Can theists be rational?

[westprog]

That's exactly why I say using terms like "creator" and "designer" and "fine-tuner" is dishonest. The topic is about belief in God (look at the thread title).

We do not have ANY examples of a god or gods that are known to exist.

The fine-tuning argument works perfectly well for the universe as simulation. Nothing supernatural at all.

 

[RandFan]

IWe should conclude that there is probably a bias in the coins. A billion people, however...

I've not run the numbers and I suspect neither have you but you get the point.

However, in the case of a single instance of 30 heads - with odds of about a billion to one against - we should assume that the likelihood is that there is some kind of bias.

Depends but an unlikely event in and of itself is of no real significance. Unlikely events happen each and every day. If they didn't we would live in a very strange world. Winning a lottery that is 1 in 41 million like the California Super Lottery is a very unlikely event. I can safely say it will never happen to you. I can't say that it will never happen to anyone though and that is my point.

 

[blobru]

I believe the fine-tuning argument defines H as "a god exists" and E as "the universe is fine-tuned." It then assumes a probability for P(H) (the prior probability that a god exists) of 1 in a million. Probabilities for P(E|H) (the probability that the universe is fine-tuned given a god exists) and P(E|~H) (the probability that the universe is fine-tuned give no god exists) are assumed to be "low" and "really, really low" respectively. You could use your number 4.5 x 10^-37 for P(E|~H) although the original argument assumes it to be much lower (I don't know the basis for the probability of P(E|~H) in the premise, but yours may higher because of your assumption that the strong nuclear force could have only been 50% stronger or weaker than it is).

I'm sure it is. The whole thing is based on assumptions which we need to fudge to get it to mean anything at all. (And thanks for responding, Bri; I quoted your post to make use of the wiki figures, not because I thought you believed it was a sound argument for god.)

You're right, the argument is usually set up with E = fine-tuning and H = God. In another thread it was set up as I had; the advantage to setting up the argument this way is it avoids assigning highly problematic probabilities to God initially (you sneak him in after for "fine-tuning"); instead, it allows you to relate P(E) to P(H); unfortunately (for the argument) it also reveals it's meaningless. P(E) = fine-tuning = 4.5 x 10^-37 (to use my assumptions) gives us no information about P(H): what is the connection between God and fine-tuning? If we assume the sort of god most theists believe in, a necessary god who needs to be worshipped, then P(H) = 1, P(E|H) = 1, and P(H|E) = 1 / 4.5 x 10^-37 >>>> 1. To make the argument probabilistically consistent, we have to at least come up with values for P(E|H) and P(H) such that P(E|H)P(H) < 1. Thus, P(E|H) or P(H) < square_root(P(E)) = 6.7 x 10^-19; i.e., either P(H) < 6.7 x 10^-19 (based on what? where are we getting values for god's existence accurate to 20 decimal places?) or P(E|H) < 6.7 x 10^-19 (again, based on what? other than the need to fudge P(E|H) so P(H|E) < 1, that is); neither, as far as I can tell, has any relation to any plausible estimate of objective fact or subjective belief.

Anyway...I agree with your objection to the premise. I don't think the argument provides any valid support for a belief in a god because I disagree with the premise and therefore the conclusion. However, the argument itself is a valid argument, and if you accept the premise the conclusion would be valid.

Similarly, an argument for aliens based on Drake's equation would suffer from the same problems -- there is no basis for values placed on many of the variables in the premise.

-Bri

I haven't been following the Drake debate too closely, but it seems to me the only thing either Drake or Bayesian fine-tuning can ever show is what values, based on what assumptions, are required for alien life or [a fine-tuning] God to likely exist. One still has to argue for the "rationality" (beyond the trivial point of deductive validity) of the logic's assumptions. I don't think there is a good argument to be made for the rationality of any set of assumptions and values that make Bayesian fine-tuning "probabilistically consistent" (even using posterior probability < 1 as the sole criterion).

 

[Bri]

Bri, I've no interest in lying or obfuscating.

I believe you, as I said. And I accepted your apology sincerely.

I don't care at all about any of this. Fine tuning is being used because of the "improbability" of the universe being fine tuned.

That's not quite right. It's based on the assumption that it is more likely that the universe would be fine-tuned by a god than by some other means. In that regard, it's similar to the assumption that it's more likely that a building on Jupiter would be there because of an intelligent being rather than by some other means.

It doesn't prove anything. It doesn't indicate anything. However, I'm willing to entertain that it does for the purpose of argument and Bayes Theorem. At the end of the day you have to contend with the possibility of an oscillating universe or infinite number of universes which render the theorem meaningless, IMO.

I completely agree. I've never said that the fine-tuning argument proves anything, or even that its conclusions are valid. They are only valid if you accept the premises. I don't personally accept the premises. I similarly don't accept the premises of an argument for the existence of aliens.

However...and this is the important part...a reasonable person could disagree with me on either count.

That said, I understand that you are not defending Bayes theorem. I understand that your point is that deficiencies with Bayes theorem as it relates to a fine tuner, are, at least somewhat, comparable to Drakes equation.

Well, I am actually defending both Bayes theorem and Drake's equation, but not defending arguments based on them. Both are sound as long as you input valid numbers. But neither the fine-tuning argument based on Bayes theorem nor an argument for ET intelligent life based on Drake's equation can include valid numbers because there isn't enough evidence to support any particular set of numbers, and therefore the conclusions are suspect.

I agree that Drakes equation is not capable of giving us a reliable probability but I don't think we can then say that the two are equivalent. They aren't.

They're not the same, but they're not different in any way that I can think of that would be relevant to labeling them "rational" or "irrational."

-Bri

 

[Bri]

Oh, that is so cool. I honestly didn't know. Please to tell me this theory? BTW: if true, I see a nobel prize in your future.

I didn't say I had a theory. I said it was theoretically possible (meaning "hypothetically possible" or "not theoretically impossible"), although I may be unfamiliar with the way you're using the phrase. Can you please define the phrase in such a way that it would be theoretically impossible for a god to exist?

The possibility of an abstract concept based in theory (a set of facts that relate to each-other). The ability to employ mathematical models and abstractions of physics in an attempt to explain experimental data taken of the natural world. In this case the abstraction would be a fine tuner and the data would be the apparent fine tuning of the universe.

I'm dying to see the theory for god BTW. Thanks in advance.

Why don't you provide a theory by which a god would be impossible? If your theory is sound, then I'll agree that it would be theoretically impossible. Otherwise, if there's no theory that makes it impossible, it's theoretically possible.

I'm dying to see the theory that makes a god impossible BTW. Thanks in advance.

-Bri

 

[westprog]

I've not run the numbers and I suspect neither have you but you get the point.

It's just x to the y on calc. But I do indeed get the point.

Darren Brown, the English stage magician and illusionist, filmed himself throwing ten heads in a row. I figured out how he did it - without biased coins or cutting away. However, if he'd filmed himself throwing 30 heads in a row, I'd have been reasonably certain that he was cheating in some way.

Depends but an unlikely event in and of itself is of no real significance. Unlikely events happen each and every day. If they didn't we would live in a very strange world. Winning a lottery that is 1 in 41 million like the California Super Lottery is a very unlikely event. I can safely say it will never happen to you. I can't say that it will never happen to anyone though and that is my point.

I still consider that if 1-2-3-4-5-6 came up on the lottery, (in that order, btw, which increases the odds significantly) then the likelihood is that the fix was in - why, I don't know. If only one person bought a lottery ticket - and still won I'd suspect the fix was in.

 

[fls]

What claim are you claiming one makes and the other doesn't?

The argument for God takes the prior probability of God and considers the posterior probability in light of new 'evidence'. There isn't any evidence being presented for aliens. I made up something similar to serve as evidence - i.e. the great red spot on Jupiter - but it seems pretty clear from the subsequent discussion that you didn't take the idea seriously, nor did you come up with any real observations that have been taken as evidence of aliens (coming up with something or other about giraffes, instead, which I'm pretty sure was made up (at least, a google image search for "giraffe" and "jupiter" didn't come up with anything)). So the one argument claims there is 'evidence' for God and the other makes no claims for evidence of aliens.

If you use Drake's equation to support the claim that intelligent aliens exist, then it's as much a problem as a similar argument for a god.

Drake's equation serves as an estimate for p(H). At least, it's a better attempt than "a million to one" or an "agnostic p=0.5". Other than that, there don't seem to be any other claims associated with the use of Drake's equation - specifically, that aliens exist. Exploring a hypothesis is not the same as forming a belief. Speculating on what kind of observations would serve as evidence is not the same as stating that those observations can be assumed to have been made.

Wow, now I'm really confused. We were talking about an argument that makes a claim about the existence of aliens on Jupiter based on a building or giraffe on the surface of the planet. I think you were trying to equate it to the fine-tuning argument. Both seem to make a claim. Are both irrational? I find the claim about the aliens to be rational if we accept the premises that the building or giraffe would have a much higher probability of being there if an alien was there than if there was no alien.

-Bri

The fine-tuning argument claims that God's existence is more likely based on the presentation of 'evidence'. If there was reference to some observation (like the great red spot), then the alien argument would be that the existence of aliens is more likely based on the presentation of that 'evidence'. In both cases, the extent to which the observation supports the hypothesis, or estimations of prior probability, are worthy of discussion. I have already mentioned that I consider estimations of priors based on scientific inquiry (Drake's equation represents such an attempt) a rational process. No one has yet proposed a prior based on scientific inquiry for God (references to fine-tuning don't count (I apologize for feeling compelled to say something so trivially obvious)).

The next step is to turn to the evidence. Does the presence of the great red spot serve as evidence for aliens? Would the presence of something giraffe-like or building-like in appearance serve as evidence for aliens? If and when anyone seriously presents some observation as evidence for aliens, then it would be reasonable for us to discuss it. Until then, it should be obvious that our prior probability remains unchanged.

Does fine-tuning serve as evidence for God? Well, even if you haven't grasped the meat of the complaints about the fine-tuning argument, you can still probably recognize that the 'evidence' is considered suspect - it's not considered persuasive to those whom it is meant to persuade.*

So on the one hand we have an estimation of a prior based on scientific inquiry, and a search for evidence. And on the other hand we have a claim based on a prior pulled from someone's ass and suspect 'evidence'. I have no difficulty seeing a difference between the two on the basis of what sorts of claims are made and the extent to which they are supported.

Linda

*Technically, I don't think that is true, since it appears that the fine-tuning argument is really meant to resolve cognitive dissonance for those who wish to consider the idea of God rational, rather than to find something convincing to non-believers.

 

[yy2bggggs]

Well, I am actually defending both Bayes theorem and Drake's equation, but not defending arguments based on them. Both are sound as long as you input valid numbers.

The main problem is in the usage of Bayes Theorem in the first place, not the numbers you plug in.

They're not the same, but they're not different in any way that I can think of that would be relevant to labeling them "rational" or "irrational."

Except that in the case of extra terrestrial intelligence, you know that the means exists, and in the case of fine tuners, you do not.

 

[Bri]

neither, as far as I can tell, has any relation to any plausible estimate of objective fact or subjective belief.

The values assumed in the premise of the argument are:

P(H) = 0.000001 (1 in a million)
P(~H) = 0.999999
P(E|H) = 0.000001 (1 in a million)
P(E|~H) = 0.0...{a bajillion zeros}...1

I think some might surmise a higher probability of a god existing P(H) and of fine-tuning if a god exists P(E|H). I'm sure the argument assumes a much wider range of possible values of the universal constants to arrive at P(E|~H) than you did. But it might also be noted that these values yield a near-100% probability of the existence of a god, whereas you probably really only need to yield a 50% or higher probability of existence.

Your math skills are probably better than mine, so if you assume P(H) = 0.000001, P(~H) = 0.999999, and P(E|H) = 0.000001 you would need P(E|~H) to be 10^-12 or so to get 0.5 for P(H|E) wouldn't you?

I haven't been following the Drake debate too closely, but it seems to me the only thing either Drake or Bayesian fine-tuning can ever show is what values, based on what assumptions, are required for alien life or [a fine-tuning] God to likely exist. One still has to argue for the "rationality" (beyond the trivial point of deductive validity) of the logic's assumptions.

Yes, I completely agree. That has been my point all along.

I don't think there is a good argument to be made for the rationality of any set of assumptions and values that make Bayesian fine-tuning "probabilistically consistent" (even using posterior probability < 1 as the sole criterion).

I don't know if that's true or not, but the same could be said for an argument for aliens based on Drake's equation. Too many of the variables are mere speculation. We simply don't know enough about the conditions (and possibly unlikely events) by which intelligent life emerged on this planet to justify any set of values that will result in a probability of extra terrestrial intelligent life greater than 0.5.

-Bri

 

[yy2bggggs]

Your math skills are probably better than mine, but if you assume P(H) = 0.000001, P(~H) = 0.999999, and P(E|H) = 0.000001 you would need P(E|~H) to be 10^-12 or so to get 0.5 for P(H|E) wouldn't you?

P(H AND E)=P(H)P(E|H)=10^-12With A=H AND E, and C=H' AND E, P(H|E)=A/(A+C). For 1/2, you need C=A=10^-12.

Now, C=P(H')P(E|H'). So 10^-12=0.999999P(E|H'), so you would need P(E|H') to be 10^-12/0.999999.

But it's still abuse. You're in a much better position to up and estimate P(H|E) than P(H) in the first place... these terms, plus the other assumptions you have to make, are attempts to pound a square peg into a round hole.

To emphasize my point... do you even know if you have the order right for P(H)? It's going to matter tremendously as to what P(H|E) is going to calculate.

I don't know if that's true or not, but the same could be said for an argument for aliens based on Drake's equation. Too many of the variables are mere speculation.

That's true. It's a bunch of extrapolation from a single data point.

We simply don't know enough about the conditions (and possibly unlikely events) by which intelligent life emerged on this planet to justify any set of values that will result in a probability of extra terrestrial intelligent life greater than 0.5.

And it goes the other was as well. We don't know enough about the conditions (and possibly unlikely events--still don't even have to change this) by which intelligent life emerged on this planet to justify any set of values that will result in a probability of extra terrestrial intelligent life less than 0.5.

That doesn't erase anything you have said, mind you--what you said is still completely true.

BUT....

...we know the conditions can actually exist. We know the universe really does produce these conditions.

 

[yy2bggggs]

Okay... let's try this way. Drake's equation is not Bayesian. But "there is extra terrestrial intelligent life" is a proposition, much like "there is a fine tuner.

Let H be that there's a god, and E be that the universe is fine tuned. Then
P(H|E)=P(H)P(E|H)/P(E)
...and we stop there. We can't apply this until we know the universe is fine tuned. We could guess... we could speculate. We can make premises that E is true. But it isn't reality based--it's not evidence based--it's speculation based. Any application of the above theorem is premature unless we have good reason to suspect E actually is true.

Now let H be "there is extra terrestrial intelligent life", and E by "there is life". Then
P(H|E)=P(H)P(E|H)/P(E)
...and we can apply a Bayesian inference, because we know E is true. We don't even have to blink. There's no realistic chance we're fooling ourselves. No chance of culling out the actual world by performing this inference.

There's a direct comparison for you. Are you still going to claim this is irrelevant Bri? Sure, in both cases all of the terms are being estimated. But at least in the extra terrestrial intelligence case, we're justified to actually modify our belief.

 

[Bri]

The argument for God takes the prior probability of God and considers the posterior probability in light of new 'evidence'. There isn't any evidence being presented for aliens. I made up something similar to serve as evidence - i.e. the great red spot on Jupiter - but it seems pretty clear from the subsequent discussion that you didn't take the idea seriously, nor did you come up with any real observations that have been taken as evidence of aliens (coming up with something or other about giraffes, instead, which I'm pretty sure was made up (at least, a google image search for "giraffe" and "jupiter" didn't come up with anything)). So the one argument claims there is 'evidence' for God and the other makes no claims for evidence of aliens.

The fine-tuning argument claims that evidence of fine-tuning is evidence of a god. The argument based on Drake's equation claims that evidence of the number of stars, estimates of the average numbers of planets for each star, etc. is evidence of the existence of aliens.

Both claim evidence to support the conclusion, but the problem with both is that some needed evidence is missing -- values that are simply guessed at without much if any supporting evidence. In the argument for a god, one of those values is the prior probability of a god, which I think is the one you're objecting to. It's given at 1 in a million, but could be higher or could be lower. One important point is that the fine-tuning argument makes the prior probability of a god low on purpose, because even if you consider the prior probability low, the posterior probability may still be high consider fine-tuning. Even so, saying that the value is a pure guess is a valid objection to the premise of the argument, similar to objecting that any of the values of Drake's equation are pure guesses.

I can't tell if you're objecting to the use of Bayes analysis in general (the fact that Bayes analysis requires a prior probability that in this case is just a guess). While it's true that if you guess at the prior probability, that the conclusion is also a guess, the same is true of Drake's equation -- if you guess at any value, the conclusion is also a guess.

So it isn't that I didn't take your analogy of the spot on Jupiter seriously. Maybe I'm missing the point of the example, but it simply wouldn't conclude that aliens are probable in a Bayesian analysis unless the spot on Jupiter were something that would be unlikely to occur without aliens (such as a building on Jupiter). So if you were meaning for it to be similar to the argument for god, it would fall short. That doesn't mean that Bayesian analysis couldn't be used with the situation you described, but if you did use it the posterior probability of aliens on Jupiter would be very close to the prior probability, as you would expect because the probability of the spot occurring with or without aliens would be about the same. However, if you used Bayesian analysis with the example of a building on Jupiter, you would get a high probability of aliens having been on Jupiter even if you assume a very low prior probability, as you would expect because there is a higher probability of the building having been there because of aliens than by other means.

Drake's equation serves as an estimate for p(H). At least, it's a better attempt than "a million to one" or an "agnostic p=0.5".

The problem is that an argument based on Drake's equation is not a better attempt because many of the values you would put in are just as much guesses as the prior probability of a god used in the fine-tuning argument.

The fine-tuning argument claims that God's existence is more likely based on the presentation of 'evidence'. If there was reference to some observation (like the great red spot), then the alien argument would be that the existence of aliens is more likely based on the presentation of that 'evidence'.

The evidence in the fine-tuning argument concerns the probability of fine-tuning. Other values are simply guesses.

Drake's equation isn't a Bayesian argument, but like I said you can form a Bayesian argument for aliens based on the red spot or based on a hypothetical building. The hypothetical building would be closer to the argument for a god in that it is assumed that there would be a much higher probability of the building's existence if there were aliens on Jupiter than if there were no aliens on Jupiter. Even though we don't know the precise prior probability of aliens on Jupiter without considering the new evidence, even if you gave a low probability of aliens on Jupiter as a prior probability, you would still get a high posterior probability considering the building. That's why evidence of a building on Jupiter would indeed be evidence of aliens.

No one has yet proposed a prior based on scientific inquiry for God (references to fine-tuning don't count (I apologize for feeling compelled to say something so trivially obvious)).

I understand what you're saying, and you're right. The prior probability is a guess (it is not based on evidence). But your objection is no different than an objection to guesses (also not based on evidence) for values for Drake's equation.

The next step is to turn to the evidence. Does the presence of the great red spot serve as evidence for aliens?

Nope.

Would the presence of something giraffe-like or building-like in appearance serve as evidence for aliens?

Yes, absolutely.

If and when anyone seriously presents some observation as evidence for aliens, then it would be reasonable for us to discuss it. Until then, it should be obvious that our prior probability remains unchanged.

Correct. But we do have evidence of fine-tuning.

Does fine-tuning serve as evidence for God?

Yes, it would if you accept the other premises of the argument.

So on the one hand we have an estimation of a prior based on scientific inquiry, and a search for evidence. And on the other hand we have a claim based on a prior pulled from someone's ass and suspect 'evidence'. I have no difficulty seeing a difference between the two on the basis of what sorts of claims are made and the extent to which they are supported.

The problem is that there is no valid probability of aliens without the missing pieces of the puzzle (which must also be pulled from someone's ass or based on suspect "evidence"). It's the same objection you have to the fine-tuning argument.

-Bri

 

[Bri]

The main problem is in the usage of Bayes Theorem in the first place, not the numbers you plug in.

I disagree.

Except that in the case of extra terrestrial intelligence, you know that the means exists, and in the case of fine tuners, you do not.

We don't know the means for extra terrestrial intelligence to exist, specifically because we don't know the conditions and events by which intelligent life exists here on earth and therefore don't know the probability of those conditions and events having occurred elsewhere. We do know that it is possible that extra terrestrial intelligence exists, and we also know that it is possible that a god exists.

-Bri

 

[yy2bggggs]

We don't know the means for extra terrestrial intelligence to exist,

In bold is your special pleading.

Specifically, you are alleging that the means for extra terrestrial intelligence to exist must somehow be different than the means by which we exist. Whatever caused us to be here would be quite sufficient to cause something else to be here. All that has to happen is that it happens again.

Oh, you can object that we don't know it ever happened again. But that's not the point, is it? (Say yes here and you're back to your modus operandi)


Adding:

The main problem is in the usage of Bayes Theorem in the first place, not the numbers you plug in.

I disagree.

The use of Bayes Theorem is deriving a P(H|E), to form a new P'(H), from a P(H). But you're in a much better position to up and estimate P(H|E) in the first place than P(H). You have to stretch to get a P(H), and the only reason to do so is to plug some P(E|J) in... then you need to make some sort of assumption to make E AND H, E AND J collectively exhaustive in E, such as a new assumption... all to get a P'(H) which you're better to judge directly.

It's abuse, plain and simple. It's not how Bayes is used for any other thing, and for a reason.

 

[RandFan]

That's not quite right. It's based on the assumption that it is more likely that the universe would be fine-tuned by a god than by some other means. In that regard, it's similar to the assumption that it's more likely that a building on Jupiter would be there because of an intelligent being rather than by some other means.

That's what I'm saying. The two instances simply don't equate. They don't equate at all. You need to make all sorts of assumptions that are not warranted by the finding that the universe is fine tuned.

However...and this is the important part...a reasonable person could disagree with me on either count.

Not really, no. The problem with positing a fine tuner is that you are saying nothing. What is a fine tuner? How does it fine tune? Saying there is a fine tuner is the equivelant of saying "then a miracle occurs". You've not said anything.

Humans build structures. We know how they build structures. We understand the usefulness of structures to humans and so we understand the motives for building them. We've seen them before so we know what to compare them to.

What does the order of a snowflake mean?

You can't extrapolate ANYTHING from the fact that the universe is fine tuned. Nothing.

They're not the same, but they're not different in any way that I can think of that would be relevant to labeling them "rational" or "irrational."

• One posits the existence of something we know can exist.
• One posits the existence of something we A.) know nothing about. B.) Don't know if it ever existed. C.) Know would likely violate laws of physics.

One is simply defined as not impossible (arguably) the other we know is possible because inteligent life exists (us). That's how they are different.

Of course you've got to be willing to accept that we know nothing of whether a superman like fine tuner exists and that we don't know how this superman like fine tuner fine tunes.

 

[RandFan]

Can you please define the phrase in such a way that it would be theoretically impossible for a god to exist?
...

I'm dying to see the theory that makes a god impossible BTW. Thanks in advance.

Oh, you are welcome. I aim to please.

First off, it's your claim so it is up to you to show that it is "theoretically" possible. Not for me to demonstrate that it is impossible. Though its rather easy to construct an argument for why why god would be impossible given certain premises, that's not really the point. The point is for you to demonstrate that a "fine-tuner" is theoretically possible. But fine. Let's go ahead with the theorectical problems of such a "fine-tuner"


Let's start with facts that would make it theoretically possible.

• God uses X to travel faster than the speed of light.
• God uses Y method to construct planets and stars.

Starwars and Startrek have spaceships that travel faster than the speed of light. This is not theoretically possible. In order to construct a universe with 300,000,000,000 galaxies god would need to travel at speeds that are not theoretically possible. How does he do that?

The move Starwars had an artifical planet (the death star) There are theoretical problems with such a feat but they pale beyond comprehension to the formation of a star (sun). Just because humans can construct buildings doesn't mean that there is a being out there that can construct stars the mass of the Pistol Star. No theoretical construct exists for the artificial construction of a star.

So, to posit a "fine-tuner" you need to gloss over theoretical problems of physics and simply state "god did it". Until you resolve those physical limitations a "fine-tuner" is simply not theoretcially possible.

So, how does a "fine-tuner" travel many, many times faster than the speed of light and how does a "fine-tuner" overcome the many physical limitations imposed by the laws of physics to make something as big as the Pistol Star that has a mass of 150 M☉.

Now, as for theoretical possibility. For you to be able to demonstrate that god is theoretically possible you need to explain the mechanisms that god uses to create the universe. Until you do that we can't even begin to ascertain whether or not this "fine-tuner" is theoretically possible. It remains conjecture. Nothing more.

BTW: The difficulty that you are having is that in your mind you simply insert a placeholder for god that solves all of the problems. There is a word, I believe, in the movie industry for such a placeholder. Take Superman for instance. In that example it is the Sun that gives him is powers but that isn't an explanation because there is no theoretical explanation for why a yellow sun would allow superman to have the ability to violate laws of phyaics in order to stop a plane in midair. We accept that this is possible because of that placeholder that causes us to suspend our disbelief when in reality it is not possible based on the laws of physics for superman to simply stop a plane in midair.

Now, as for "hypothetical" vs "theoretical". If superman were possesed of the ability to stop a plane in mid air then he could stop a plane in mid air. That is a hypothetically valid statement. Given the premises he could. The problem is that the premise relies on a theoretical impossibility.

 

[Malerin]

Okay... let's try this way. Drake's equation is not Bayesian. But "there is extra terrestrial intelligent life" is a proposition, much like "there is a fine tuner.

Let H be that there's a god, and E be that the universe is fine tuned. Then
P(H|E)=P(H)P(E|H)/P(E)

I agree with Wasp that "The universe is fine-tuned" seems question begging. Change it to "The physical constants are precisely balacned to support life".

...and we stop there. We can't apply this until we know the universe is fine tuned. We could guess... we could speculate.

We can do more than that. Based on evidence from biology and cosmology, we can predict that a universe with no stars or no molecules or no heavy elements would not be life-permitting. This is speculation based on actual scientific evidence. Non-molecular or non-star life is a fairy tale and it would be strange to attack a theistic argument on speculation that has no basis in cosmology or biology.

We can make premises that E is true. But it isn't reality based--it's not evidence based--it's speculation based. Any application of the above theorem is premature unless we have good reason to suspect E actually is true.

Well, we're pretty sure that the constants have to have the precise values they have for life as we know it to exist. Even Stenger admits this in his paper and he is a staunch atheist. Attacking E by imagining strange life forms could exist in a universe with no molecules is more faith-based than believing in God- such speculation actually contradicts everything we now about life.

There are three ways to argue against (E):
1. The constants don't need to have the precise values they do to produce a universe capable of supporting life.
2. Life is much more adaptable than we give it credit for, and would emerge in universe we currently think are inhospitable
3. There are an infinite (or nearly infinite) number of universe and we happen to be in one where the values are life-permitting. We got lucky, in other words.

(1) and (2) are pure speculation and actually run counter to our understanding of cosmology and biology. Stenger has a program called "MonkeyGod" where he tries to show that changes in four constants could produce a life-permitting universe. Try it. I couldn't come up with anything that would support life as we know it, and there are 20+ constants the program simply ignores. http://www.colorado.edu/philosophy/vstenger/Cosmo/monkey.html
(3) is the real defeater of the argument, but (3) is speculation based so far as well. There is no evidence so far that there is more than just this universe.

It would be rational for a person to believe there is just this one universe. For such a person Pr(E/H) >> Pr(E/~H). In other words, going by what we know of cosmology and biology, and not believing in more than one universe, the values of the physical constants are better explained by a universe creator than by chance alone.
OTOH, it would be rational for a person to believe we are part of a multiverse of universes and we just got lucky with the constants being the way they are.

 

[yy2bggggs]

In order to construct a universe with 300,000,000,000 galaxies god would need to travel at speeds that are not theoretically possible. How does he do that?

Uhm, not really. Everything in the observable universe was at a single point in time. God merely has to be really damned smart about it, and create everything locally around this time. God's often presumed to be outside of time and space, so this should be no problem (furthermore, there's no need for God to travel through space if this is the case, so motion isn't an object).

But God still has to do it by using some actual power he has, that works some way--some way we're not sure is even possible in the first place.

But rational people ignore such minor technical details.

 

[fls]

The fine-tuning argument claims that evidence of fine-tuning is evidence of a god. The argument based on Drake's equation claims that evidence of the number of stars, estimates of the average numbers of planets for each star, etc. is evidence of the existence of aliens.

Nope, that is not the argument. Drake's equation is simply an attempt to estimate a prior. There is no claim that the existence of a planet is evidence of the existence of aliens.

Both claim evidence to support the conclusion, but the problem with both is that some needed evidence is missing -- values that are simply guessed at without much if any supporting evidence. In the argument for a god, one of those values is the prior probability of a god, which I think is the one you're objecting to. It's given at 1 in a million, but could be higher or could be lower. One important point is that the fine-tuning argument makes the prior probability of a god low on purpose, because even if you consider the prior probability low, the posterior probability may still be high consider fine-tuning. Even so, saying that the value is a pure guess is a valid objection to the premise of the argument, similar to objecting that any of the values of Drake's equation are pure guesses.

If your approach is rational, you start by asking what sort of information you need to make an informed guess. If your approach is not rational, you start by asking for the strength of someone's belief. I have no difficulty seeing a difference between the two.

I can't tell if you're objecting to the use of Bayes analysis in general (the fact that Bayes analysis requires a prior probability that in this case is just a guess). While it's true that if you guess at the prior probability, that the conclusion is also a guess, the same is true of Drake's equation -- if you guess at any value, the conclusion is also a guess.

I'm saying that a rational approach to the use of Bayes' analysis involves using priors that are as informed as possible.

So it isn't that I didn't take your analogy of the spot on Jupiter seriously. Maybe I'm missing the point of the example, but it simply wouldn't conclude that aliens are probable in a Bayesian analysis unless the spot on Jupiter were something that would be unlikely to occur without aliens (such as a building on Jupiter). So if you were meaning for it to be similar to the argument for god, it would fall short. That doesn't mean that Bayesian analysis couldn't be used with the situation you described, but if you did use it the posterior probability of aliens on Jupiter would be very close to the prior probability, as you would expect because the probability of the spot occurring with or without aliens would be about the same. However, if you used Bayesian analysis with the example of a building on Jupiter, you would get a high probability of aliens having been on Jupiter even if you assume a very low prior probability, as you would expect because there is a higher probability of the building having been there because of aliens than by other means.

I'm mostly just pointing out that no one is offering up evidence in support of the existence of aliens, since no one has offered up the kind of information you or I describe above.

The problem is that an argument based on Drake's equation is not a better attempt because many of the values you would put in are just as much guesses as the prior probability of a god used in the fine-tuning argument.

I realize that you do not understand the difference between something formed without any information whatsoever, and something formed from systematic observation. I'm just saying that I have no difficulty understanding the difference.

I understand what you're saying, and you're right. The prior probability is a guess (it is not based on evidence). But your objection is no different than an objection to guesses (also not based on evidence) for values for Drake's equation.

I'm guessing that you have no experience with forming priors.

Linda

 

[westprog]

In order to construct a universe with 300,000,000,000 galaxies god would need to travel at speeds that are not theoretically possible. How does he do that?

If one is deducing the existence of God from the values he gave to the laws of physics (something I am not doing) then it doesn't make sense to limit him by the laws which he has defined.