Can theists be rational?

[fls]

I don't want to speak for Ivor, but I think he was saying that if the input values aren't well-supported by evidence, you will not necessarily get a valid conclusion. That's true of all equations, including Drake's. In practice, Bayes theorem is used in many applications where the input values are well-supported by evidence. Where the evidence is sketchy, the conclusion may not be valid.

See the courtroom example in this article for a "fuzzier" approach to the use of Bayes theorem to add up evidence against a defendant to try to determine whether the defendant is guilty. The accuracy of the result would depend on how certain you are of the probabilities placed on each piece of evidence against the defendant.

-Bri

That's my point. Bayes' theorem is used where the input values are supported by evidence. Even your courtroom example has a very well-defined likelihood ratio. So why use it, instead of other forms of reasoning, when it can't give you valid results? Does anyone besides Religious Apologists claim that this obviously useless exercise is a useful exercise?

Linda

 

[Bri]

And that's the point. I think Bri is confusing logically possible and hypothetically possible with theoretical (theoretically possible).

The reason I asked you to define it when you first used the phrase is because "theoretically possible" usually does mean "hypothetically possible." You seem to mean it as "according to a known theory." yy2bggggs did a pretty good job explaining that known theory isn't necessarily complete, and is occasionally changed as new information is learned.

In this case, there is no reason to assume that a supernatural being cannot exist, and being super-natural wouldn't be bound by the laws governing our universe.

In the case of a fine-tuner, such a being would probably have to be outside of the natural laws in order to be able to fine-tune the constants that are part of the natural laws -- in other words such a being would be responsible for defining the natural laws and would not be bound by them.

To be theoretical the proposition must be amenable to theory and that theory must take into account the mechanisms for doing whatever it does.

A fine-tuner would be amenable to theory, just not known theory.

-Bri

 

[RandFan]

The reason I asked you to define it when you first used the phrase is because "theoretically possible" usually does mean "hypothetically possible."

Not by anyone who knows the definitions of the words.

You seem to mean it as "according to a known theory."

No. Only that we can construct a valid theory that is not contrary to the laws of physics.

In this case, there is no reason to assume that a supernatural being cannot exist, and being super-natural wouldn't be bound by the laws governing our universe.

The superman conjecture. This is that mental shortcut I was talking about. Simply put in a get out of jail free card and everything is possible. It works for comic books but it isn't a basis for rational belief.

That's what you are missing.

No supernatural-unexplainable-yellow-sun-superman-theory is needed to posit ET intelligent life. Intelligent life outside of our solar system IS theoretical. God ISN'T.

Now do you see the difference?

In the case of a fine-tuner, such a being would probably have to be outside of the natural laws in order to be able to fine-tune the constants that are part of the natural laws -- in other words such a being would be responsible for defining the natural laws and would not be bound by them.

Yes, isn't that convenient. "Oh, I can't give you a theory because it is outside of the laws of physics." You've just eliminated any rational basis to assume it is real.

A fine-tuner would be amenable to theory...

If we toss the known loss of physics and posit unknown forces and laws then yes.

...just not known theory.

So would Superman and Spiderman and the Fantastic Four. Here's the question, is it rational to believe in any of them? Is it rational to go looking for them?

• We have a theoretical basis for ET intelligent life.
• We have no theoretical basis for a "Fine-tuner". In fact we have to posit supernatural laws that are contrary to all known laws of physics.

THAT is why one is rational and the other isn't.

 

[Bri]

So why bother using Bayes' theorem, in this situation, when you can't get valid results? Can you give me an example of any other situation where Bayes' theorem is used even though the results won't be useful?

Why are you singling out Bayes theorem when this is true of ANY equation?

We know that if Joe lives 3 miles from us and arrived at our house in 3 minutes, and the speed limit is 40, Joe was speeding:

speed = distance / time
speed = 3 / 3 minutes
speed = 1 mile per minute = 60 mph

But that's only true if we know that all the information is accurate. If we're not sure how long it took Joe to get to us (or we're not really sure the distance is 3 miles), we're not sure whether Joe was speeding.

We can form a logical argument out of this by assuming as a premise that the distance is 3 miles and the time is 3 minutes, and conclude that Joe was speeding. But the conclusion is only valid if the premise is valid. ANY logical argument requires acceptance of the premises in order to accept the conclusion. The better the evidence, the more you can be certain of the result. If there is conclusive evidence to support the premise, you might be compelled to agree with the conclusion. But even if you don't know the distance is exactly 3 miles, you can still draw a reasonable conclusion that Joe was speeding as long as you know it was approximately 3 miles and that Joe got there in approximately 3 minutes.

In other words, how "useful" the equation is depends on how certain you are of the premise, which depends on the amount and quality of evidence to support it.

An argument for aliens based on Drake's equation and the fine-tuning argument based on Bayes theorem both depend on variables for which there is no conclusive evidence.

-Bri

 

[Malerin]

Yes, let's take your argument to its natural conclusion.

The odds of you existing are
1 in 600,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000.

We are not talking what "could" happen by tossing coins. We are talking what DID happen.

My existence is only a significant result to me. It's like HTTHTHTTHHTHTHTHTHHTHHTHTHTHTHHTHTHTHTHTHTH. 100 heads in a row or the alphabet lottery OTOH, is a significant result for anybody observing it.

 

[RandFan]

An argument for aliens based on Drake's equation and the fine-tuning argument based on Bayes theorem both depend on variables for which there is no conclusive evidence.

• One requires an appeal to unknown forces and rules that are contrary to all known laws of physics.
• The other doesn't.

 

[fls]

Why are you singling out Bayes theorem when this is true of ANY equation?

Because it was the theorem used in the fine-tuning argument.

Would you consider this a valid* use of Bayes' theorem? And if so, can you give an example of the same use of Bayes' theorem in a different field of inquiry (in a way that is accepted as valid within that field).

Linda

*speaking mostly of external validity, although internal validity has been shown to have been relevant in this thread, as well

 

[RandFan]

My existence is only a significant result to me.

If this improbable event is not in and of itself significant then why should any improbable event be significant when we have no other basis to find significance (like conscious intent)?

*Conscious intent + improbability = significance.

Improbability = ?

*We know for a fact that there is potential for conscious intent to be an explanation when a human being is flipping a coin or human beings construct the machines that render the lottery numbers.

 

[Bri]

Not by anyone who knows the definitions of the words.

Webster doesn't know the definitions of the words?

the·o·ret·i·cal

1 a: relating to or having the character of theory : abstract b: confined to theory or speculation often in contrast to practical applications : speculative <theoretical physics>
2: given to or skilled in theorizing <a brilliant theoretical physicist>
3: existing only in theory : hypothetical <gave as an example a theoretical situation>​

No. Only that we can construct a valid theory that is not contrary to the laws of physics.

The laws of physics are based on our observation of the natural universe. The notion of a supernatural being does not violate the laws of physics, which pertain to natural beings and not necessarily to supernatural beings.

Now do you see the difference?

No, I really don't, and I'm not just being contrary. I don't understand the distinction you're trying to make.

We don't know whether the existence of aliens fits within known theory since known theory doesn't tell us the events and circumstances by which intelligent life emerged here, and therefore known theory cannot tell us the probability that the events and circumstances by which intelligent life emerged on this planet happened elsewhere. Just like known theory doesn't tell us whether or not there's a teapot orbiting Jupiter even though teapots certainly fit within known theory.

Yes, isn't that convenient. "Oh, I can't give you a theory because it is outside of the laws of physics." You've just eliminated any rational basis to assume it is real.

Not by any definition of "rational" I can think of (without resorting to special pleading).

If we toss the known loss of physics and posit unknown forces and laws then yes.

No need to toss the known laws of physics. Clearly the laws of physics pertain to the natural universe, not necessarily to the supernatural.

So would Superman and Spiderman and the Fantastic Four. Here's the question, is it rational to believe in any of them? Is it rational to go looking for them?

I would say about as rational as looking for aliens or teapots orbiting Jupiter. There is about as much evidence for all of those things.

• We have a theoretical basis for ET intelligent life.
• We have no theoretical basis for a "Fine-tuner". In fact we have to posit supernatural laws that are contrary to all known laws of physics.

THAT is why one is rational and the other isn't.

I'm still unclear as to what you mean by "theoretical basis" here.

-Bri

 

[Bri]

Because it was the theorem used in the fine-tuning argument.

Again, this is true of any equation used in any logical argument, including Drake's equation. I'm trying to understand why you're singling out the equation used in a fine-tuning argument.

Would you consider this a valid* use of Bayes' theorem? And if so, can you give an example of the same use of Bayes' theorem in a different field of inquiry (in a way that is accepted as valid within that field).

Like all equations used in logical arguments, it's as valid as the premises. I referenced the example related to court cases, and also provided a simple example in my previous post. Yes, it's reasonable to conclude that Joe was probably speeding if you accept that the premise is reasonable (that Joe was approximately 3 miles away, that Joe got there in approximately 3 minutes, and that the speed limit was approximately 40).

-Bri

 

[Bri]

• One requires an appeal to unknown forces and rules that are contrary to all known laws of physics.
• The other doesn't.

Neither are inconsistent with the known laws of physics.

-Bri

 

[GStan]

Neither are inconsistent with the known laws of physics.

-Bri

If it is not bound by the known laws of physics, it is inconsistent with the known laws of physics.

 

[Paulhoff]

In this case, there is no reason to assume that a supernatural being cannot exist, and being super-natural wouldn't be bound by the laws governing our universe.

Or magic, Harry Potter etc, except that the super-natural doesn't prove anything, can't be used for anything, can't be put to anything of use, except if you what to use it for a power-base of some kind, and/or just to lazy to read real information that has so far been learned about the universe, that can be used.

Paul

 

[fls]

Again, this is true of any equation used in any logical argument, including Drake's equation. I'm trying to understand why you're singling out the equation used in a fine-tuning argument.

Because the fine-tuning argument is the argument under discussion as a supposedly rational argument for theism. Is it rational to use Bayes' theorem under conditions where it can not give you valid results?

Like all equations used in logical arguments, it's as valid as the premises.

Right. And under these conditions, valid premises are not available.

I referenced the example related to court cases, and also provided a simple example in my previous post.

Yes, you provided examples where valid premises were available. I'm looking for examples where valid premises are not available, yet the use of Bayes' theorem is still considered uncontroversial.

Linda

 

[Ivor the Engineer]

The problem of understanding why a run of N heads, where N is a number greater than, say, 10, would reasonably make someone suspicious the coin which produced the sequence was not fair can be explained by humans semi-consciously using Bayesian reasoning.

When reasoning about the fairness of a coin given some observed sequence of heads and tails generated by it, we estimate the posterior probabilities for various hypotheses given the observed sequence. Possible hypotheses we rapidly consider include: fair coin; biased heads coin; biased tails coin; alternating heads-tails coin, etc. The hypothesis we select is the one we estimate has the highest probability of generating the sequence from the set of hypotheses we have considered.

What we should of course do next is calculate the ratio between the likelihood of our chosen hypothesis and the likelihood of the other hypotheses to get an idea of how much better our hypothesis explains the data compared to the alternative hypotheses, but for some reason we have a tendency to hone in very quickly on a particularly hypothesis and disregard alternatives, often not even considering them in the first place.

 

[Bri]

If it is not bound by the known laws of physics, it is inconsistent with the known laws of physics.

Even if you want to pretend that the natural universe is defined by the laws of physics and not the other way around, a being that can adjust the constants of the universe controls the laws of physics and is not governed by them.

Such a being is not inconsistent with the known laws of physics, which relate only to the natural universe.

-Bri

 

[Belz...]

Says the average human being

Ah, so it's an opinion, then.

whose ability to see patterns is the result of many millions of years of evolution.

I think you're making my point for me, here. The ability to imagine patterns doesn't make those patterns true. Or significant, for that matter.

If you were to see someone tossing coins and he threw 30 heads in a row that the only possible explanations were magical genies or pure chance?

All else being equal, yes. I keep repeating those words and you seem to miss them.

People can cheat.

No, really ? Who's been cheating about the physical laws ?

Amazed and suspicious have to come from surprised.

Okay. Touché.

If you were to win the lottery playing 123456 I would indeed find it suspicious.

Why ? Why wouldn't you find it suspicious if I won playing 12-19-47-30-31-22 ? You're making 1-2-3-4-5-6 more significant than it should.

In short, what you're seemingly doing is expecting that, since there is, say 1 in 14 billion chances of us getting that sequence, it would take 14 million tries to get it. But that's quite a ridiculous opinion.

Indeed, if 123456 came up in the lottery I'd be suspicious even if nobody won.

That makes even less sense.

 

[Bri]

Or magic, Harry Potter etc, except that the super-natural doesn't prove anything, can't be used for anything, can't be put to anything of use, except if you what to use it for a power-base of some kind, and/or just to lazy to read real information that has so far been learned about the universe, that can be used.

If your point is that we don't know of the existence of anything beyond the natural and therefore the supernatural can't be used to explain anything, I agree. The same can be true of aliens or teapots orbiting Jupiter though. I don't mind defining any belief for which there is no conclusive evidence irrational as long as you're consistent.

-Bri

 

[Belz...]

The notion of a supernatural being does not violate the laws of physics, which pertain to natural beings and not necessarily to supernatural beings.

In other words, the notion of a supernatural being violates the laws of physics.

 

[Bri]

Because the fine-tuning argument is the argument under discussion as a supposedly rational argument for theism. Is it rational to use Bayes' theorem under conditions where it can not give you valid results?

Again, the question must be is it rational to use ANY EQUATION under conditions where it cannot give valid results. Why the special pleading here?

Right. And under these conditions, valid premises are not available.

That depends what you consider "valid." In the example of whether or not Joe is speeding, it depends on how sure you are of the premises. If I'm pretty sure that Joe was approximately 3 miles away, I can be pretty sure of the results. If Joe could have been 1 mile away, the conclusion isn't as valid since it's possible that Joe wasn't speeding.

Yes, you provided examples where valid premises were available. I'm looking for examples where valid premises are not available, yet the use of Bayes' theorem is still considered uncontroversial.

These are all examples where the validity of the premises is subjective. Any time the premises of an argument are subjective but reasonable, the results will be "controversial" -- meaning that reasonable people can disagree. This occurs when there is a lack of conclusive evidence upon which to base the premise. It's not unreasonable to conclude that Joe was speeding, but that doesn't mean that someone would necessarily be irrational if they concluded otherwise.

-Bri