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Wagers and Evil

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Pascal’s Wager

Blaise Pascal (1623-1662)

Le silence éternel de ces espaces infinis m'effraie.

... from Pensées

(The eternal silence of these infinite spaces terrifies me.)

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Pascal’s Wager

● Prudential and Evidential Reasons for belief– Suppose I offer you ten bucks if you believe that there

is life on Mars (assuming you don’t already)– You don’t care one way or the other– It’s an easy ten dollars– You have a prudential reason to believe– But you have no evidential reason to believe (based on

my offer)– An evidential reason increases the probability of the

belief● example: you learn that Mars has methane in its

atmosphere and it’s hard to think of any source except living organisms

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Pascal’s Wager

● Blaise Pascal– philosopher of the 17th century– invented the theory of probability (with Fermat and the

Chevalier de Mere)● after being asked about a gambling problem● what are the chances – when rolling dice – of getting

10 and of getting 9?– invented decision theory

● What is the ‘expected utility’ of an action– multiply the chance of the action succeeding by the

‘payoff’ (utility) of the successful outcome– example: flipping coins, if you win $1.00 each time you

flip and win then what is the expected utility of a flip– $1.00 (payoff/utility) x 0.5 (chance) = $0.50 (Exp Ut.)

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Pascal’s Wager

● What is the expected utility of this game:– You get paid $1 if you roll a die and get 6– What is the expected utility of rolling?

● 1/6 x $1 = about 16 cents● What should you pay to play this game

● What about Lotto 649– Prize = $2M– Chance of winning = 1 in 14M– What is expected utility

● 2M / 14M = about 14 cents (very crude estimate)● What is the expected utility of this complex game:

– You flip a coin. You get paid $2n where n is the number of time you get heads in a row (game over with tails).

– EU = 2x.5 + 4x.25 + 8x.125 ...... = ?? infinity– what should you pay to play? (St. Petersburg paradox)

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Pascal’s Wager

● Pascal gave an argument which presents a prudential reason to believe in God.

● Here is the payoff matrix:

Plus infinity

A small negative

Minus infinity

A small positive

God exists

God does not exist

Believe in God Do not believe in God

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Pascal’s Wager

● To figure out the expected utility, you need the probability of God existing, P(G) = ε

● Suppose it is NOT zero, ε > 0● Thus the expected utility of belief is positive infinity!

Plus infinity x ε

A small negative x 1 - ε

Minus infinity x ε

A small positive x 1 - ε

God exists

God does not exist

Believe in God Do not believe in God

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Pascal’s Wager

● Problems– It is impossible to ‘decide to believe’ (Doxastic

voluntarism)● Try to believe, really believe, that there is an

elephant in the room right now.● Pascal’s reply: one can engage in actions that will

tend to make one believe (go to church, make religious friends, read the bible, etc.)

– The decision matrix is incomplete● What if there is a God who punishes believers

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Pascal’s Wager

● Suppose– Either God A or God B exists– God A imposes eternal punishment on those who

believe in God B– Same for God B (mutatis mutandis)

Plus infinity Minus infinityGod A exists

God B exists

Believe in God A Believe in God B

Minus infinity Plus infinity

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Pascal’s Wager

● Why take any argument like Pascal’s seriously?– The benefit is purely speculative– What is the special attraction of religion– Freud’s answer

● William James’s version of the wager– Pragmatism: truth = the useful– For most beliefs, evidence matters– For some, there is no evidential grip– Religious beliefs are of this kind– They provide a ‘vital benefit’– They are ‘low cost’ evidentially

William James (1842-1910)

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Pascal’s Wager

William Kingdon Clifford (1845-1879)

● Clifford’s reply– It is wrong to believe without evidence

If I steal money from any person, there may be no harm done from the mere transfer of possession; he may not feel the loss, or it may prevent him from using the money badly. But I cannot help doing this great wrong towards Man, that I make myself dishonest.

In like manner, if I let myself believe anything on insufficient evidence, there may be no great harm done by the mere belief; it may be true after all, or I may never have occasion to exhibit it in outward acts. But I cannot help doing this great wrong towards Man, that I make myself credulous.

The danger to society is not merely that it should believe wrong things, though that is great enough; but that it should become credulous, and lose the habit of testing things and inquiring into them; for then it must sink back into savagery.

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The Problem of Evil

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The Problem of Evil

● Here is an argument against the existence of God.– If God is omniscient, he knows if there is evil.– If God is omni-benevolent, he abhors evil.– If God is omnipotent he can eliminate what he abhors– God is omni-s/b/p– Therefore there is no evil if God exists.– But there is evil.– Therefore God does not exist.

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The Problem of Evil

● Possible replies– Since the argument is deductively valid, the only way

to attack it is to show that a premise is false.– So, perhaps the idea that God is omni-s/b/p is wrong

● What would such a new God be like?– Recall Greek pantheon– Manicheanism / Zoroasterianism

● Worship and the properties of God● What is the difference between this ‘weak’ God

and some ‘super alien’ being?● Suppose we were created by

technologically advanced aliens

– would you worship them?– would they count as God?

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The Problem of Evil

● Possible replies– The premise which asserts that if God exists then

there is no evil can also be attacked.● Soul Improving Evil

– Some bad things make us better people.● You have to let a baby fall for it to learn to walk

– God wants us to be as good as possible.– Therefore, soul improving evil is – on balance – good

worthwhile.● But ... are all evils soul improving?

– what about acne?● Why should God care?● 3-o/b/p cares about all

● Are there soul destroying evils?– Why are they permitted?

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The Problem of Evil

● Possible replies– The premise which asserts that if God exists then

there is no evil can also be attacked.● The Free Will Defense

– Maybe a world in which there are free beings is better than a world of ‘robots’

– If there are free beings, they can do evil – Many evils are explained this way– Two questions:

● Why can’t free beings freely always do good?– Possible worlds can be used to explain this

● Are all evils the result of freedom of will?

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The Problem of Evil

● The Problem of Natural Evil– Natural evils are evils that are not the result of the

free will of any agent– Earthquakes, famines (most often), diseases (most

often), hurricanes, tornadoes, floods, avalanches ...– Example: Lake Nyos

● Northwest Cameroon● 1986 CO

2 cloud

● about 1800 died● plus 3500 livestock

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The Problem of Evil

● More natural evil– parasitic wasps

● Darwin: ‘I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of Caterpillars’

– baby spiders eat their own mother● the babies literally suck their mothers dry. After several weeks the

mother becomes so weak she can hardly move. At this point the spiderlings attack their mother just as they would prey, injecting her with venom and digestive juices and consuming her entirely

– Human parasites

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The Problem of Evil

● Replies to the problem of natural evil:– One reply is to reduce natural evil to willed evil

● How is this possible?● Invoke the minions of Satan ...

– Another reply is simple● The ways of God are mysterious to a finite

intelligence that can observe only a tiny part of the universe

● Analogy: a very beautiful picture could have a very ugly part in it

– Note the difference between these two replies● The first accepts that natural evil is not necessary● The second has to say that all the natural evil we

observe makes the universe better than it otherwise would be

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The Problem of Evil

● Example:

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The Problem of Evil

● Example:

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The Problem of Evil

● Note the difference between these two replies● The first accepts that natural evil is not necessary

– This again raises the question of why God did not make the world in which Satan freely is good rather than evil

● The second has to say that all the natural evil we observe makes the universe better than it otherwise would be

– This is hard to believe