I'm struggling to see a point to this thread. Other than putting the usual and now apparently obligatory boot into Dawkins.

the mouse wrote:

Thommo wrote:

It's an entirely different situation. It would be like reasoning that because you believe I do not have a pet dragon that you do not believe I have a pet cat. Can you see the difference?

The only difference here, is that one is a dragon and the other is a cat.

Is it your position, that a lack of evidence for Tom's pet dragon is a valid reason to assume that it likely does not exist?

...but a lack of evidence for Tom's pet cat, would not be sufficient to assume it's non-existence?

Yes.

Can you see the difference?

Thommo wrote:

the mouse wrote:

Thommo wrote:

It's an entirely different situation. It would be like reasoning that because you believe I do not have a pet dragon that you do not believe I have a pet cat. Can you see the difference?

The only difference here, is that one is a dragon and the other is a cat.

Is it your position, that a lack of evidence for Tom's pet dragon is a valid reason to assume that it likely does not exist?

...but a lack of evidence for Tom's pet cat, would not be sufficient to assume it's non-existence?

Yes.

Can you see the difference?

No. Please explain why the rule applies to one but not the other?

Because we know that both cats and cat owners exist. You can in the real world observe people who have cats in their home as pets.

If you simply applied basic background knowledge, such as that there are cats living as pets in about 20% of UK homes it is readily apparent that reasoning that since you simply don't know if I own a cat therefore I don't own a cat you will be wrong very frequently (about 20% of the time if you make this guess about everyone in the same situation). Making the same guess about dragons will not result in you being wrong.

Thommo wrote:Because we know that both cats and cat owners exist. You can in the real world observe people who have cats in their home as pets.

If you simply applied basic background knowledge, such as that there are cats living as pets in about 20% of UK homes it is readily apparent that reasoning that since you simply don't know if I own a cat therefore I don't own a cat you will be wrong very frequently (about 20% of the time if you make this guess about everyone in the same situation). Making the same guess about dragons will not result in you being wrong.

I like probabilities.

Let's assume we're talking about a less frequently owned pet, like a snake. We'll assume that .01% of the UK population owns a snake.

There in no evidence that Tom owns a snake. Can we assume by this lack of evidence that Tom likely doesn't have a snake?

Especially considering the likelihood of any random person not owning a snake is 99.99%.

Unlike a cat, the likelihood of a guess that he doesn't have one, is extremely likely to be true.

Would a lack of evidence allow us to assume that Tom is very unlikely to own a snake?

We don't have a lack of evidence that Tom is unlikely to own a snake, you've described a situation in which we know the probability is 0.01% - incidentally, you might be surprised to find out how popular snakes are as pets these days http://www.telegraph.co.uk/earth/350088 ... -dogs.html , I was and thought that was quite interesting.

The point is that without knowing the animal exists in the first place there is no basis on which to assign a non-zero probability. You can have a philosophical debate about whether or not one is entitled to say in such situations that the thing in question doesn't exist (e.g. Santa, Dragons, Unicorns, Elves etc.) or must remain completely agnostic, although in reality nobody actually does this, you don't get arguments over whether it's legitimate to say that bugs bunny does not exist. This is by the by though - whatever you decide it doesn't generalise to objects which are known to exist.

Thommo wrote:We don't have a lack of evidence that Tom is unlikely to own a snake

No, we have no evidence that he has a snake, but you seem to suggest that unlike God or Dragons, we can't assume based on this lack of evidence that he's unlikely to have one. Though I would think if the likelihood of any random person owning a snack was a very low, than it's safe to assume that Tom likely does not have a snake.

you've described a situation in which we know the probability is 0.01%
- incidentally, you might be surprised to find out how popular snakes are as pets these days http://www.telegraph.co.uk/earth/350088 ... -dogs.html , I was and thought that was quite interesting.

Well it doesn't have to be snake but any pet for which the probability of owning one is close to .01%. I'm just using snakes here with an assumed probability, for arguments sake.

The point is that without knowing the animal exists in the first place there is no basis on which to assign a non-zero probability..

But we're not talking about knowing something exists, but rather the probability of it's existence. What's the probability that the universe was created by some being? Is it 0%? The probability that we're just a part of some computer simulation? 0%?

In fact we're not even talking about the existence of snakes, as much as the "existence" of a pet snake, owned by Tom.

quisquose wrote;
It always amuses me to hear theists take a dig at NSS and mention the number of members like it means anything. The witch Cristina Odone famously said "the National Secular Society boasts about 7,000 members – the same number as the British Sausages Appreciation Society".

The Apathy League has trouble attracting members too. Perhaps that means there are very few apathetic people?

It might be interesting to find out I suppose, if anyone could be bothered.

the mouse wrote:

Thommo wrote:We don't have a lack of evidence that Tom is unlikely to own a snake

No, we have no evidence that he has a snake, but you seem to suggest that unlike God or Dragons, we can't assume based on this lack of evidence that he's unlikely to have one.

This is incorrect, you told me that the probability was 0.01%, you can't then say you have no evidence - you're contradicting yourself.

the mouse wrote:But we're not talking about knowing something exists, but rather the probability of it's existence. What's the probability that the universe was created by some being? Is it 0%? The probability that we're just a part of some computer simulation? 0%?

There's no defined sample space, you can't assign a probability.

the mouse wrote:In fact we're not even talking about the existence of snakes, as much as the "existence" of a pet snake, owned by Tom.

But the fact that snakes and snake owners exist is highly relevant, it allows us to form a sample space and discuss probability (e.g. the number of snake owners as a proportion of the number of people).

lyingcheat wrote:The Apathy League has trouble attracting members too. Perhaps that means there are very few apathetic people?

It might be interesting to find out I suppose, if anyone could be bothered.

On the other hand world apathy day was a roaring success - nobody turned up.

lyingcheat wrote:The Apathy League has trouble attracting members too. Perhaps that means there are very few apathetic people?

It might be interesting to find out I suppose, if anyone could be bothered.

Strangely, the apathy league members themselves can be quite enthused about having others sharing their apathy.

the mouse wrote:Though I would think if the likelihood of any random person owning a snack was a very low, than it's safe to assume that Tom likely does not have a snake.

I have a snack several times a week, and I always own them first. (...but what has that got to do with whether or not Tom has a snake?)

Nebogipfel wrote: To coin a phrase, all that is necessary for evil to triumph is for good men to do nothing.

(My bold.)



Strange; I could've sworn I'd heard it before.

Remember when you used the time machine to visit today?

quas wrote:Remember when you used the time machine to visit today?

I'm my own time machine; since being born, I have traveled more than 60 years into the future.

Thommo wrote:

This is incorrect, you told me that the probability was 0.01%, you can't then say you have no evidence - you're contradicting yourself.

No, I said the probability of any random person owning a snake is .01%, and that there is no evidence for Tom having a pet snake. If this probability is evidence for Tom owning one, than the probability of any random person being gay (let's say 10%), is evidence that you're gay.

the mouse wrote:

There's no defined sample space, you can't assign a probability. [...]the fact that snakes and snake owners exist is highly relevant, it allows us to form a sample space and discuss probability (e.g. the number of snake owners as a proportion of the number of people)

Who said it's not a defined space? If what makes the snake example a defined space, that allows us to assign probability to Tom's snake ownership, is the existence of snakes. Than why can't the existence of things being created, allows us to assign probability to the likelihood of something being created?

Does our existence allow us to assign a likelihood to the existence of life on other planets?

redwhine wrote:

Nebogipfel wrote: To coin a phrase, all that is necessary for evil to triumph is for good men to do nothing.

(My bold.)



Strange; I could've sworn I'd heard it before.

It doesn't mean "to make a new phrase", but the opposite.

the mouse wrote:

Thommo wrote:

This is incorrect, you told me that the probability was 0.01%, you can't then say you have no evidence - you're contradicting yourself.

No, I said the probability of any random person owning a snake is .01%, and that there is no evidence for Tom having a pet snake. If this probability is evidence for Tom owning one, than the probability of any random person being gay (let's say 10%), is evidence that you're gay.

Yes, it's just not decisive evidence. It's certainly enough that it makes it plausible if I say "I'm gay", in a way that it is not plausible if I claim "I can fly by flapping my arms".

Tom is "a random person" as you've described him, what you're doing is self-contradicting.

the mouse wrote:

the mouse wrote:

There's no defined sample space, you can't assign a probability. [...]the fact that snakes and snake owners exist is highly relevant, it allows us to form a sample space and discuss probability (e.g. the number of snake owners as a proportion of the number of people)

Who said it's not a defined space?

Ok, provide the definition then.

the mouse wrote:Does our existence allow us to assign a likelihood to the existence of life on other planets?

Sample size of one? Not really, no.

Thommo wrote:

Tom is "a random person" as you've described him, what you're doing is self-contradicting.

I never said Tom was a random person, in fact Tom in my example was a stand in for Paul, who is no more a random person than you. I do think we've gotten ourselves into an issue over semantics, regarding the terms "evidence" and "random". If you're saying that the percentage of homosexuals in any given population, constitutes as evidence (though not decisive) that you Thommo might be gay, that's fine, though we might have a slightly different meaning of the term "evidence" that we are using here.

It appears to me, that "evidence" is the what creates the probability even if it's a low probability like .01%. And the reason why we can't apply probabilities to God/s and Dragons is because there is no evidence for them, at least according to you?

Yet, you do seem to believe that even though we don't have any direct evidence of Tom owning a snake, such as pictures of him with one, statements from him, or his friends confirming or alluding to him having one, we can still use indirect evidence (though not decisive) such as the likelihood of any random person owning a pet, to confer some level of likelihood that Tom owns a snake?

Is this a correct assessment of your views here?

Sample size of one? Not really, no.

Let's clarify here. We know that life on planets is possible, given that we know life exists on earth. But you don't think it's reasonable to assume that life on other planets is a possibility based on this? You believe that the existence of life on earth, doesn't increase the likelihood of life existing on other planets?

(I'm wondering if this divergence from the original OP can be branched off into a new thread by one of the mods)

the mouse wrote:

Thommo wrote:

Tom is "a random person" as you've described him, what you're doing is self-contradicting.

I never said Tom was a random person, in fact Tom in my example was a stand in for Paul, who is no more a random person than you. I do think we've gotten ourselves into an issue over semantics, regarding the terms "evidence" and "random". If you're saying that the percentage of homosexuals in any given population, constitutes as evidence (though not decisive) that you Thommo might be gay, that's fine, though we might have a slightly different meaning of the term "evidence" that we are using here.

It appears to me, that "evidence" is the what creates the probability even if it's a low probability like .01%. And the reason why we can't apply probabilities to God/s and Dragons is because there is no evidence for them, at least according to you?

If evidence creates the probability then you can't have a probability without evidence and you're still mired in self-contradiction.

the mouse wrote:Yet, you do seem to believe that even though we don't have any direct evidence of Tom owning a snake, such as pictures of him with one, statements from him, or his friends confirming or alluding to him having one, we can still use indirect evidence (though not decisive) such as the likelihood of any random person owning a pet, to confer some level of likelihood that Tom owns a snake?

Is this a correct assessment of your views here?

Assuming by likelihood you mean probability (there's a technical difference that I doubt is important here, but we should probably stay aware of it), then yes the fact that there are people who own snakes is relevant to whether or not some particular person who has no defining characteristics (i.e. is random in the way you used it above) might own a snake.

the mouse wrote:

Sample size of one? Not really, no.

Let's clarify here. We know that life on planets is possible, given that we know life exists on earth. But you don't think it's reasonable to assume that life on other planets is a possibility based on this? You believe that the existence of life on earth, doesn't increase the likelihood of life existing on other planets?

You asked about likelihood, not possibility. There's no meaningful way to ascribe a probability*, there's a possibility.

the mouse wrote:(I'm wondering if this divergence from the original OP can be branched off into a new thread by one of the mods)

That's a good idea!

* Because our sample size is 1, someone mentioned recently this exact thing in another thread and tried to use a Maximum Likelihood estimation technique, but that's utterly invalid as it's going to come up with weird quirks like estimating the probability of another planet with life being the same as the probability of another planet with human life - small sample size for ML techniques being regarded as something less than 50 to 100.

The central limit theorem doesn't hold for small sample sizes either, so the poisson distribution at sample size 1 looks nothing like a normal distribution.