Pascal's Wager

  • Pragmatic argument
    • Shows it is rational to believe in God despite a lack of evidence
      • Our best bet
    • Deductive
  • Blaise Pascal's definition of God
    • Assumed a Christian God
    • Being who is:
      • Infinite in nature
      • Promises an infinite reward to all who believe
  • Believing in God has a much higher "value" than not believing
    • (A) Believing and God exists --> infinite gain
    • (A) Believing and God does not exist --> finite loss
    • (B) Not believing and God exists --> eternal damnation
    • (B) Not believing and God does not exist --> finite gain
  • Expected utility
    • A --> $(+\infty)(0.5) - (finite)(0.50) = +\infty$
    • B --> $(-\infty)(0.5) - (finite)(0.50) = -\infty$
  • Expected utility of believing is infinitely better than not believing
  • Possibility of God existing can be as small as you want but cannot be 0
  • How/why you choose to believe doesn't matter, God doesn't care

The Argument

  1. Cannot demonstrate the truth of God's existence
  2. We must either believe or not
  3. If we have to choose between two options, and can't demonstrate which is correct, we should choose the option with the biggest payoff
  4. Expected payoff of believing in God outweighs the expected payoff of not believing
  5. Best option --> believe in God


  • No practical importance
    • Someone who doesn't believe can't just become a believer

Many-gods Objection

  • Did assuming a Christian God discount other conceptions of God?
  • Anyone believing in a different religion --> counted as a non-believer from perspective of Christianity
  • Have to take into account which god one believes in
    • Payoffs become unclear

Evidentialist Objection

  • Evidentialism
  • The idea that it is wrong to believe something without sufficient evidence
  • The main argument seems to set this objection aside

William James on Pascal's Wager

  • Tried to improve Pascal's Wager
  • Defended religious faith in The Will to Believe
  • Framework
    • Hypothesis
      • Something you might believe
      • A candidate for belief
      • Live --> something you could believe as the result of an inquiry
    • Option
      • Two more more competing hypotheses
      • Can be:
        • Live
          • Both hypotheses are live
        • Forced
          • If you have two chose one or the other of its hypotheses
        • Momentous
          • Great significance on the choice
          • The opportunity of the choice is fleeting
        • All options with the above features is genuine
  • Anti-evidentialism
    • When an option is genuine
      • Cannot settle with intellectual ability alone
      • One must decide using non-rational grounds
      • Four genuine cases
        • Moral
        • Personal relations (marriage, etc)
        • Social cooperation
        • Religious
  • Believes scientific options are not momentous
  • On religious belief
    • Best things are eternal
    • Better off now if we believe this is true

William James' Argument

  • Does not claim agnosticism or atheism is irrational
    • Simply concluding religious belief is rational
      • Defending the rationality of religious belief
  • Religious belief is a genuine option
    • Live, forced, and momentous
  • Whenever presented with a genuine option, two alternative intellectual strategies are available
    • Agnosticism
      • Risk losing out on possible truth (eternal happiness) in order to minimize risk of error
    • Belief
      • Risk error for a chance at a possible truth (eternal happiness)

Argument Philosophy Blaise Pascal