Logic: Can you disprove a univeral negative?

[ceedre]

Is it possible to disprove a universal negative? (I just got done listening to the Craig Zindler Debate of 1993, and I’m not sure who I agree with.)
Example:

1. Someone makes a claim that there is a polka dotted duck.
   Is this possible to disprove? It would seem that it is not, since we cannot prove that polka dotted ducks do not exist on other planets.
2. Someone makes a claim that there is a God.
   Again, impossible to disprove.

The answer to this question seems to decide if atheists need to prove that God does not exist. Zindler claims that atheists do not need to prove that God does not exist, because it is impossible to do so. Craig claims that atheists need to prove that God does not exist, because that is what they claim. He also says that you can disprove a universal negative, but I’m not sure how.

I suppose the question really is: Who has the burden of proof? The atheist to prove that God doesn’t exist or the theist to prove that God exists?

For an atheist to be right, Craig says that he needs to prove that God does not exist. Zindler says that he needs to show that belief in God is simply unreasonable.

 

[ateista]

Example:

1. Someone makes a claim that there is a polka dotted duck.
   Is this possible to disprove? It would seem that it is not, since we cannot prove that polka dotted ducks do not exist on other planets.
2. Someone makes a claim that there is a God.
   Again, impossible to disprove.

What about the claim that an “Invisible Pink Unicorn” does not exist?

At a glance one can easily prove that the “Invisible Pink Unicorn” does not exist. After all “invisible” and “pink” cannot be reconciled. But what do the unicornists say to that? They say that it is the mystery of the Unicorn, not subject to rational scrutiny. One must accept it on faith that the Unicorn is both invisible and pink and there is no problem.

Impasse.

The anti-unicornists say that there never was an actual sighting or any physical evidence for the Unicorn and thus the existence of the Unicorn cannot be taken seriously. The unicornists counter this by pointing out that the Unicorn exists out of time and space.

Impasse again.

Now comes the real problem. The unicornists assert that the Unicorn issued some commandments in which it described the correct Absolute Morality by which one must lead his life. Furthermore they demand that those commandments be reflected by the secular laws, and everyone should adhere to them.

And this is the point when the anti-unicornists stand up and say “Whoa”. They start to demand evidence for the Unicorn. They have no problem with the unicornists beliefs as long as they do not wish to impose their views on others. But the unicornists are adamant. They say that the anti-unicorninsts want to impose their disbelief on them, by removing the Unicorn from the schools, by enacting laws which are clear violations of the Unicorn’s commandments.

And the merry-go-round just keeps spinning…

The question is: should any claim be given serious consideration? No matter how outlandish the claim is?

The only possible answer is: “NO”. If someone wants to assert the existence of anything, and wishes to be taken seriously, then he MUST present evidence for his claims.

To demand that the disbelievers must present “proof” for the nonexistence of the Unicorn is a feeble attempt to avoid the conclusion: the claims of the Unicornists are nonsensical.

 

[jrabs]

No - but I do wonderfully with double negatives.
Now those little buggers I have down pat.

 

[john_doran]

Is it possible to disprove a universal negative? (I just got done listening to the Craig Zindler Debate of 1993, and I’m not sure who I agree with.)
Example:

1. Someone makes a claim that there is a polka dotted duck.
   Is this possible to disprove? It would seem that it is not, since we cannot prove that polka dotted ducks do not exist on other planets.

i think you’re asking if it is possible to prove a universal negative…

for one thing, the proposition “there is a polka-dotted duck” is not a universal negative proposition. but the proposition “there are no polka-dotted ducks” is; you are asking if it is possible to prove the latter.

and whether or not it’s possible to prove something like that depends on what counts as a “proof”. for example, imagine we knew the complete duck genome, and know that it contains no instructions for polka-dotted pigments, and cannot be changed to include such instructions in one or two generations. would that be enough of a proof? or would we have to rule out the possibility that someone engineered a polka-dotted duck somewhere, that we don’t know of? or that no one has painted polka-dots on a duck?

more generally, i would ask why it is suggested that universal negative propositions aren’t capable of proof.

i mean, isn’t the proposition “there are no provable universal negatives” itself a universal negative?

ceedre:

1. Someone makes a claim that there is a God.
   Again, impossible to disprove.

maybe, maybe not. but, as per the above, why is it that the proposition “god does not exist” is said to be unprovable?

for one thing, it is not a universal negative, but rather a singular negative, so even if universal negatives are proof-resistant, that would be irrelevant in this case.

ceedre:

I suppose the question really is: Who has the burden of proof? The atheist to prove that God doesn’t exist or the theist to prove that God exists?

For an atheist to be right, Craig says that he needs to prove that God does not exist. Zindler says that he needs to show that belief in God is simply unreasonable.

anyone making an affirmation needs to support that affirmation.

whether or not the atheist needs to support his position depends on what his central claim happens to be: if it is “god does not exist”, then the atheist needs to present evidence that god does not exist; if it’s “belief in god is unreasonable”, then evidence of that claim needs to be presented.

but it is not enough to support the proposition “god does not exist” with evidence of the proposition “belief in god is unreasonable”, since the two claims are wildly divergent.

 

[john_doran]

To demand that the disbelievers must present “proof” for the nonexistence of the Unicorn is a feeble attempt to avoid the conclusion: the claims of the Unicornists are nonsensical.

do you need to prove that claim? or do you just get a free pass on everything you say?

look, the rhetoric of your post notwithstanding, anyone believing ~p needs to prove ~p.

in the case of atheism, for example, if ~p is “the concept of god is nonsensical” then proof of that claim is going to have to be provided.

at the very least, you’re going to have to demonstrate the nature and extent of the “atheist epistemic dispensation” upon which you are otherwise relying.

 

[ateista]

look, the rhetoric of your post notwithstanding, anyone believing ~p needs to prove ~p.

But the atheist does not say “I believe that God does not exist”, he says: “I do not believe that God exists”. It is not a positive belief, it is a lack of belief.

in the case of atheism, for example, if ~p is “the concept of god is nonsensical” then proof of that claim is going to have to be provided.

That is true. The problem is that the “concept of God” varies from person to person, and it is insufficiently defined. Even for Catholicism, which is much more robust than other religions are, I have yet to see a coherent definition.

Let me give a few generic points. The definition of anything should have the following properties if that definition is to be taken seriously.

1. The definition must not have words, phrases which are meaningless.
2. The definition’s words, phrases cannot be logically contradictory.
3. The corollaries of the definition cannot contradict our existing knowledge.

If any of these criteria is violated, the definition is nonsensical. Can we agree at least on these requirements?

 

[john_doran]

But the atheist does not say “I believe that God does not exist”, he says: “I do not believe that God exists”. It is not a positive belief, it is a lack of belief.

fair enough. but that’s the traditional definition of agnostic, not atheist.

ateista:

Let me give a few generic points. The definition of anything should have the following properties if that definition is to be taken seriously.

1. The definition must not have words, phrases which are meaningless.
2. The definition’s words, phrases cannot be logically contradictory.
3. The corollaries of the definition cannot contradict our existing knowledge.

If any of these criteria is violated, the definition is nonsensical. Can we agree at least on these requirements?

sure. with the following caveats:

1. much will hinge on what counts as “meaningless”;
2. i agree, but would observe that logical contradictoriness is simply a way of being meaningless;
3. depends on which of the conflicting corollary and our existing knowledge possesses the greater warrant. almost all of what you are calling our existing knowledge is simply provisional, and cannot be granted pride of epistemic place simply because it’s what we believe now.

 

[ateista]

fair enough. but that’s the traditional definition of agnostic, not atheist.

I really don’t want to go into semantics, but “agnostic” is an epistemological term, while “theist” and “atheist” are metaphysical ones. Technically we are all “agnostics” because we do not know if God exists or not. Huxley coined the term “agnostic” and it is used as a middle gound, which is unjustified. One either **has a belief **in God’s existence (theist) or **lacks the belief **(atheist). If anyone would know, the belief would be useless.

sure. with the following caveats:

1. much will hinge on what counts as “meaningless”;

Agreed. This might prove the most difficult part, to find a mutually acceptable “meaning” for some terms. (Just an example, which might be a point of contention, would be “existence” outside space and time.)

1. i agree, but would observe that logical contradictoriness is simply a way of being meaningless;

In a sense. Two separately meaningful terms: “married” and “bachelor” become contradictory when joined together.

1. depends on which of the conflicting corollary and our existing knowledge possesses the greater warrant. almost all of what you are calling our existing knowledge is simply provisional, and cannot be granted pride of epistemic place simply because it’s what we believe now.

A huge part, yes. But not everything. The explanation of gravity is provisional (though well established), the existence of gravity is not. The non-existence of ether (as a carrying medium for light) is proven via the Michaleson-Morley experiments.

---

There is something which would be good agree upon, because otherwise a meaningful discussion is impossible. In the past I experienced problems, because the theist used God, or some of God’s attibutes as “axioms”, while the atheist used these terms as “hypotheses”.

To the point: when talking about the “goodness” of God, the theist says: “because God is good (axiom), whatever we percieve as “bad” is simply a misinterpretation, or due to the lack of our knowledge” - in other words: “measurement error”. The atheist says: whatever we perceive as “bad” is bad, unless a suitable explanation comes around. The atheist is willing to hypothesize that God is good, but if the evidence does not support it, the hypothesis is to be discarded. For me as an atheist the proposition: “God is good” is not an axiom, it is merely a hypothesis.

Can we agree on this approach?

 

[john_doran]

I really don’t want to go into semantics, but “agnostic” is an epistemological term, while “theist” and “atheist” are metaphysical ones. Technically we are all “agnostics” because we do not know if God exists or not. Huxley coined the term “agnostic” and it is used as a middle gound, which is unjustified. One either **has a belief **in God’s existence (theist) or **lacks the belief **(atheist).

they’re all epistemological terms, since they all describe belief-states.

ateista:

If anyone would know, the belief would be useless.

not true: knowledge is just belief of a certain kind. some say “justified and true”, others, “formed under the right conditions”, and so on…

but whatever - for you, “atheist” means "lacking belief in god(s)’. we’ll just go with that.

ateista:

A huge part, yes. But not everything. The explanation of gravity is provisional (though well established), the existence of gravity is not.

not quite - the only thing that we can really take for granted is that things behave in certain ways in certain situations. calling that behaviour “gravity” already makes some thing responsible for those behaviours.

i agree that we have very good reason to believe that there actually is some thing that is universally responsible for the effects we attribute to “gravity” - i’m just pointing out that anything more than the phenomenology of our experience of certain behaviours is something about which to be less certain.

ateista:

The non-existence of ether (as a carrying medium for light) is proven via the Michaleson-Morley experiments.

the michelson-morley experiments proved no such thing…

lorentzian relativity, for example, is a fully articulated relativistic theory that assumes the ether.

and einstein didn’t disprove it, either: he simply assumed it didn’t exist as a part of his belief in the philosophy of ernst mach.

now, there may very well be no such thing as the ether, but we’ve done nothing to demonstrate that there isn’t.

ateista:

There is something which would be good agree upon, because otherwise a meaningful discussion is impossible. In the past I experienced problems, because the theist used God, or some of God’s attibutes as “axioms”, while the atheist used these terms as “hypotheses”.

To the point: when talking about the “goodness” of God, the theist says: “because God is good (axiom), whatever we percieve as “bad” is simply a misinterpretation, or due to the lack of our knowledge” - in other words: “measurement error”. The atheist says: whatever we perceive as “bad” is bad, unless a suitable explanation comes around. The atheist is willing to hypothesize that God is good, but if the evidence does not support it, the hypothesis is to be discarded. For me as an atheist the proposition: “God is good” is not an axiom, it is merely a hypothesis.

Can we agree on this approach?

i doubt it: you’re asking me to agree to your axiom, “what you think is bad, is bad, unless it can be ‘suitably’ explained (to you)as good (or, presumably, at least as not bad)”, but then ask me to lay aside the putative theist axiom “god is good”. why should i agree to do that?

 

[Verbum_Caro]

Two separately meaningful terms: “married” and “bachelor” become contradictory when joined together.

Not that John needs my help (and not that what I am about to post* is* helpful) but. . .

your example of two meaningful words joined together are not necessarily contradictory. For instance I can say: “Smith was a bachelor and now is married.” I can say “Our bachelor Smith is now married!” Both words describe the same subject (Smith).

Or I could say “Smith is a bachelor, but is married in the online world of Second Life.”

Or I can say “Smith is a bachelor, but married to his work.”

Or I can say that “Smith is married, but behaves as a bachelor.” If your point was concerning conjoining the two words together directly I could make a stronger pejorative statement about Smith and say “Smith is a married bachelor.”

The point being that even in mundane conversation we sometimes use words which would be contradictory if they were predicated of the subject “at the same time in the same aspect.” Theological language is even more precise and the “time” and “under which aspect” often needs to be explicitly stated.

Just my :twocents:.
VC

 

[ateista]

i doubt it: you’re asking me to agree to your axiom, “what you think is bad, is bad, unless it can be ‘suitably’ explained (to you)as good (or, presumably, at least as not bad)”, but then ask me to lay aside the putative theist axiom “god is good”. why should i agree to do that?

Oh, well. That pretty much settles it. I use the “duck principle” - and of course the “proof of the pudding”.

I would assume that you use the same principles in your life. That is why it is an axiom. You do not keep testing the concept that “putting your hand into a fire - hurts” again and again.

The existence of God is only a hypothesis, therefore God’s goodness cannot be more than just another hypothesis.

 

[john_doran]

Oh, well. That pretty much settles it. I use the “duck principle” - and of course the “proof of the pudding”.

sure - and you’d need to support that as the proper epistemic principle to use…

ateista:

I would assume that you use the same principles in your life. That is why it is an axiom. You do not keep testing the concept that “putting your hand into a fire - hurts” again and again.

look, i simply refused to accept your axiom: i don’t accept anything like “bad is what i say it is unless you can satisfy me i’m wrong”, as true, let alone axiomatic, and nor should i (a fortiori, i don’t live my life by anything remotely like such a “principle”).

you want a proposition like that to enter the conversation, then you’re going to have to demonstrate its validity.

let’s call that the “what’s good for the goose” principle.

ateista:

The existence of God is only a hypothesis, therefore God’s goodness cannot be more than just another hypothesis.

maybe, maybe not. but i don’t insist on “god is good” as an axiom - i just object to being made to reject what might have been an axiom of mine, while being made to accept an axiom of yours.

 

[ateista]

look, i simply refused to accept your axiom: i don’t accept anything like “bad is what i say it is unless you can satisfy me i’m wrong”, as true, let alone axiomatic, and nor should i (a fortiori, i don’t live my life by anything remotely like such a “principle”).

I did not say: “bad is what i say” - as if I were some kind of an authority. I said that if something is perceived as “bad” when it comes to human beings than it cannot be automatically accepted as “good” if God does the same.

Since we are having fun with principles: the old Romans said: “Quod licet Iovi, non licet bovi”, and I disagree with that principle.

All I said was that I measure equally, no matter who commits / omits / allows / tolerates an act. In other words: “justice must be blind”. Why do you find that principle problematic?

 

[ceedre]

Prove, right, it was too late for me to be up last night.

Ok, I pretty much get what was going on in the debate now. Zindler said that “atheism doesn’t make any claims” or as ateista says, it is only a “lack of belief”. Craig contends that atheism does make a claim- that God (or a god) does not exist.
I tend to think that atheism does indeed claim that God/god does not exist, and that a “lack of belief” is agnosticism, not atheism.

Anyways, I the rest of the debate here is really interesting. I especially liked this part-

ateista:

I really don’t want to go into semantics, but “agnostic” is an epistemological term, while “theist” and “atheist” are metaphysical ones. Technically we are all “agnostics” because we do not know if God exists or not. Huxley coined the term “agnostic” and it is used as a middle gound, which is unjustified. One either has a belief in God’s existence (theist) or lacks the belief (atheist).

john doran:

they’re all epistemological terms, since they all describe belief-states.

ateista:

If anyone would know, the belief would be useless.

john doran:

not true: knowledge is just belief of a certain kind. some say “justified and true”, others, “formed under the right conditions”, and so on…

 

[ateista]

I tend to think that atheism does indeed claim that God/god does not exist, and that a “lack of belief” is agnosticism, not atheism.

Agnosticism is just a “cop-out”. One either believes or does not believe. There is no middle ground.

The term “theist” means someone who believes in the existence a god or gods. The term “atheist” means someone who does not believe in the existence of a god or gods. Both refer to “existence” which is part of metaphysics.

The term “agnostic” refers to someone who says: “we do not know if a god or gods exist, therefore we must suspend judgment”. It refers to the “knowledge”, which is part of epistemology.

As a short and playful summary:

Metaphysics: “what exists?”
Epistemology: “how do we know it?”
Ethics: “so, what now?”

Some make a distinction between “strong atheism” and “weak atheism”. The strong atheist says “the concept of a god or gods is nonsensical; so I believe that there is no such being”. A weak atheist simply says: “I see no reason to believe that a god or gods exist, so I lack the belief.”. Both are **explicit **atheists.

Then there are the **implicit **atheists, who never even heard of a god or gods, and those who are unable to comprehend such concepts. Since the word “theist” means someone who has a belief in a god or gods, these people are not theists. They lack the belief, so they are “weak atheists”. Examples are young children, or mentally retarded people.

 

[john_doran]

I did not say: “bad is what i say” - as if I were some kind of an authority. I said that if something is perceived as “bad” when it comes to human beings than it cannot be automatically accepted as “good” if God does the same.

…we’ve already gone over this in another thread.

whether or not something done by a human being is morally bad depends on why she did that thing. so, if we know that a person did something for morally unrectifiable reasons, then that person has acted immorally.

when it comes to god, though, we don’t know why he does the things he does. so, the argument is that if you have good reason to believe that god is good, then you also have good reason to think that god’s reasons for doing the things he does are ***also ***good, even if you don’t know what those reasons are.

no one is suggesting that reasons for action that are immoral for humans are not immoral for god.

ateista:

All I said was that I measure equally, no matter who commits / omits / allows / tolerates an act. In other words: “justice must be blind”. Why do you find that principle problematic?

i don’t. what i find problematic is your ancillary principle that god can only act justly if he explicitly explains why he does what he does.

 

[john_doran]

The term “theist” means someone who believes in the existence a god or gods. The term “atheist” means someone who does not believe in the existence of a god or gods. Both refer to “existence” which is part of metaphysics.

The term “agnostic” refers to someone who says: “we do not know if a god or gods exist, therefore we must suspend judgment”. It refers to the “knowledge”, which is part of epistemology.

look, the proposition “there is no god” is a metaphysical proposition. but the proposition “i believe that there is no god” is epistemological.

you make the very same point when you say this:

ateista:

Some make a distinction between “strong atheism” and “weak atheism”. The strong atheist says “the concept of a god or gods is nonsensical; so I believe that there is no such being”. A weak atheist simply says: “I see no reason to believe that a god or gods exist, so I lack the belief.”. Both are **explicit **atheists.

Then there are the **implicit **atheists, who never even heard of a god or gods, and those who are unable to comprehend such concepts. Since the word “theist” means someone who has a belief in a god or gods, these people are not theists. They lack the belief, so they are “weak atheists”. Examples are young children, or mentally retarded people.

atheism, theism, and agnosticism all refer to beliefs, and are thus in the domain of epistemology.

 

[ateista]

…we’ve already gone over this in another thread.

whether or not something done by a human being is morally bad depends on why she did that thing. so, if we know that a person did something for morally unrectifiable reasons, then that person has acted immorally.

Accepted.

And if we do not have any evidence either way - then what? If we must form a judgment based on incomplete information - what principle do we use then? In my opinion there is no better solution than the “duck principle”. As always, I am open to an alternative suggestion. Maybe you have a better principle, and if so, I will be glad to hear it.

when it comes to god, though, we don’t know why he does the things he does. so, the argument is that if you have good reason to believe that god is good, then you also have good reason to think that god’s reasons for doing the things he does are ***also ***good, even if you don’t know what those reasons are.

no one is suggesting that reasons for action that are immoral for humans are not immoral for god.

Accepted with one provision.

You said: “if you have good reason to believe that god is good” and that is precisely my question: “how you you plan to substantiate that you have **good reason **to believe that God is good, **without **reflecting on the actual instances and showing how are they good?”. You cannot just say that “God is good” is an axiom - and expect me to agree with you.

i don’t. what i find problematic is your ancillary principle that god can only act justly if he explicitly explains why he does what he does.

I do not expect God to come down and do the explanation. I cannot do so since I do not believe that God exists. I am, however, open to any explanation you may offer. If there is no explanation, then I am left to my own devices, and will decide on the available evidence - which is exactly none; and thus we are back to my question: what method do we use to make a judgment call when we lack complete information?

 

[IvanKaramozov]

What about the claim that an “Invisible Pink Unicorn” does not exist?

At a glance one can easily prove that the “Invisible Pink Unicorn” does not exist. After all “invisible” and “pink” cannot be reconciled. But what do the unicornists say to that? They say that it is the mystery of the Unicorn, not subject to rational scrutiny. One must accept it on faith that the Unicorn is both invisible and pink and there is no problem.

Impasse.

The anti-unicornists say that there never was an actual sighting or any physical evidence for the Unicorn and thus the existence of the Unicorn cannot be taken seriously. The unicornists counter this by pointing out that the Unicorn exists out of time and space.

Impasse again.

Now comes the real problem. The unicornists assert that the Unicorn issued some commandments in which it described the correct Absolute Morality by which one must lead his life. Furthermore they demand that those commandments be reflected by the secular laws, and everyone should adhere to them.

And this is the point when the anti-unicornists stand up and say “Whoa”. They start to demand evidence for the Unicorn. They have no problem with the unicornists beliefs as long as they do not wish to impose their views on others. But the unicornists are adamant. They say that the anti-unicorninsts want to impose their disbelief on them, by removing the Unicorn from the schools, by enacting laws which are clear violations of the Unicorn’s commandments.

And the merry-go-round just keeps spinning…

The question is: should any claim be given serious consideration? No matter how outlandish the claim is?

The only possible answer is: “NO”. If someone wants to assert the existence of anything, and wishes to be taken seriously, then he MUST present evidence for his claims.

To demand that the disbelievers must present “proof” for the nonexistence of the Unicorn is a feeble attempt to avoid the conclusion: the claims of the Unicornists are nonsensical.

This is a false setting

IF we are in some adversarial setting, like a debate, and I make an assertion at you, then it is my burdern of proof to back up this assertion. So in a debate you are correct.

Now, in a regular setting, you are incorrect. If you and I are talking on a street corner, and a man walks up to us and says, Do you beleive in the IPU?

Now, if you say no, you must supply a justification(as must I if I say yes), if you go furter and say, “no, I do not as there is no evidence for it” This is a claim you must justify.

In a debate an atheist has no burden of proof, in a natural setting, he/she does.

 

[ateista]

This is a false setting

IF we are in some adversarial setting, like a debate, and I make an assertion at you, then it is my burdern of proof to back up this assertion. So in a debate you are correct.

Now, in a regular setting, you are incorrect. If you and I are talking on a street corner, and a man walks up to us and says, Do you beleive in the IPU?

Now, if you say no, you must supply a justification(as must I if I say yes), if you go furter and say, “no, I do not as there is no evidence for it” This is a claim you must justify.

In a debate an atheist has no burden of proof, in a natural setting, he/she does.

Are you serious? If anyone walks up to me and asks if I believe in the existence of gods, angels, demons, leprechauns, fairies, drangons, elves, etc… then I have to substantiate my lack of belief? Why should I be required to do that?

The lack of belief is the default position. It does not have to be substantiated. No one is born with any of these or similar beliefs.

As a matter of fact I don’t think that the believers are under any obligation to substantiate their beliefs - as long as they hold them as personal convictions and do not demand to be taken seriously.

If someone happens to believe in the existence of Santa Claus or the tooth fairy or an honest laywer, or a non-crooked politician - that is his business. Only if he wishes to impose his beliefs on me, will I require some evidence that his belief merits consideration, and it is not the product of a confused mind.