Can theists be rational?

And so far I haven't actually seen, including in your quote, a clear indication that fls has stated that Bayes Theorem was a tautology.

You fail at reading comprehension.

Post 825:

Bayes' theorem (p(H/E)=p(E/H)p(H)/p(E)) itself is a tautology.


If there was any doubt FLS thought Bayes was circular (which was and is my claim), it was certainly dispelled by this:

Which are entirely dependent upon p(H/E).

The problem with circular arguments is that you can't always recognize that you've said the same thing twice when it's put into a form that superficially looks different, but is actually equivalent.

But there was no doubt in the first place, was there? You just didn't bother to read far enough back.
 
You fail at reading comprehension.

Post 825:

If there was any doubt FLS thought Bayes was circular (which was and is my claim), it was certainly dispelled by this:

But there was no doubt in the first place, was there? You just didn't bother to read far enough back.

We've cleared it up, though. :)

Linda
 
You fail at reading comprehension.
No, editing my post before posting. That should read:
And so far I haven't actually seen, including in your quote, a clear indication that fls has stated that Bayes Theorem was a tautologycircular.

And yes, I've been keeping up with this thread.
 
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No, editing my post before posting. That should read:


And yes, I've been keeping up with this thread.

Hmm, an edit that occurs conveniently after my post, which pointed out a mistake you made. What was it you said?

Tautology is spelled starting with the letter "T". Circular starts with an entirely different letter--"C". So if someone uses the "T" word, they probably are not talking about the "C" word.

Good advice for yourself.
 
Hmm, an edit that occurs conveniently after my post, which pointed out a mistake you made.
(Edited--rephrasing)
Malerin:

Thank you for your feedback. I have made the appropriate correction to my post.
 
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Me neither. So what gave us the idea that there may be extra-terrestrial intelligent life if it wasn't the presence of terrestrial intelligent life?

I'm sure the idea of elephants gave someone the idea that there may be invisible elephants too, but I'm not sure that necessarily makes arguments for invisible elephants rational.

I do not understand the relevance of your comment.

I'm saying that we're talking about a hypothetical argument that is based on Drake's equation, but concludes a probability of the existence of extra-terrestrial intelligent life.

If that's how you read it, then you misunderstood. I meant that we got the idea that intelligent life may be present in this galaxy from our own presence (unless you have another suggestion), so we start by considering what we can learn from our own presence. It doesn't mean that we believe that there is life elsewhere without evidence, but it sets a higher prior probability than if we weren't here (leaving out the inherent contradiction in that :)).

I understand now what you meant, but I have to disagree that the presence of African elephants necessarily affects the rationality of an argument for invisible elephants.

That doesn't even make any sense. At no point have I suggested that we should start believing in entities with imaginary and previously undiscovered qualities. I actually thought I was arguing the opposite.

The one "previously undiscovered quality" between African elephants and invisible elephants is that one isn't visible. The one "previously undiscovered quality" between extra terrestrial intelligent life and terrestrial intelligent life is that one isn't terrestrial. I'm not sure what you're trying to point out here.

I don't think the sticking point is 'beings', rather I think it is 'supernatural'. If we haven't ever come across any observations that are necessarily capricious or unlawful, why would we have any expectation of doing so in the future?

If we haven't ever come across any observations of intelligent life that are necessarily extra-terrestrial, why would we have any expectation of doing so in the future?

Is there any point to the argument, then? Otherwise, aren't we just saying something like, "this observation is not fully explained, therefore it suggests our explanation is incomplete"? It seems a trivial insight, since it can and is said about pretty much everything we're trying to study.

Well, the point of the argument would be that if you accept the premises, then it is probable that a god exists. Of course, rejection of the premises will always lead to rejection of the conclusion. The same can be said of our hypothetical argument for the existence of aliens using Drake's equation.

What do you think is more plausible - that I will discover a new species of insect in my backyard, or that I will discover a new species of large hominid in my backyard (given that it mostly consists of pool, deck and some small plants and grass)?

I'm not sure what this has to do with anything, but I would consider it more plausible that you would discover a new species of insect in your backyard.

I think people's beliefs are qualified by information as to how likely it is that they exist.

Please answer my question. Do you think there are people who are of the opinion that aliens exist?

Your addition about qualification of the belief seem to agree with the idea that the rationality of a particular belief has more to do with the strength of the belief being proportionate to the evidence for it than the belief itself. In other words, a belief based on little evidence (gods, aliens, or otherwise) should be more an opinion that a statement of positive knowledge.

People generally. I don't think people 'believe' in aliens in the same way that they 'believe' in elephants. I think it's more like the way in which we 'believe' in the possibility of undiscovered rodent species (except more exciting).

I'm not sure what you mean here. I just asked if there are people who are of the opinion that the existence of aliens is probable. The next question would be are those beliefs necessarily irrational, and if not why not?

I think the problem is with trying to consider it as an all-or-none type of situation.

I completely agree with you here. That's pretty much what I've been getting at the whole time. You can't just say that a particular belief is irrational and another one is rational. You have to have more information such as why the person believes it, and how strongly she or he believes it.

In other words, belief in a god is not necessarily irrational unless the person has irrational reasons for believing it, or thinks that the evidence is stronger than it really is.

Information.

What kind of information if not information based on evidence?

So these 20+ pages attacking the argument itself don't count?

So far I've seen a lot of attacks on the premises, and a couple of assertions that the argument is either a tautology or an example of circular reasoning. It's actually neither, but a tautology and circular reasoning are two different things.

I'm just saying that we're talking about opinions qualified by scientific inquiry. We aren't certain about aliens, but there is something in between certainty and no-idea-whatsoever.

It's true that we aren't certain. I'm not sure what the gap is between "no idea whatsoever" and merely "uncertain." We're closer to "uncertain" for some pieces of the puzzle, but closer to "no idea whatsoever" on the over-riding question of whether the existence of intelligent extra terrestrials is probable.

I misunderstood then. I thought you were agreeing that the results of the formula made it more likely that a fine-tuner was present.

I may have misunderstood what you meant. The argument concludes that a fine-tuner is probable if you accept the premises (I don't personally accept the premises).

-Bri
 
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The one "previously undiscovered quality" between African elephants and invisible elephants is that one isn't visible. The one "previously undiscovered quality" between extra terrestrial intelligent life and terrestrial intelligent life is that one isn't terrestrial. I'm not sure what you're trying to point out here.

That a new species of insect is more plausible than a new species of large hominid. Invisibility seems a more unlikely characteristic than 'similar conditions lead to similar outcomes'.

If we haven't ever come across any observations of intelligent life that are necessarily extra-terrestrial, why would we have any expectation of doing so in the future?

'Supernatural' seems a more unlikely characteristic than 'similar conditions lead to similar outcomes'.

Well, the point of the argument would be that if you accept the premises, then it is probable that a god exists. Of course, rejection of the premises will always lead to rejection of the conclusion. The same can be said of our hypothetical argument for the existence of aliens using Drake's equation.

Then I misunderstood your last post - ignore that part of my last post.

Drake's equation can allow one to draw conclusions about the direction of the result. Varying the various factors can make the number of possible intelligent civilizations smaller or larger. The same thing goes for estimating the probability that the physical constants have the value that they have (i.e. how 'fine-tuned' the universe is). Putting aside the uncertainty of some of the inputs, we agree (I think) that the number will vary and that people use the result to attempt to conclude that the possibility of contact with an alien civilization is highly unlikely or reasonably likely, or that the possibility of a universe with physical constants suitable for the formation of life is highly unlikely or reasonably likely.

The difference with the use of Bayes' theorem is that your result will always go in the same direction - once you specify that life is more likely in the presence of a fine-tuner, your posterior probability is always higher than your prior. Malerin kept claiming that this increase in the probability of God, given that there is life, somehow confirmed that the argument was valid. That is, attempts were made to draw conclusions from the result (an increase in likelihood), when the result was simply dependent upon how the argument was set up.

I'm not sure what this has to do with anything, but I would consider it more plausible that you would discover a new species of insect in your backyard.

I just wanted to make sure that it was reasonable to consider some possibilities more plausible than others. :)

Please answer my question. Do you think there are people who are of the opinion that aliens exist?

Your addition about qualification of the belief seem to agree with the idea that the rationality of a particular belief has more to do with the strength of the belief being proportionate to the evidence for it than the belief itself. In other words, a belief based on little evidence (gods, aliens, or otherwise) should be more an opinion that a statement of positive knowledge.

I'm not sure what you mean here. I just asked if there are people who are of the opinion that the existence of aliens is probable. The next question would be are those beliefs necessarily irrational, and if not why not?

I completely agree with you here. That's pretty much what I've been getting at the whole time. You can't just say that a particular belief is irrational and another one is rational. You have to have more information such as why the person believes it, and how strongly she or he believes it.

In other words, belief in a god is not necessarily irrational unless the person has irrational reasons for believing it, or thinks that the evidence is stronger than it really is.

Yes, that is basically what I have been trying to say.

What kind of information if not information based on evidence?

Is this just a matter of semantics?

So far I've seen a lot of attacks on the premises, and a couple of assertions that the argument is either a tautology or an example of circular reasoning. It's actually neither, but a tautology and circular reasoning are two different things.

I agree that there have also been attacks on the premises. However, regardless of how the numbers have been varied, no one has altered the idea that life is more likely in the presence of a fine-tuner. The conclusion has always been present in the premises.

I may have misunderstood what you meant. The argument concludes that a fine-tuner is probable if you accept the premises (I don't personally accept the premises).

-Bri

I was referring to the attempts made to calculate the probability that the physical constants would have the value that they have. That number is free to vary based on each of the inputs. The argument using Bayes' theorem has only been allowed to vary in one direction.

Linda
 
Let’s see if I understand this right.

After millions of years of scientific research, humans haven’t explained everything under the sun, so we should use a sprite in the sky to explain all that is not know.

Is that about right?

Paulhoff is tapped on the shoulder and someone whispers in his ears that scientific research is nowhere near that long and is in fact a fairly new development in human history. So even if we have so far learned a lot by using it, there is a hell of a long way to go.

Let’s see if I understand that right.

Before we go back to using the old sprite in the sky as a very poor explanation for things we don’t know, we should give scientific research more time. After all, after thousands of years of sprites and now a sprite in the sky, which has turned out not to have explained anything at all, we should give scientific research that length of time too. Religion has only made it easy for some people not to ask real questions, read real information and only makes it easy for them not to learn how to use their brain intelligently.

Paul

:) :) :)
 
The difference with the use of Bayes' theorem is that your result will always go in the same direction - once you specify that life is more likely in the presence of a fine-tuner, your posterior probability is always higher than your prior.

Only if fine-tuning evidence actually exists. If the multiverse theory is ever proven (or is belived to be likely), the FT argument goes nowhere, because there would be no reason to believe the values of the physical constants were fine-tuned; it all happened by chance.

Malerin kept claiming that this increase in the probability of God, given that there is life, somehow confirmed that the argument was valid.

The argument was valid from the get-go: classic Bayesian probability calculus.

That is, attempts were made to draw conclusions from the result (an increase in likelihood), when the result was simply dependent upon how the argument was set up.

No, the result was dependent on the evidence of a precise balance of physical constants and claims from cosmologists that life-as-we-know-it could not exist in universes where the values where off by just a little. Just postulating a fine-tuner without evidence of fine-tuning gets you nowhere.
 
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Next time you think I'm wrong, start a new thread about it :)
Why is it so important to you?

Regardless, you're not even wrong. You're confused. And my objection was corrected, not retracted. We're left with this:
Malerin said:
If Bayes Theorem were circular, Pr(H/E) would be derived from Pr(H/E). It's not. It's derived from Pr(H), Pr(E/H) and Pr(E/~H).
...which is nonsense, because it presumes (even hypothetically) that an equation can be circular.

Circular refers to arguments, not equations.

This:
x=(1-x)
...is not circular, and is not a tautology. This:
x=f(f-1(x))
...is a tautology, and is not circular (that there's an x in it on the right hand side doesn't make it circular).

That's very simple, and straightforward. fls and I seem to take simple straightforward corrections just fine. Why do you need entire threads about it?

Honestly, next time I think you're wrong, I'm going to consider simply not saying anything. You'll be happier.
 
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That's very simple, and straightforward. fls and I seem to take simple straightforward corrections just fine. Why do you need entire threads about it?

You're thinking of RocketDodger, not me. When have I ever started a thread about a mistake somebody made?

Honestly, next time I think you're wrong, I'm going to consider simply not saying anything. You'll be happier.

Ah, now you're pouting. If you think somebody's wrong, come out with it, but there's no reason to be arrogant and condescending. It makes you look bad, esp. when you haven't bothered to read the preceeding posts and you also commit the very error you're castigating someone else for, as you did in this thread, and then try to cover it up with a hasty edit after the mistake has been pointed out. Before attending to the splinter in thy neighbor's eye...

If someone defined bayes Theorem as Pr(H/E) = Pr(E/H) x Pr(H) / (Pr(E/H) X Pr(H) + (Pr(H/E) x (Pr(~H)), not only would they be wrong by leaving out Pr(E/~H), the Theorem itself would be hopelessly circular, and would make no sense: you would need to know Pr(H/E) to figure out Pr(H/E), and around and around you go. I obviously don't think Bayes is circular, and the only way I could see fls thinking it was is if she defined it like how I just described, which I agree would make no sense.
 
Only if fine-tuning evidence actually exists. If the multiverse theory is ever proven (or is belived to be likely), the FT argument goes nowhere, because there would be no reason to believe the values of the physical constants were fine-tuned; it all happened by chance.

<snip>

That is not necessarily the case. Another possibility is a (correct) multiverse theory, which predicted universes with fundamental constants set to values very different from the universe we exist in, would tend to support the FT argument. I.e. the theory may hint at something unusual happening when our universe was created.
 
Only if fine-tuning evidence actually exists. If the multi-verse theory is ever proven (or is belived to be likely), the FT argument goes nowhere, because there would be no reason to believe the values of the physical constants were fine-tuned; it all happened by chance.

...snip...

Not necessarily, the argument could then be made why is the "multi-verse" so "designed" to allow for universes with life in them to appear...

It's still turtles all the way down!
 
Only if fine-tuning evidence actually exists. If the multiverse theory is ever proven (or is belived to be likely), the FT argument goes nowhere, because there would be no reason to believe the values of the physical constants were fine-tuned; it all happened by chance.

Not really. That it looks unlikely gave us the idea to look for an explanation - something that would make it more likely or would make it irrelevant. But we can look for something that modifies the probability at any level of prior probability.

The argument was valid from the get-go: classic Bayesian probability calculus.

Simply having a personal opinion that the argument is valid (by which I mean that valid assumptions are made from which to draw conclusions) is not sufficient to tell you whether or not it is. Can you see that saying "it is is valid because my personal opinion is that it is valid" is really just a circular argument?

No, the result was dependent on the evidence of a precise balance of physical constants and claims from cosmologists that life-as-we-know-it could not exist in universes where the values where off by just a little. Just postulating a fine-tuner without evidence of fine-tuning gets you nowhere.

I'm not referring to the part of the argument that estimates just how precisely balanced the physical constants are. I'm referring to your conclusion that the rise in posterior probability confirms that your assumption (the presence of a fine-tuner would make these physical constants more likely than the absence) is valid. All you are really doing is using Bayesian calculus to restate your premise (or alternatively to place your conclusion in your premise).

Linda
 
fls said:
Are you suggesting that no argument based on Bayes analysis can be circular?

I don't think anyone here is saying that all arguments based on Bayes analysis are circular.

I am. :)

I take this back. I was attempting to say something more like "Bayes' analysis provides an opportunity to introduce a circular argument".

Linda
 
If someone defined bayes Theorem as Pr(H/E) = Pr(E/H) x Pr(H) / (Pr(E/H) X Pr(H) + (Pr(H/E) x (Pr(~H)), not only would they be wrong by leaving out Pr(E/~H), the Theorem itself would be hopelessly circular, and would make no sense: you would need to know Pr(H/E) to figure out Pr(H/E), and around and around you go. I obviously don't think Bayes is circular, and the only way I could see fls thinking it was is if she defined it like how I just described, which I agree would make no sense.

Whenever you have two things which are equivalent - in this case, p(H/E) is equivalent to p(E/H)p(H)/p(E) - it gives you an opportunity to essentially say the same thing twice by serving as a disguise. Some people are fooled by disguising the superficial appearance and that forms the basis of a circular argument. Most people aren't fooled by stating the same thing twice in the same form - i.e. the circularity is too obvious. The statement "p(H/E)" doesn't need to be repeated in that exact form in order for the argument to be circular, just something that is equivalent.

Linda
 
If someone defined bayes Theorem as Pr(H/E) = Pr(E/H) x Pr(H) / (Pr(E/H) X Pr(H) + (Pr(H/E) x (Pr(~H)), not only would they be wrong by leaving out Pr(E/~H), the Theorem itself would be hopelessly circular,
From: circular reasoningWP
...in which a proposition to be proved is assumed implicitly in one of the premises
From: propositionWP
...In logic and philosophy, ... Propositions in either case are intended to be truth-bearers, that is, they are either true or false.
From: premiseWP
In discourse and logic, a premise is a claim that is a reason (or element of a set of reasons) for, or objection against, some other claim. In other words, it is a statement presumed true within the context of an argument toward a conclusion.
(Emphasis mine, in all of the above)

P(H|E) is a number--it does not have truth value (true/false)--its value ranges from 0 to 1. The equation, even the wrong one you cited, doesn't qualify for being circular, as it's not an argument, but an equation.
and would make no sense: you would need to know Pr(H/E) to figure out Pr(H/E), and around and around you go.
And you would need to know x to "figure out" x in:
x = f(f-1(x))
...but that doesn't make the above equation wrong, or "hopelessly circular".
I obviously don't think Bayes is circular,
No, but you are using the term "circular" to apply to something it cannot possibly apply to. In addition, fls, as she said, was talking about arguments, not the theorem itself.

The claim about the theorem "not being circular" because P(H|E) doesn't appear on the right is not only nonsense, but it has nothing to do with arguments based on the theorem being circular.
 
Cosmological Fine Tuning has nothing much to do with life though. You can argue CFT without any reference to life at all - just from a universe capable of producing stars f'r instance, and reatin the vast improbabilities.

Why would the presence of stars be any different from the presence of life ? Stars 'evolved' according to the physical laws of their universe, not the other way around. The fact that stars exist are a consequence of those laws. You can't infer from that that the universe is fine-tuned for stars.
 

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