical constants of our universe are suitable for life.
• If the physical constants of our universe were very slightly different, there would have been no life.
• Corollary: the conditions for life are very unlikely.
• Conclusion: the best (most probable) explanation for the favorable conditions of our universe is that the universe was designed to be favorable to life.

Pascal's Wager

• Either God exists or God does not exist.
• You can believe that God exists or believe that God does not exist.
• There are four situations to consider:
  1. If you believe that God exists, then if God exists, you will get an infinite reward.
  2. If you believe that God exists, and God does not exist, you will suffer a small cost.
  3. If you believe God does not exist, and God does not exist, you gain some small amount.
  4. If you believe God does not exist, and God does exist, you suffer vast or infinite loss.
• It is best to believe that God exists.

What have we learned?

Philosophers have not identified a deductive argument for the existence of God that is valid.
• The traditional arguments, were they valid, would establish the existence of a "philosopher's god" and not a personal God.
• Most philosophers have concluded that belief in a personal God must be based on either
  • Direct evidence (e.g., observation through a religious experience); or
  • Faith