Can theists be rational?

[Bri]

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'.

I'm not sure what insects and hominids have to do with anything, so please explain. Whereas size is obviously going to affect the probability of something having gone unnoticed in a limited area, invisibility would not. So why is invisibility a more "unlikely" characteristic (and more unlikely than what)?

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

What do you mean by "similar conditions lead to similar outcomes?" What similar conditions are you referring to?

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

Consider it ignored!

Drake's equation can allow one to draw conclusions about the direction of the result.

Not in my opinion. We have no idea what fraction of planets will go on to develop life (much less intelligent life). So beyond it being greater than 0% and less than 100% we're not left with much "direction" to go on.

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.

No, that's not the case. With Bayes theorem, the new evidence can be either for or against the hypothesis and can therefore raise or lower the prior probability. With the argument in question, if you were to for example assume in the premise a lower priority of the universe supporting life if a god exists, the result would be the opposite. If you were to assume that the universe isn't fine-tuned at all, it would neither raise nor lower the prior probability of a god.

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.

The results aren't dependent on how the argument is set up. The results are entirely dependent on the premises. The argument itself is directly based off of Bayes theorem, in this form:

                P(E|H)P(H)
P(H|E) = -------------------------
         P(E|H)P(H) + P(E|~H)P(~H)

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

Sure, OK!

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

Then we are in agreement.

Is this just a matter of semantics?

You're arguing my point. If it's not based on evidence, it's based on faith.

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.

If you don't think the universe is fine-tuned, you would disagree with the premises. Specifically, you might think that life would be just as probable with a god as without one (which would leave the probability of a god at 1 in a million, or highly improbable). The point here is that you haven't successfully attacked the argument at all, you've only attacked the premises of the argument. The argument itself (which is really just Bayes theorem) is sound.

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.

Not really. In fact, remember that the direction it starts out with is stacked against the existence of a god (the premises actually consider the prior probability of a god 1 in a million, or highly improbable). If the universe isn't fine-tuned, the conclusion remains the same (probably no god). Even if the universe is only "slightly" fine-tuned (that there is only a relatively slightly higher probability of the universe supporting life with a god) the conclusion would be no god. So, no, the equation isn't designed to produce a high probability of god. It only produces a high probability of god if you accept the premises.

-Bri

 

[fls]

I'm not sure what insects and hominids have to do with anything, so please explain. Whereas size is obviously going to affect the probability of something having gone unnoticed in a limited area, invisibility would not. So why is invisibility a more "unlikely" characteristic (and more unlikely than what)?

There are normal reasons for why we don't notice something - it is small, we haven't been there to look. We haven't yet encountered 'invisible', but we have encountered new things in places we haven't been to before. That there can be things at other locations isn't really an "undiscovered quality" like "invisible" would be.

What do you mean by "similar conditions lead to similar outcomes?" What similar conditions are you referring to?

The conditions leading to intelligent life.

Not in my opinion. We have no idea what fraction of planets will go on to develop life (much less intelligent life). So beyond it being greater than 0% and less than 100% we're not left with much "direction" to go on.

What I meant is that if we did know what fraction of planets will go on to develop life, it can change the number up or down.

No, that's not the case. With Bayes theorem, the new evidence can be either for or against the hypothesis and can therefore raise or lower the prior probability.

The posterior probability can only be lower than the prior probability if you assume that physical constants fine-tuned for life are less likely when god is present than when god is absent.

With the argument in question, if you were to for example assume in the premise a lower priority of the universe supporting life if a god exists, the result would be the opposite.

Right (if you mean to say the same thing that I just said above). However, that is the premise that has been avoided in all these discussions. The purpose of the argument is to propose a fine-tuner that makes life more likely, rather than less likely in its presence, in order to provide support for the idea of a fine-tuner.

The results aren't dependent on how the argument is set up. The results are entirely dependent on the premises.

I'm not saying something different from that. I'm saying that no matter how you vary or argue over the extent to which there is fine-tuning, the prior probability of life, or the prior probability of God, whether or not the posterior probability is higher than the prior is entirely dependent upon whether or not you set it up so that life is more likely in the presence of God than in its absence. Everything after that is relative.

You're arguing my point. If it's not based on evidence, it's based on faith.

Then it is a semantic argument. I'm saying that not all information is 'evidence'.

If you don't think the universe is fine-tuned, you would disagree with the premises. Specifically, you might think that life would be just as probable with a god as without one (which would leave the probability of a god at 1 in a million, or highly improbable). The point here is that you haven't successfully attacked the argument at all, you've only attacked the premises of the argument. The argument itself (which is really just Bayes theorem) is sound.

What I'm trying to get at is that the conclusions (as stated in this thread) that are purportedly the result of the argument, are not the conclusions that can be drawn from this use of Bayes' theorem. Regardless of whether or not we agree with the premises, the conclusions as stated are not valid. The use of Bayes' theorem is sound (sorta), it's the conclusions that are not because they contain the premise.

Not really. In fact, remember that the direction it starts out with is stacked against the existence of a god (the premises actually consider the prior probability of a god 1 in a million, or highly improbable). If the universe isn't fine-tuned, the conclusion remains the same (probably no god). Even if the universe is only "slightly" fine-tuned (that there is only a relatively slightly higher probability of the universe supporting life with a god) the conclusion would be no god. So, no, the equation isn't designed to produce a high probability of god. It only produces a high probability of god if you accept the premises.

-Bri

I agree. The equation is designed to produce a higher probability of God, rather than a high probability of God, at least some of the time, anyway. However, conclusions are also being drawn from that higher probability, even if the probability isn't 'high' (whatever that means). And nobody set it up in a way that a lower probability of God could be produced - i.e. it is only allowed to vary in one direction.

Linda

 

[Malerin]

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.

Of course, the police do this all the time. If they come across a body that was stabbed by a left-handed person with type-A blood on it that, their theory will be the murderer was left-handed and has type-A blood. Are you saying that theories should NOT be proposed to account for the evidence? There is a danger of proposing a theory ad-hoc, but that's not going on in the FT argument.

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, my belief is based on Bri's email (which I believe him to be truthful about), different professors I've had, and the various invalid attempts to attack Bayes itself. And also in the same way that I know 2+2=4 and
2+2 /= 5.

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).

If that were all I was doing, I would get confirmation if there was evidence for fine-tuning or not (Pr(E) could have any value and there would still be confirmation). Obviously, this is not true. No evidence for fine-tuning = no confirmation for a fine-tuner.

 

[Malerin]

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!

Not if we find out the multiverse is based on some fundamental principle and spits out (or is composed of) 99.9999999% lifeless universes. Then you would be back to the question Why is there something instead of nothing?, which isn't a very good argument for God or fine-tuners.

 

[fls]

Of course, the police do this all the time. If they come across a body that was stabbed by a left-handed person with type-A blood on it that, their theory will be the murderer was left-handed and has type-A blood. Are you saying that theories should NOT be proposed to account for the evidence? There is a danger of proposing a theory ad-hoc, but that's not going on in the FT argument.

I'm afraid that an idea which doesn't contribute a necessary or sufficient explanation and makes no useful predictions, but serves only to 'explain' a single event after the fact, is the very defintion of proposing a 'theory' ad-hoc.

If that were all I was doing, I would get confirmation if there was evidence for fine-tuning or not (Pr(E) could have any value and there would still be confirmation). Obviously, this is not true. No evidence for fine-tuning = no confirmation for a fine-tuner.

The way you've set it up, any value for p(E) will give you confirmation (i.e. the posterior probability for a fine-tuner will increase).

Linda

 

[Malerin]

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.

P(H/E) is a proposition. It makes a claim about the world ((H), which is either true or false), which is assigned an epistemic value based on some evidence (E). In subjective probability, whatever number P(H/E) has is your degree of belief in whether a hypothesis is true or false, based on some evidence. If H= circles have four sides and E= the coin landed heads, then Pr(H/E) = 0 and will always = 0, given that hypothesis because it is making a claim about reality that we know is false. Doesn't matter what E is. If H= all triangles have 180 degrees and E= the sun rose today, P(H/E) will = 1 and will always = 1 because Pr(H) = 1. If H= Mr. Simpson is a murderer and E = his blood was found all over the crime scence, Pr(H/E) will be very high, which is to say (subjectively) that I believe it is very likely true that Mr.Simpson is a murderer because his blood was found all over the scene. We have a proposition, and also a reason why that proposition is considered more likely true or false. Pr(H/E) then becomes the new Pr(H) and E becomes a part of the set of background knowledge.

 

[Bri]

There are normal reasons for why we don't notice something - it is small, we haven't been there to look. We haven't yet encountered 'invisible', but we have encountered new things in places we haven't been to before. That there can be things at other locations isn't really an "undiscovered quality" like "invisible" would be.

Air and certain other substances are typically invisible. Can you clarify?

The conditions leading to intelligent life.

Supernatural seems less likely than conditions leading to intelligent life? How are you judging the likelihood of either one? I don't think you can judge one thing of which we have no idea more or less likely than another of which we have no idea.

The posterior probability can only be lower than the prior probability if you assume that physical constants fine-tuned for life are less likely when god is present than when god is absent.

Yes, true. If you assume they are the same, the posterior probability will be a low probability that a god exists (1 in a million).

Right (if you mean to say the same thing that I just said above). However, that is the premise that has been avoided in all these discussions. The purpose of the argument is to propose a fine-tuner that makes life more likely, rather than less likely in its presence, in order to provide support for the idea of a fine-tuner.

Again, you're objecting to the premises, not to the argument itself. You can assume the opposite and thereby lower the prior probability of the existence of a god (as you said yourself above). Even if you assume that the two values are the same (as would be the case if there is no fine-tuning) the result would be a 1 in a million probability of a god (not likely).

Then it is a semantic argument. I'm saying that not all information is 'evidence'.

True, invalid information isn't "evidence" but also wouldn't be something upon which to base a belief. So can you give me an example of some information that you feel would allow someone to rationally believe in the existence of extra terrestrial intelligent life that isn't evidence?

What I'm trying to get at is that the conclusions (as stated in this thread) that are purportedly the result of the argument, are not the conclusions that can be drawn from this use of Bayes' theorem. Regardless of whether or not we agree with the premises, the conclusions as stated are not valid.

I'll have to disagree with you here. If we agree on the premise, the conclusion as stated is not only accurate, but is indeed valid.

The use of Bayes' theorem is sound (sorta), it's the conclusions that are not because they contain the premise.

Sorta? If you don't accept Bayes theorem (which has been in use since the mid-1700's) then I'm not sure how I can convince you except to say that if it was only "sorta" sound someone smarter than I would probably have noticed by now!

Assuming that Baye's theorem is, in fact, sound (and it is, in fact, sound), then indeed the conclusion is valid if the premise is valid.

I agree. The equation is designed to produce a higher probability of God, rather than a high probability of God, at least some of the time, anyway. However, conclusions are also being drawn from that higher probability, even if the probability isn't 'high' (whatever that means). And nobody set it up in a way that a lower probability of God could be produced - i.e. it is only allowed to vary in one direction.

As you pointed out yourself above, that is simply incorrect:

The posterior probability can only be lower than the prior probability if you assume that physical constants fine-tuned for life are less likely when god is present than when god is absent.​

It can vary the other direction if you accepted a premise that the probability of life in the universe is less with a god than without one.

-Bri

 

[Malerin]

I'm afraid that an idea which doesn't contribute a necessary or sufficient explanation and makes no useful predictions, but serves only to 'explain' a single event after the fact, is the very defintion of proposing a 'theory' ad-hoc.



The way you've set it up, any value for p(E) will give you confirmation (i.e. the posterior probability for a fine-tuner will increase).

Linda

Certainly not. If I claim H (something made the universe) = .5, Pr(E/H) = .5 and Pr(E) = .9, not only is there no confirmation, there's disconfirmation.
Pr(H/E) drops to .27.

 

[fls]

Air and certain other substances are typically invisible. Can you clarify?

Would you expect an elephant to be entirely gaseous? I think it matters how far away (and I don't mean physical distance) something would be from our own experience.

Supernatural seems less likely than conditions leading to intelligent life? How are you judging the likelihood of either one? I don't think you can judge one thing of which we have no idea more or less likely than another of which we have no idea.

We have no idea of intelligent life? Gee, thanks a lot.

Again, you're objecting to the premises, not to the argument itself.

I'm objecting not to the premise. I'm objecting to the inclusion of the premise in the conclusion.

True, invalid information isn't "evidence" but also wouldn't be something upon which to base a belief. So can you give me an example of some information that you feel would allow someone to rationally believe in the existence of extra terrestrial intelligent life that isn't evidence?

I think that you are calling all observation, evidence (particularly those that are gathered carefully and systematically). Is that right? I am simply distinguishing between observations that help to prove something right or wrong from observations that support an idea or serve to stimulate a hypothesis.

I'll have to disagree with you here. If we agree on the premise, the conclusion as stated is not only accurate, but is indeed valid.

Well, then how about valid, but trivial. This is the conclusion that Malerin has wrenched from the argument.

"If I assume that the posterior probability will increase, then the posterior probability increases."

Sorta? If you don't accept Bayes theorem (which has been in use since the mid-1700's) then I'm not sure how I can convince you except to say that if it was only "sorta" sound someone smarter than I would probably have noticed by now!

The "sorta" is because attempting to form an argument without any constraining information is fairly fruitless, even taking into consideration efforts to give it a superficial patina of validity by invoking a 'Theorem' (unless of course it involves a lot of beer and your best buds).

Assuming that Baye's theorem is, in fact, sound (and it is, in fact, sound), then indeed the conclusion is valid if the premise is valid.

Okay. Valid and utterly trivial.

As you pointed out yourself above, that is simply incorrect:

The posterior probability can only be lower than the prior probability if you assume that physical constants fine-tuned for life are less likely when god is present than when god is absent.​

It can vary the other direction if you accepted a premise that the probability of life in the universe is less with a god than without one.

-Bri

Has anyone who is using the fine-tuning argument in support of God asked us to consider that premise?

Linda

 

[fls]

Certainly not. If I claim H (something made the universe) = .5, Pr(E/H) = .5 and Pr(E) = .9, not only is there no confirmation, there's disconfirmation.
Pr(H/E) drops to .27.

Because your scenario is impossible. It invokes negative probabilities.

Linda

 

[Malerin]

Because your scenario is impossible. It invokes negative probabilities.

Linda

Yeah, I was a little sloppy on Pr(E). I don't think H can be disconfirmed, but it certainly can be confirmed or stay the same, depending on the value of the evidence:

Pr(H/E) = Pr(E/H) x Pr(H) / (Pr(E/H) x Pr(H) + (Pr(E/~H) x Pr(~H)

(H)= something made the universe
Pr(E/H) = .5 (Given that something made the universe, I don't know that I would expect life or not).
Pr(E/~H) = .5 (Given that something didn't make the universe, I still wouldn't be surprised that life exists. Maybe theres a multiverse of infinite universes or the universe is cyclical or life can adapt to whatever environment).

Pr(H/E) = .5. No confirmation

However, if I think it very surprsing that life exists given that something didn't make the universe
(PR(E/~H) <<.5)), then Pr(H/E) will be confirmed.

So it's not true that H is confirmed no matter what. But you're right: I was wrong that it was disconfirmed.

Edit: You can still get disconfirmation if you think Pr(E/H) < Pr(E/~H). For example, I might not know what to expect about life given a universe creator (Pr(E/H) = .5)), while at the same time I find the existence of life totally expected because I have a strong belief that there are an infinite number of universes (Pr(E/~H) = .99)). In that case, you get significant disconfirmation:

.25 / .745

Pr(H/E) drops from .5 to .33 because the multiverse is a better explainer of life than a universe creator.

 

[fls]

So it's not true that H is confirmed no matter what. But you're right: I was wrong that it was disconfirmed.

Edit: You can still get disconfirmation if you think Pr(E/H) < Pr(E/~H). For example, I might not know what to expect about life given a universe creator (Pr(E/H) = .5)), while at the same time I find the existence of life totally expected because I have a strong belief that there are an infinite number of universes (Pr(E/~H) = .99)). In that case, you get significant disconfirmation:

.25 / .745

Pr(H/E) drops from .5 to .33 because the multiverse is a better explainer of life than a universe creator.

I didn't say H was confirmed no matter what. I said H was confirmed, no matter what, whenever you hypothesize that life is more likely in the presence of god than in the absence of god. The opposite is also true. H is disconfirmed, no matter what, if you hypothesize that life is less likely in the presence of god than in the absence of god (as you did above).

Linda

 

[Bri]

Would you expect an elephant to be entirely gaseous? I think it matters how far away (and I don't mean physical distance) something would be from our own experience.

Invisible elephants are just like regular elephants (except invisible) and therefore are not "far away" at all. Aliens, on the other hand, might be very different than we are. So are you saying it's more rational to believe in invisible elephants?

We have no idea of intelligent life? Gee, thanks a lot.

Please re-read what I wrote. I was referring to the conditions leading to intelligent life, not intelligent life itself.

I'm objecting not to the premise. I'm objecting to the inclusion of the premise in the conclusion.

I'm sorry, but the objection you were making to which I replied is a rejection of the premises, specifically that it is more likely that life would exist with a god than without one (rather than the other way around).

In no way does the argument include the premise in the conclusion. In fact, the argument is an extremely straightforward application of Bayes theorem.

I think that you are calling all observation, evidence (particularly those that are gathered carefully and systematically). Is that right? I am simply distinguishing between observations that help to prove something right or wrong from observations that support an idea or serve to stimulate a hypothesis.

I still don't see the distinction you're making. Observations that serve to "stimulate a hypothesis" (whatever that means -- do you mean stimulate a discussion about a hypothesis?) but don't go towards proving the hypothesis would not be considered evidence of the hypothesis.

So again, a belief in a hypothesis without evidence is a faith-based belief.

Are you saying that Drake's equation is such an "observation?" An equation such as Drake's equation isn't exactly an observation either, any more than Bayes theorem is an observation. Are you saying that such "observations" (if you can call them that) would be valid reasons for believing the hypothesis to be true?

Well, then how about valid, but trivial. This is the conclusion that Malerin has wrenched from the argument.

Explain what you mean by "trivial" here. Bayes theorem doesn't assume that the prior probability will increase, nor does the argument cj posted (which essentially just plugs numbers directly into Bayes theorem).

Has anyone who is using the fine-tuning argument in support of God asked us to consider that premise?

Has anyone who is arguing that intelligent aliens exist asked us to consider a premise that concludes that intelligent aliens don't exist? Why would someone ask you to consider a premise that they disagree with and that leads to a conclusion that is opposite of the one they're arguing for?

-Bri

 

[fls]

Invisible elephants are just like regular elephants (except invisible) and therefore are not "far away" at all. Aliens, on the other hand, might be very different than we are. So are you saying it's more rational to believe in invisible elephants?

They can't be just like regular elephants, except invisible, since invisibility would require dramatic alterations in multiple characteristics.

Please re-read what I wrote. I was referring to the conditions leading to intelligent life, not intelligent life itself.

Well, we also have some experience of the conditions leading to intelligent life.

I'm sorry, but the objection you were making to which I replied is a rejection of the premises, specifically that it is more likely that life would exist with a god than without one (rather than the other way around).

I'm not necessarily objecting to the premise, I'm just pointing out that we don't have any independent confirmation of that premise, and so the conclusion simply represents the premise.

In no way does the argument include the premise in the conclusion. In fact, the argument is an extremely straightforward application of Bayes theorem.

Then where is your independent confirmation of the premise that life is more likely in the presence of god than in its absence?

I still don't see the distinction you're making. Observations that serve to "stimulate a hypothesis" (whatever that means -- do you mean stimulate a discussion about a hypothesis?) but don't go towards proving the hypothesis would not be considered evidence of the hypothesis.

Right. If I hypothesize that aspirin will help prevent strokes based on my observation that those patients I have that are taking aspirin have not had any strokes, while some of my patients not taking aspirin have, it will encourage me to perform a clinical trial in order to gather evidence that my hypothesis is true.

So again, a belief in a hypothesis without evidence is a faith-based belief.

But my aspirin hypothesis is better supported by my observations than my hypothesis that smearing poop on my face will prevent strokes, even if I never do a clinical trial.

Are you saying that Drake's equation is such an "observation?" An equation such as Drake's equation isn't exactly an observation either, any more than Bayes theorem is an observation. Are you saying that such "observations" (if you can call them that) would be valid reasons for believing the hypothesis to be true?

I'm just saying that they provide support for the idea.

Explain what you mean by "trivial" here. Bayes theorem doesn't assume that the prior probability will increase, nor does the argument cj posted (which essentially just plugs numbers directly into Bayes theorem).

That's exactly what is assumed as soon as you assume that life is more likely in the presence of god than in its absence. Both Malerin and cj made that assumption.

Has anyone who is arguing that intelligent aliens exist asked us to consider a premise that concludes that intelligent aliens don't exist? Why would someone ask you to consider a premise that they disagree with and that leads to a conclusion that is opposite of the one they're arguing for?

-Bri

The difference is that the assumptions in Drake's equation don't force the result in a particular direction. But that particular assumption in Bayes' theorem means that whatever else you do, you will always get an answer with a higher probability than you started with.

Linda

 

[Bri]

They can't be just like regular elephants, except invisible, since invisibility would require dramatic alterations in multiple characteristics.

I get where you're trying to go with this, but I doubt that you're going to be able to quantify something like that in any meaningful way that would allow you to state that one is "farther away" than the other.

Well, we also have some experience of the conditions leading to intelligent life.

We really don't know what conditions and/or events lead to the emergence of intelligent life. We don't know the likelihood that there is intelligent life elsewhere in the universe.

I'm not necessarily objecting to the premise, I'm just pointing out that we don't have any independent confirmation of that premise, and so the conclusion simply represents the premise.

What do you mean by "represents the premise?" If you mean that the conclusion follows from the premise, that's true of any valid argument. It's also true of the argument for the existence of extra terrestrial intelligent life that the conclusion follows from the premises, some of which we have no independent confirmation of.

Then where is your independent confirmation of the premise that life is more likely in the presence of god than in its absence?

Where is your independent confirmation that it is likely that a significant number of planets other than our own will develop life, much less intelligent life?

Right. If I hypothesize that aspirin will help prevent strokes based on my observation that those patients I have that are taking aspirin have not had any strokes, while some of my patients not taking aspirin have, it will encourage me to perform a clinical trial in order to gather evidence that my hypothesis is true.

The fine-tuned universe argument has encouraged further research to try to find out if the universe is indeed fine-tuned.

But my aspirin hypothesis is better supported by my observations than my hypothesis that smearing poop on my face will prevent strokes, even if I never do a clinical trial.

The fine-tuned universe hypothesis is also better supported by observation than your hypothesis that smearing poop on your face will prevent strokes.

I'm just saying that they provide support for the idea.

No they don't. They don't provide support for or against the idea. They are simply tools for thinking about the idea.

That's exactly what is assumed as soon as you assume that life is more likely in the presence of god than in its absence. Both Malerin and cj made that assumption.

It sounds like you're confusing the argument and its premises with an equation used by the argument. Neither Bayes theorem nor Drake's equation assume anything about the conclusion. They are not arguments in and of themselves. To form an argument from either one, you would need premises in the form of values plugged into terms of the equation. Given these values, a particular result will follow.

So just as the argument for a god cj posted (based on Bayes theorem) assumes a premises in order to obtain a conclusion, an argument for aliens based on Drake's equation must assume a premise in order to obtain a conclusion. Give either one different premises, and they can conclude the opposite.

The difference is that the assumptions in Drake's equation don't force the result in a particular direction.

You're correct that Drake's equation doesn't force the results in a particular direction, just as Bayes theorem doesn't force the results in a particular direction. But the premises of an argument for the existence of intelligent aliens based on Drake's equation certainly do, just as the premises of the argument for the existence of a god based on Bayes theorem do.

But that particular assumption in Bayes' theorem means that whatever else you do, you will always get an answer with a higher probability than you started with.

That particular argument using Bayes theorem is an argument for the existence of a god, and the conclusion indeed follows from the premises. Similarly, an argument for the existence of aliens using Drake's equation would follow from the premises.

-Bri

 

[fls]

I get where you're trying to go with this, but I doubt that you're going to be able to quantify something like that in any meaningful way that would allow you to state that one is "farther away" than the other.

Right, I cannot prevent you from disagreeing.

We really don't know what conditions and/or events lead to the emergence of intelligent life. We don't know the likelihood that there is intelligent life elsewhere in the universe.

Right, like most areas of exploration, we start with pushing the edges of what we do know.

What do you mean by "represents the premise?"

I mean that it contains the premise, it's saying the same thing twice, it's circular, etc.

If you mean that the conclusion follows from the premise, that's true of any valid argument.

I mean that the conclusion is a restatement of the premise.

Where is your independent confirmation that it is likely that a significant number of planets other than our own will develop life, much less intelligent life?

Our observations of the universe.

The fine-tuned universe hypothesis is also better supported by observation than your hypothesis that smearing poop on your face will prevent strokes.

Right. I'm not referring to that part of the argument.

No they don't. They don't provide support for or against the idea. They are simply tools for thinking about the idea.

I don't care what label you want to use. "Tools" is fine with me.

It sounds like you're confusing the argument and its premises with an equation used by the argument. Neither Bayes theorem nor Drake's equation assume anything about the conclusion. They are not arguments in and of themselves. To form an argument from either one, you would need premises in the form of values plugged into terms of the equation. Given these values, a particular result will follow.

So just as the argument for a god cj posted (based on Bayes theorem) assumes a premises in order to obtain a conclusion, an argument for aliens based on Drake's equation must assume a premise in order to obtain a conclusion. Give either one different premises, and they can conclude the opposite.

You're correct that Drake's equation doesn't force the results in a particular direction, just as Bayes theorem doesn't force the results in a particular direction. But the premises of an argument for the existence of intelligent aliens based on Drake's equation certainly do, just as the premises of the argument for the existence of a god based on Bayes theorem do.

That particular argument using Bayes theorem is an argument for the existence of a god, and the conclusion indeed follows from the premises. Similarly, an argument for the existence of aliens using Drake's equation would follow from the premises.

-Bri

Before I go any further...do you understand that if one assumes that life is more likely in the presence of god than it is in its absence, that no matter what else you propose (a fine-tuned universe, a non-fine-tuned universe, a high probability of God, a low probability of God), the posterior probability will be higher than the prior probability?

Linda

 

[articulett]

I get where you're trying to go with this, but I doubt that you're going to be able to quantify something like that in any meaningful way that would allow you to state that one is "farther away" than the other.
-Bri

I think Linda and others have already made valid arguments as to why one is way more "far away" than the other.

I think it would be more accurate to state that no amount of evidence will get you to see the validity of these arguments.

 

[Bri]

Right, I cannot prevent you from disagreeing.

Right. Also, I can come up with counter-examples, such as a teapot orbiting Jupiter. It's exactly the same as a teapot here on earth, except its location. I don't think that lends any more credence to its existence than anything else.

Right, like most areas of exploration, we start with pushing the edges of what we do know.

That still doesn't make the proposition anything other a belief without evidence.

I mean that it contains the premise, it's saying the same thing twice, it's circular, etc.

...

I mean that the conclusion is a restatement of the premise.

No more than the conclusion of an argument based on Drake's equation is a restatement of the premise.

Where is your independent confirmation that it is likely that a significant number of planets other than our own will develop life, much less intelligent life?

Our observations of the universe.

Which observations, specifically? There are no observations that lead to that conclusion, which makes it a belief without evidence.

Before I go any further...do you understand that if one assumes that life is more likely in the presence of god than it is in its absence, that no matter what else you propose (a fine-tuned universe, a non-fine-tuned universe, a high probability of God, a low probability of God), the posterior probability will be higher than the prior probability?

Yes, of course. And you understand that if you assume the opposite, the posterior probability will be lower than the prior probability? And you understand that if you assume in the premise that they are the same, the prior and posterior probabilities will be the same?

-Bri

 

[articulett]

Oh the energy it takes to blind oneself so that one may continue to believe the unbelievable.

 

[fls]

Right. Also, I can come up with counter-examples, such as a teapot orbiting Jupiter. It's exactly the same as a teapot here on earth, except its location. I don't think that lends any more credence to its existence than anything else.

Thank you for proving my point.

That still doesn't make the proposition anything other a belief without evidence.

I mentioned previously that evidence isn't the only kind of information that is useful to us.

No more than the conclusion of an argument based on Drake's equation is a restatement of the premise.

It's quite different. I'll explain below.

Which observations, specifically? There are no observations that lead to that conclusion, which makes it a belief without evidence.

I mentioned previously that evidence isn't the only kind of information available to us.

Yes, of course. And you understand that if you assume the opposite, the posterior probability will be lower than the prior probability? And you understand that if you assume in the premise that they are the same, the prior and posterior probabilities will be the same?

-Bri

Okay. Here's the problem. Earlier you stated this:

It sounds like you're confusing the argument and its premises with an equation used by the argument. Neither Bayes theorem nor Drake's equation assume anything about the conclusion. They are not arguments in and of themselves. To form an argument from either one, you would need premises in the form of values plugged into terms of the equation. Given these values, a particular result will follow.

And you specifically stated that the new evidence to be used for the argument for God (i.e. the value to be plugged in) is evidence that the universe is fine-tuned - that is, the probability that the physical constants necessary to lead to life would have the value that they have due to chance. Unfortunately, once you have agreed that life is more likely by some amount in the presence of God than its absence, it no longer matters whatsoever what the probability is that the universe is fine-tuned for life. Likelihood ratios are not influenced by the base rate. There is no need (or place) to "plug" this value into the equation, because it no longer can influence the outcome.

On the other hand, every value of the Drake equation, when plugged into the terms of the equation, will influence the result.

So my question is, how can the presence of fine-tuning be evidence of God if the posterior probability of God is unchanged regardless of whether these physical constants are common or rare?

Linda