Can theists be rational?

[Bri]

That is not information about gods, though. That is only information about life.

That depends on how it's used. When used in the argument cj posted, it's information about the probability of a god.

Um...no. The information about fine-tuning does not apply to the probability that god exists.

Sorry, but it does. If it's more likely that a fine-tuned universe exists if there is a god than if there is no god, the existence of a fine-tuned universe increases the probability that there is a god.

Let me try an example to illustrate this point.

I'm looking for a disease to name after myself, so I declare that Linda's Syndrome is a condition which leads to a sodium measurement of 118. Out of hundreds of sodium measurements, only a handful will have a measurement of 118. Considering that Linda's Syndrome does not actually exist, does someone with a sodium measurement of 118 make it possible that my idea is true?

Your analogy is the equivalent of assuming multiple universes, whereas the fine-tuned universe argument makes no such assumption. Multiple universes would provide a natural explanation for a fine-tuned universe, which is often used as a basis to attack the probability used in one of the premises. There are similar attacks on the probabilities placed on many of the premises of arguments utilizing Drake's equation.

It's the difference between observing the characteristics of something and assigning a characteristic to something that we have not observed.

As far as I know, there is no evidence that we have observed extra-terrestrial intelligent life.

You have stated that:

"I don't think either proposition is known other than that they are not impossible."

If you cannot make any other distinction between them, this is the same as saying they are "equally unknown".

Obviously we can make some distinctions between them, which is why I'm not sure what "equally unknown" means. I'm just not sure that those distinctions are quantifiable in any meaningful way that would allow you to draw a line and state that belief x is rational but belief y is irrational when the probability of either is unknown.

If we look back at where this quote came from (http://www.internationalskeptics.com/forums/showthread.php?postid=4330750#post4330750) we see that RandFan stated that they were not equally unknown - that one was more plausible than the other. You disagreed with that statement.

Yes, I disagree with that statement according to the definition RandFan posted of "plausible." I'm not sure that it can be determined which is "more plausible" than the other.

I'm not sure that anyone is suggesting that, though. I think the suggestion is that the extent to which an idea is considered plausible reflects the extent to which there is evidence for that idea (or the extent to which it is constrained).

I may be misunderstanding what you mean by "constrained" but neither seems to be "more constrained" than the other by any meaningful definition of "constrained." Nor does it seem to me that either is necessarily "more plausible" than the other by the definition RandFan posted earlier.

-Bri

 

[Bri]

FWIW, you do know that Drake's equation was not put forth as any argument for the existence of ET Intelligence, don't you? It really is there to say, here is what we'd need to know.

I agree, but I suspect that RandFan would disagree with you. The problem is that some people do cite Drake's equation as "evidence" that ET intelligence exists and use it to justify a belief that ET intelligence exists. To argue that the use of Drake's equation makes the belief in ET intelligence "rational" while beliefs based on similar arguments for gods are "irrational" one need to distinguish the two in some meaningful way. I'm not sure there's a reasonable definition of "irrational" that can make that distinction.

Considering a fine-tuned universe?! That's not even part of this argument. (And even asserting that, assumes the existence of a tuner, doesn't it?) If it is, I'll take that on. Are you saying the universe is fine-tuned for the existence of humans?

It's been pointed out several times that the argument in question (the one cj posted) is based on the premise of a fine-tuned universe.

I'm not saying one way or the other. My personal opinion is that the universe is not necessarily fine-tuned (I disagree with the premise of the argument cj posted).

But there is evidence that the universe is fine-tuned for human existence, that as Wikipedia puts it "certain universal physical constants lie within a very narrow range, so that if any of several fundamental constants were only slightly different the universe would be unlikely to be conducive to the establishment and development of matter, astronomical structures, elemental diversity, or life as it is presently understood."

-Bri

 

[Darat]

...snip...

But there is evidence that the universe is fine-tuned for human existence,

...snip...

What evidence is this?

 

[Bri]

http://en.wikipedia.org/wiki/Fine-tuned_universe
http://en.wikipedia.org/wiki/Rare_Earth_hypothesis
http://en.wikipedia.org/wiki/Cosmological_constant#Cosmological_constant_problem
http://en.wikipedia.org/wiki/Hierarchy_problem
http://en.wikipedia.org/wiki/Strong_CP_problem

-Bri

 

[JoeTheJuggler]

http://en.wikipedia.org/wiki/Fine-tuned_universe
http://en.wikipedia.org/wiki/Rare_Earth_hypothesis
http://en.wikipedia.org/wiki/Cosmological_constant#Cosmological_constant_problem
http://en.wikipedia.org/wiki/Hierarchy_problem
http://en.wikipedia.org/wiki/Strong_CP_problem

-Bri

The universe is some 14 billion years old. Humans have existed for only a tiny fraction of that.

Humans live on a planet orbiting a star in no particular special place (there are planets closer to the sun, and planets further away) that's on the spiral arm in no special point in a galaxy of no special place in the universe.

The universe is immensely big--staggeringly big. We occupy only a teeny tiny little bit of it. In fact, most of the universe is completely hostile to the existence of humans. (It's almost as if we evolved to be adapted to the conditions here on Earth and not conditions of most places in the universe.)

Gee, I wonder what age, arrangement and size a universe would be predicted by a Creationist model?

Oh--I don't need to wonder. That was pretty much the model of the universe accepted by most people before science proved otherwise. It was a very small universe--smaller than our current solar system. The Earth was at the center, and it was only some thousands of years old.

Sorry, but it's abundantly obvious from the scale of things that the universe was not fine-tuned for the existence of humans.

 

[Bri]

Sorry, but it's abundantly obvious from the scale of things that the universe was not fine-tuned for the existence of humans.

I won't argue the point since it's off-topic and I don't necessarily disagree.

-Bri

 

[fls]

That depends on how it's used. When used in the argument cj posted, it's information about the probability of a god.

No, it's not. Let's assume that flognorps exist and that they cause babies to be born with red hair. Can you use the frequency of red haired babies as information about the probability that flognorps exist?

Sorry, but it does. If it's more likely that a fine-tuned universe exists if there is a god than if there is no god,

Only because someone decided to assign that characteristic to the idea of God.

the existence of a fine-tuned universe increases the probability that there is a god.

No. If we already knew that there was a fine-tuner that could reasonably be considered God, it increases the probability that we are one of its creations. But if we don't know if there is a fine-tuner that could reasonably be considered God, we still don't know if there is a fine-tuner that could reasonably be considered God.

Your analogy is the equivalent of assuming multiple universes, whereas the fine-tuned universe argument makes no such assumption. Multiple universes would provide a natural explanation for a fine-tuned universe, which is often used as a basis to attack the probability used in one of the premises. There are similar attacks on the probabilities placed on many of the premises of arguments utilizing Drake's equation.

You didn't answer my question.

As far as I know, there is no evidence that we have observed extra-terrestrial intelligent life.

I wasn't talking about extra-terrestrial intelligent life. I was talking about the life we have observed.

Obviously we can make some distinctions between them, which is why I'm not sure what "equally unknown" means. I'm just not sure that those distinctions are quantifiable in any meaningful way that would allow you to draw a line and state that belief x is rational but belief y is irrational when the probability of either is unknown.

Yes, I disagree with that statement according to the definition RandFan posted of "plausible." I'm not sure that it can be determined which is "more plausible" than the other.

I may be misunderstanding what you mean by "constrained" but neither seems to be "more constrained" than the other by any meaningful definition of "constrained."

You agreed earlier that some value were more likely than others. That is an example of "constrained".

Nor does it seem to me that either is necessarily "more plausible" than the other by the definition RandFan posted earlier.

-Bri

I think if you rid yourself of the idea that someone is trying to draw a line between irrational and rational, it would help to make this clearer.

Linda

 

[Belz...]

I guess I'll have to disagree. I don't think either is seemingly valid. I don't think either proposition is known other than that they are not impossible.

You mean, other than the fact that we have at least one known instance of one and not of the other ?

 

[Belz...]

Are you saying that a theist cannot provide any reasons to believe in a god then?

The theist doesn't have any evidence. In other words, he doesn't "know" anything about gods. He thinks he knows, but he doesn't.

Not true. We have information about some of the variables, depending on which argument for a god you're talking about. For example, we have information about how "fine-tuned" the universe might be.

But we don't. You don't have any way to say if it's fine-tuned or not. The universe evolved based on its physical laws, not the other way around.

 

[Belz...]

No. Because the premises of that argument include the conclusions.

You have inhuman patience, my friend. I don't think you'll manage to get through to bri even after 50 attempts.

The argument starts with the assumption of a probability that God exists and concludes with a probability that God exists. It really is circular.

Or 51.

 

[Belz...]

Sorry, but it does. If it's more likely that a fine-tuned universe exists if there is a god than if there is no god, the existence of a fine-tuned universe increases the probability that there is a god.

IF. That's a big IF. But then again, you'd still be wrong.

As far as I know, there is no evidence that we have observed extra-terrestrial intelligent life.

There is evidence for intelligent life. That's already a step ahead of the competition.

Yes, I disagree with that statement according to the definition RandFan posted of "plausible." I'm not sure that it can be determined which is "more plausible" than the other.

Unholy mother of Hell, you really are all over the place, aren't you ?

 

[Bri]

No, it's not. Let's assume that flognorps exist and that they cause babies to be born with red hair. Can you use the frequency of red haired babies as information about the probability that flognorps exist?

Yup, if you assume certain probabilities of red-haired babies if flognorps exist and without flognorps, and you assume a certain probability that flognorps exist without considering red-haired babies, you can argue the probability that flognorps exist considering that red-haired babies exist.

Only because someone decided to assign that characteristic to the idea of God.

Yes, it does makes certain assumptions in the premise about the nature of the god to presume that a fine-tuned universe would be more likely if a god exists than without. Again, you can feel free to reject that premise if you like.

You didn't answer my question.

The answer is that your scenario doesn't apply (it's the equivalent of assuming multiple universes), and even if it did you're just rejecting the premise (the multiple universes objection is a rejection of the premise).

It's the difference between observing the characteristics of something and assigning a characteristic to something that we have not observed.

As far as I know, there is no evidence that we have observed extra-terrestrial intelligent life.

I wasn't talking about extra-terrestrial intelligent life. I was talking about the life we have observed.

Ironically, in using our planet's circumstances that gave rise to intelligent life as the model to extrapolate the probability of of extra-terrestrial intelligent life (as with Drake's equation), we are assigning characteristics to unobserved extra-terrestrial life.

If your point is that Drake's equation uses observed data to try to estimate values for some of the terms, so does the argument cj posted (estimates of fine-tuning are based on observed data).

I may be misunderstanding what you mean by "constrained" but neither seems to be "more constrained" than the other by any meaningful definition of "constrained."

You agreed earlier that some value were more likely than others. That is an example of "constrained".

It might be helpful if you actually defined it rather than specifying an example. Does it mean that some value assigned to some probability of some term of the argument is more likely than another value that might be assigned to the same term? If so, some values are probably more likely than others in both cases, so they are both "constrained" by that definition. But I don't know what you mean by "more constrained" in this context. How do you calculate the amount of "constrainment?"

I think if you rid yourself of the idea that someone is trying to draw a line between irrational and rational, it would help to make this clearer.

I think that's entirely what the discussion is about. But the same problems arise even if you just want to say that one is "more rational" than the other.

-Bri

 

[articulett]

I think the universe is much more "finely tuned" for single celled organisms myself.

It looks pretty much like multicellular creatures evolved because they could... not because of some grand plan. Where were the dinosaurs in this plan one wonders?

 

[fls]

Yup, if you assume a certain (higher) probability of red-haired babies if flognorps exist than without flognorps, and you assume a certain probability that flognorps exist without considering red-haired babies, you can argue the probability that flognorps exist considering that red-haired babies exist.

And...ummm...that doesn't bother you?

Yes, it certainly makes certain assumptions in the premise about the nature of the god to presume that a fine-tuned universe would be more likely if a god exists than without. Again, you can feel free to reject that premise if you like.

I'm perfectly happy accepting the premise. However, when discussing "if A then B", it's not logically coherent to say "B therefore A".

The answer is that your scenario doesn't apply, and even if it did you're just rejecting the premise.

My scenario did not require a multi-verse. All it did was give you an example of an unlikely event (such as a fine-tuned universe), and a thing that, if present, made the event more likely. According to you, this means that I've also made the thing more likely. How do you reconcile that with the knowledge that the thing is entirely made up?

It might be helpful if you actually defined it rather than specifying an example. Does it mean that some value assigned to some probability of some term of the argument is more likely than another value that might be assigned to the same term? If so, some values are probably more likely than others in both cases, so they are both "constrained" by that definition. But I don't know what you mean by "more constrained" in this context. How do you calculate the amount of "constrainment?"

The probability of intelligent alien life is constrained by the fraction of planets able to support life per planetary system. So if the fraction is small, then smaller numbers of intelligent alien civilizations are more likely that larger numbers. This makes no difference to God, so all values are still equally likely.

I think that's entirely what the discussion is about. But the same problems arise even if you just want to say that one is "more rational" than the other.

-Bri

Can't you just say one is more plausible than the other?

Linda

 

[Belz...]

Yup, if you assume certain probabilities of red-haired babies if flognorps exist and without flognorps, and you assume a certain probability that flognorps exist without considering red-haired babies, you can argue the probability that flognorps exist considering that red-haired babies exist.

 

[Belz...]

Where were the dinosaurs in this plan one wonders?

The plan er... works in mysterious ways.

 

[Belz...]

Anyway... top answer the OP. Yes, yes they can. Everybody can be rational, but everybody has one or more blind spots.

As I've said before, we each have our woo.

 

[Bri]

And...ummm...that doesn't bother you?

I didn't say that I agreed with the premise of the argument. That said, if God (capital "G") is the creator of the universe, it might make more sense that the universe is fine-tuned for human habitation than flognorps causing red-haired babies.

I'm perfectly happy accepting the premise. However, when discussing "if A then B", it's not logically coherent to say "B therefore A".

I understand what you're saying and I understand that it looks that way, but it's a valid Bayesian analysis and it's not saying "if A then B, B, therefore A." It's assigning a probability to B based on A and without A, assigning a probability for A without regard to B, then saying that if B is true, a certain probability for A can be concluded.

My scenario did not require a multi-verse. All it did was give you an example of an unlikely event (such as a fine-tuned universe), and a thing that, if present, made the event more likely. According to you, this means that I've also made the thing more likely. How do you reconcile that with the knowledge that the thing is entirely made up?

I'm just saying that your scenario isn't equivalent to the argument cj posted. Here's your scenario:

I'm looking for a disease to name after myself, so I declare that Linda's Syndrome is a condition which leads to a sodium measurement of 118. Out of hundreds of sodium measurements, only a handful will have a measurement of 118. Considering that Linda's Syndrome does not actually exist, does someone with a sodium measurement of 118 make it possible that my idea is true?​

First of all, it is possible that there is a condition that changes people's sodium levels to 118 (the probability is greater than 0).

But rereading it now, I don't think the problem is that it's equivalent to assuming multiple universes. It seems like you may be misinterpreting what is meant by "rare." Having a small number of 118's out of hundreds is exactly what you would expect to see, so that scenario isn't rare at all. Having 99 out of 100 showing a 118 sodium level would be rare.

In other words, if you were to assign actual probabilities from your description, the chances of a handful of people out of hundreds having sodium levels of 118 with the existence of L.S. and without the existence of L.S. would be relatively close (in fact, with L.S. it seems like you might have more people with sodium levels of 118). Therefore, the conclusion would be that the probability of the existence of L.S. would be very low (way less than 50%).

This one better mirrors the argument in question:

There is a 1 in a million chance that a sodium-changing virus exists that would cause a population of 10,000 people to all have the same sodium level.

Assume that if a sodium-changing virus exists, there is a 99% probability that all of the population would have the same sodium level. Assume that if a sodium-changing virus doesn't exist, there is a .0[bajillion zeros here]1% probability that all of the population would have the same sodium level.

There are 10,000 residents of the Island of Fishead. You have them all tested for sodium. All of them have sodium levels of 118.

We can conclude a high probability that a sodium-changing virus exists.

The probability of intelligent alien life is constrained by the fraction of planets able to support life per planetary system. So if the fraction is small, then smaller numbers of intelligent alien civilizations are more likely that larger numbers. This makes no difference to God, so all values are still equally likely.

Incorrect. If the universe isn't fine-tuned (according to the argument) then there is a much higher likelihood that a god exists than if the universe isn't fine-tuned.

Can't you just say one is more plausible than the other?

One isn't necessarily more plausible than the other according to RandFan's definition of "plausible." You can certainly say that you believe one to be more plausible than the other or are of the opinion that one is more plausible than the other. But I don't think you'd get the same answer as to which is more plausible from everyone you ask.

-Bri

 

[JoeTheJuggler]

There is life on earth. The probability is 1.

More accurately, since we know by life on earth that life exists, the probability of life existing on other Earth-like planets is greater than zero.

Bri, you mentioned that the only things that have a probability of zero are those that are impossible because they are internally, logically inconsistent.

CJ is an Anglican (according to his sig). I just checked, and Anglicans believe that 3 things can be 1 and 1 thing can be three. This is part of their definition of God. Yet, it's impossible exactly the same way a 4 sided triangle is impossible. Yet people believe in this God.

So what do you make of this belief?

If this is the definition of God in the argument cj posted, you would reject the premise because the probability of such a God is zero.

Again, this is why I wish theists would be upfront about what they believe. The Trinity is a very specific, and logically impossible, concept of God. Funny you don't see this God making an appearance in "proofs" of the existence of God.

 

[JoeTheJuggler]

I won't argue the point since it's off-topic and I don't necessarily disagree.

So why did you bring it up?

Could it be because this is the sort of "reasoning" that led to the argument cj posted? It does sound like the sort of thing that might lead someone to think the probability of a life-containing universe is higher if God exists. (And then use that as a premise to "prove" that God probably exists--yep circular reasoning.)