Can theists be rational?

This is basically the Bayesian vs. Frequentist argument over what a probability is.

Frequentists consider a probability (distribution) to be valid only if it can be obtained from a sample.

Bayesians are more relaxed and believe a purely subjective probability (distribution) is a valid starting point.
 
It assumes it can, not that it does? :) A 100% chance the Purple Puffing can exist would presume existence. A 5% chance merely postulates the possibility thereof.
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cj x

It assumes it can, not that it does? :) A 100% chance the Purple Puffing can exist would presume existence. A 5% chance merely postulates the possibility thereof.

...snip...

No and this seems to the thing that Bri and yourself are struggling to understand when you use these "5% probability" statements.

Try it from this approach:

Can I ever say that for a standard die that there is a "1 in million chance that I can roll a zero"?

The answer has to be "no" and the reason why you have to say no is that a die does not contain a "zero side" since it does not exist.

As soon as you state that something has a probability of "existing" you are assuming it can exist therefore when you shove that into an argument about whether something exists or not you have already assumed it can exist.
 
This is basically the Bayesian vs. Frequentist argument over what a probability is.

Frequentists consider a probability (distribution) to be valid only if it can be obtained from a sample.

Bayesians are more relaxed and believe a purely subjective probability (distribution) is a valid starting point.

I don't think it is - it's just a matter of looking at the assumptions that are being brought to the table when we state the chances of something happening or existing is.

For instance I can start an argument with the premise that the chances of winning the UK lottery are 1 in 14 million but only because the UK lottery exists and can be won.

In the purple puffer and like examples it is quite a different matter as the argument is meant to lead to a conclusion about whether something exists or not so if we start with a premise that contains the assumption that it can exist (or can't exist) then it is simply a circular argument.
 
Darat is right. You cannot wish a probability onto god any more than you can wish a probability on the IPU. Either consciousness can exist outside of a material brain--in which case any and all such gods, demons, Thetans, angels, incubis, ghosts, etc. are a probability-- or it can't happen.

Either some sound somewhere can exist in a vacuum... or it cannot happen.

You can't put a probability on an impossibility. You must first show it to be logically possible for consciousness to exist outside of a brain before you can make any assumptions about what it is or does. Otherwise it's all conjecture based on an impossible presumption. Magical thinking.
 
So the problem is not the subjectiveness of the probability, but rather the logically inconsistent definition of God which makes the only reasonable estimate of the prior probability zero if God has to obey logic. Does it?
 
So the problem is not the subjectiveness of the probability, but rather the logically inconsistent definition of God which makes the only reasonable estimate of the prior probability zero if God has to obey logic. Does it?

It's the start of a new week help me out! I just can't make sense of this...
 
In the purple puffer and like examples it is quite a different matter as the argument is meant to lead to a conclusion about whether something exists or not so if we start with a premise that contains the assumption that it can exist (or can't exist) then it is simply a circular argument.

I'm not sure why you think that the Purple Puffing example assumes that the Purple Puffing definitely exists. It seems just the opposite to me -- that it assumes that it probably doesn't exist, but leaves open the possibility that it might exist.

It seems that the probability would have to be 100% if you were to assume that the Purple Puffing exists.

Likewise, a probability of 0% would assume that it can't or doesn't exist. A probability between 0% and 100% would mean that it might exist but it might not.

You can't put a probability on an impossibility.

Yes you can. The probability of something occurring that is impossible is 0%. You seem to be missing the point. You have a valid opposition to the probability placed on existence in the premise, but that's not what we're talking about here. If you think that the existence of a god is impossible, that's a completely different argument from the one Joe and Darat are making.

-Bri
 
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No and this seems to the thing that Bri and yourself are struggling to understand when you use these "5% probability" statements.

Try it from this approach:

Can I ever say that for a standard die that there is a "1 in million chance that I can roll a zero"?

The answer has to be "no" and the reason why you have to say no is that a die does not contain a "zero side" since it does not exist.

As soon as you state that something has a probability of "existing" you are assuming it can exist therefore when you shove that into an argument about whether something exists or not you have already assumed it can exist.
You mean by standard die a six sided die? I usually use 10 sided ones being an Ars Magica author, and yes there is a 1 in 10 chance one will roll a '0' on that.

OK, yes I fully understand your argument. A zero can not be a possibility on a six sided die (assuming a standard one numbered 1 to 6 - I have plenty of six sided dice with zeros on in my dice collection).

So you are saying that the premise that X is a 1 in whatever chance fails, because X does not exist. So one has to postulate known entities for X to have any meaning? That is true if you use a Frequency interpretation of probability sure - but not if you use Classical, Logical, or Subjective bases for probability. This is not a frequency probability.

I actually mentioned this about six pages back when I linked to the article on Interpreting Probability in the Stanford Encyclopedia of Philosophy. I think most people never followed the link, because they assumed my comment that our understanding of probability was problematic to mean "we are not very good at understanding probability" - true enough, but not at all what I meant --
http://plato.stanford.edu/entries/probability-interpret/

Bayesian theorems use Evidential Probability - not Frequentism. Philosophers of mathematics disagree on whether Evidential Probability is based on the Logical, Epistemic, Classical or Subjective interpretation of Probability, but one thing they all agree on is that it is not a Frequency Probability. So the die analogy, which is a classic example of postulating probability in frequentist terms, fails if applied to a Bayesian theorem.

Somehow I rather suspect Ivor and Linda know far more about maths and probability than I ever will - and they should be able to confirm if I am making these terms up, or if I am in fact completely correct. :)

I'll get back to discussing Joes objections late tonight - still working flat out on book, just dropped in to say hi.

cj x
 
If anyone is interested (and maybe this was posted before in this thread and I missed it) Wikipedia has a much briefer overview of Bayesian Probability here: http://en.wikipedia.org/wiki/Bayesian_probability

I also e-mailed one of the people cited as the author of the argument cj posted. I asked him if indeed he is the author of the argument, and if so for his comments. I'll post his response if I receive it.

-Bri
 
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...snip...

So you are saying that the premise that X is a 1 in whatever chance fails, because X does not exist.

...snip...

Not at all, I am making no comment on whether your premise is correct or incorrect simply on what your premise actually means. If you start an argument with a premise such as "1 in a million" an implicit assumption in that premise is that it can or does exist. Therefore you start your argument assuming what you claim your argument concludes i.e. whether something exists or not.

This is why Joe has stated repeatedly that it doesn't matter what you plug into your argument it "proves" it exists or even that "non-god exists", it's the argument that is flawed.
 
If you start an argument with a premise such as "1 in a million" an implicit assumption in that premise is that it can or does exist.

Can and does are two different things. Is the assumption that the Purple Puffing does exist or only that it can exist?

-Bri
 
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That is why I used both the words in my post....

I agree that it assumes that the Purple Puffing can exist. Joe is saying that it assumes that the Purple Puffing does exist.

ETA: So is the assumption that the Purple Puffing does exist or only that it can exist?

-Bri
 
Not at all, I am making no comment on whether your premise is correct or incorrect simply on what your premise actually means. If you start an argument with a premise such as "1 in a million" an implicit assumption in that premise is that it can or does exist. Therefore you start your argument assuming what you claim your argument concludes i.e. whether something exists or not.

This is why Joe has stated repeatedly that it doesn't matter what you plug into your argument it "proves" it exists or even that "non-god exists", it's the argument that is flawed.


Nope the argument, as i repeatedly have pointed out (and also it's not my argument: I just chose it to illustrate a rational argument for theism - It;'s from Forster & Marston as I said - curiously I did post another logical argument for theism in the same thread, linked, but no one took me up on mine) does not postulate the conclusion as a starting premise. It postulates one of two possible conditions: in short it defines subjective probabilities, fo ruse in the Bayes Theorem. As both alternatives are offered, it avoids the problem of Petitio Principii

cj x

 
If anyone is interested (and maybe this was posted before in this thread and I missed it) Wikipedia has a much briefer overview of Bayesian Probability here: http://en.wikipedia.org/wiki/Bayesian_probability

I also e-mailed one of the people cited as the author of the argument cj posted. I asked him if indeed he is the author of the argument, and if so for his comments. I'll post his response if I receive it.

-Bri


Thanks Bri - I did not think of Wiki, but
http://en.wikipedia.org/wiki/Probability_interpretations
http://en.wikipedia.org/wiki/Philosophy_of_probability
are useful too.

cj x
 
I'm terrible at statistics, but just so I understand, is the argument that any non-zero answer for the probability of something existing already assumes existence? So, a 1 in a million chance assumes existence because it is not a non-zero probability? Or, in other words, for existence, the answer is either "yes" or "no", so it makes no sense to speak of probabilities?
 
Rolling a number other than 1-6 on a six-sided die does not have a 0% probaility (even assuming the die is numbered 1-6). It is possible for the numbers to change on the die as soon you toss it (e.g., through sudden migration of atoms, God's intervention, a capricious alien, etc.).

The only propositions given 0% probailities are logical contradictions (or possibly false math statements).
 
It's the start of a new week help me out! I just can't make sense of this...

I was thinking of Linda's suggestion for a definition of God which explicitly states it is unlawful. Restricting the set of possible gods to those which can be logically defined (i.e. have a definition which obeys the rules of logical reasoning) may not be reasonable. If so it would be possible to assign a subjective probability to the existence of an unlawful god.
 

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