Monday, November 30, 2015

Are the beliefs of Mormons less likely than those of Christians? - On the debate between Sam Harris and Cenk Uygur

The debate between Cenk Uygur and Sam Harris about differences between different religions has been highlighted again.

In short, Sam Harris’ point is that Mormonism is based on less likely beliefs than Christianity, because Mormons believe that Jesus will come back to Missouri where as Christians believe that he will come back somewhere, without specifying the exact place for that event to happen.

Cenk Uygurs point is, that both religous beliefs are false (like 2+2=5) and therefore adding the specificity of believing Jesus will return in Jackson County Missouri does not decrease the likelihood.

You can watch the exchange here at 17:54 min (external link)

So, who is right?

Let’s look at another example that is similar to this debate, studied by Daniel Kahneman and Amos Tversky:

Linda is 31 years old, single, outspoken and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti-nuclear demonstrations.* 
Linda is a bank teller. (T)

Linda is a bank teller and is active in the feminist movement. (T&F)

Although the first statement (T) is more likely, 85% of the participants in their study believed the second statement (T&F) was more likely, probably because (T&F) is more representative of a person like Linda.

However, (T) Linda is a bank teller, includes (T&F) because the later statement includes all possible extracurricular activities; also that of her being a feminist.

If (T&F) is true, (T) also has to be true, therefore P(T&F) ≤ P(T). The conjunction of (T) and (F) (T&F) can’t be more likely than each part, (T) and (F) on its own. 

Not recognizing that P(T&F) can’t be greater than P(T) is called conjunction fallacy.

Does this mean, Sam Harris is right and Christianity is a little less absurd than Mormonism?

If we look at the Linda-Example, not if for some reason bank tellers would not exist anymore. Maybe the financial world finally crashed and all former bank tellers are now tale-tellers. In this case, the probability of Linda being a feminist would not change the probability of her being a bank teller, because we know that bank tellers don’t exist, P(T&F) = P(T) = 0.

This is the argument made by Cenk Uygur. He says, Jesus doesn’t exist, therefore it does not matter where he is expected to return to earth to free us all from our sins, it’s not going to happen, the probability is 0 point nothing. Therefore P(Jesus)=P(Jesus&Missouri)=0. That would be true for any other location as well, whether it is Jerusalem, Missouri or the White House.**

So is Cenk Uygur right? If the probability of Jesus existing/returning is 0, yes. If it is anything greater than 0, then no, the probability of Jesus existing P(Jesus) would be greater than the probability of Jesus existing and coming back in Missouri P(Jesus&Missouri). Unless of course Jesuses always return to Missouri, or the probability of Jesus coming down in Missouri would be 100%.

In the Linda example, that means, if we would know Linda is a feminist for sure (100%), her being a feminist would not decrease the probability of the second statement over the first (they had the same likelihood in this case, P(T&F)=P(T)). Likewise, if we would know that all bank tellers are always feminists the probability of the second statement over the first would not be decreased P(T&F)=P(T).

For a more realistic example: P(being dead)=P(being dead & no neuronal activity) because the lack of neuronal activity is included in being dead***. Unless one is Jesus himself, I believe Jesuses have not been studied extensively.

But since Sam Harris and Cenk Uygur agree that Jesuses don’t always return in Missouri nor Missouri is in any way the certain location, the question boils down to the question if the probability of Jesus returning (existing) is greater than 0.

If it is 0, the probability for him returning in Missouri is as high as anywhere else, namely 0.
But Christians and Mormons both don’t believe that the probability of Jesus existing and returning is 0. So maybe which religion is more absurd should be judged on their own (shared) premise (that Jesus existed and will return)? If this premise is accepted, the more (independent, uncertain) details are added, the lower the probability of the story happening exactly as outlined is.

On the other hand it might be that it is just these details that make the story believable for some – however absurd they are for other people: Good stories require details and lively characters.

Therefore I don’t think that the real oversight of a lot of believers is the commitment of the conjunction fallacy, but rather the unquestioned acceptance of religious stories as historical fact from which directions, predictions and values can be derived, despite counter evidence – a point they also briefly discuss here.

Or in other words: Religions are not absurd because their believers may commit the conjunction fallacy, but because they uncritically accept the absurd underlying story which leads many of them to commit logical fallacies.

English is not my native language. I’m sorry for the not very straight forward expression of my thoughts and will of course correct my text if mistakes are pointed out to me. Thank you!

* Please consider that Kahneman & Tversky used this example in the 70th and early 80th.

** After writing this, I saw a video in which Cenk Uygur portrays Sam Harris as if he had said Jesus were more likely to return to Jersualem than to Missouri. This is, however, not the case, as you can see in the first video clip (or hear on Sam Harris' podcast at minute 53:20). Therefore I concentrate on the question whether one specific location is inevitable less likely than any location, as I believe this was the real point of discussion.

*** If measurement errors would not exist. Both, being dead and neuronal activity are of course measured one way or the other, which means, that both probabilities are prone to errors. 

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