Can we know that something doesn't exist?

@Night Ripper,

Night Ripper;136921 wrote:

If you're saying that "square circle" implies a contradiction much like "married bachelor" then you'll get the same analysis as before. It refers to no concept at all and there is no concept to instantiate.

If it refers to no concept at all, then there is no concept to instantiate, of course. Does "round circle" refer to a concept? It it does, then why should not its contrary, "square circle' not refer to a concept. I am afraid that you do not distinguish between the fact that a particular concept is not instantiated, like the concept of a Martian, and the different fact that it would be impossible for a concept to be instantiated, like the concept of a square-circle.

@kennethamy,

kennethamy;136924 wrote:

I am afraid that you do not distinguish between the fact that a particular concept is not instantiated, like the concept of a Martian, and the different fact that it would be impossible for a concept to be instantiated, like the concept of a square-circle.

But I have. Don't you remember me talking about the river of cola? The same thing applies to Martians or any other contingent entity. I covered married bachelors as well. It's impossible for a "married bachelor" to exist, or in other words, there is nothing that instantiates the concept of "married bachelor", because "married bachelor" refers to no concept at all. The concepts of "married" and "bachelor" exclude each other.

@Night Ripper,

Night Ripper;136927 wrote:

But I have. Don't you remember me talking about the river of cola? The same thing applies to Martians or any other contingent entity. I covered married bachelors as well. It's impossible for a "married bachelor" to exist, or in other words, there is nothing that instantiates the concept of "married bachelor", because "married bachelor" refers to no concept at all. The concepts of "married" and "bachelor" exclude each other.

It is contingent that nothing is a Martian. It is necessary that nothing is a square-circle. But that does not mean that the term, "square-circle" is meaningless, or, as you put it there is no concept of a married bachelor. If there were none, then how would we know that there was no such thing? That, of course, returns us to the original OP. We do know that married bachelors do not exist because we know that it is logiclly impossible for them to exist. And we know that there is nothing that freezes at 70 degrees F. because it is physically impossible for anything to do so. And, by the way, we know that it is technologically impossible to fly to other galaxies because it is technilogicaly impossible to do so (the technology has not yet been invented).

@kennethamy,

kennethamy;136929 wrote:

But that does not mean that [...] there is no concept of a married bachelor. If there were none, then how would we know that there was no such thing?

Your claim is that there is a concept of a "married bachelor" but I don't know what it could be. I know what "married" means. I know what "bachelor" means. What does "married bachelor" mean?

@Night Ripper,

Night Ripper;136931 wrote:

Your claim is that there is a concept of a "married bachelor" but I don't know what it could be. I know what "married" means. I know what "bachelor" means. What does "married bachelor" mean?

A bachelor who is married. In fact, some of my friends are married bachelors; not that their wives are happy about it.

@kennethamy,

kennethamy;136929 wrote:

We do know that married bachelors do not exist because we know that it is logiclly impossible for them to exist.

kennethamy;136983 wrote:

In fact, some of my friends are married bachelors; not that their wives are happy about it.

Why do you insist on playing word games?

@Night Ripper,

Night Ripper;136999 wrote:

Why do you insist on playing word games?

Why is that a word game? You ask me what "married bachelor" means, and I reply that it means, "married bachelor". If "married bachelor" had no meaning then, "unmarried bachelor" would have no meaning. But not only is that false, but "all unmarried bachelor are bachelors" is a necessary truth. And no truth can be meaningless.

@kennethamy,

kennethamy;137056 wrote:

Why is that a word game?

It must be a game because it's not serious. What else would you call nonsense that rests on an ambiguous turn of phrase?

kennethamy;137056 wrote:

You ask me what "married bachelor" means, and I reply that it means, "married bachelor".

Yes, all words mean what they mean. That still doesn't tell me what "married bachelor" means.

kennethamy;137056 wrote:

If "married bachelor" had no meaning then, "unmarried bachelor" would have no meaning.

I don't see how that follows. A "married bachelor" implies a contradiction but an "unmarried bachelor" is just redundant. What's the connection? I see none.

@Night Ripper,

Night Ripper;137072 wrote:

It must be a game because it's not serious. What else would you call nonsense that rests on an ambiguous turn of phrase?

Yes, all words mean what they mean. That still doesn't tell me what "married bachelor" means.

I don't see how that follows. A "married bachelor" implies a contradiction but an "unmarried bachelor" is just redundant. What's the connection? I see none.

If I say that someone is wearing black shoes, what would you be intending if you asked me what that meant? My answer would be that it meant that he was wearing black shoes. And my reply is the same when you ask me what "married bachelor" means. I suppose you are saying that the term is meaningless. Then you would have to explain why the sentence, "There are no married bachelors" is meaningful (and true) but it contains a meaningless phrase. Can you?

@hue-man,

Okay. So no general theory of physical impossibility and no demonstration for the example discussed.

@ughaibu,

ughaibu;137089 wrote:

Okay. So no general theory of physical impossibility and no demonstration for the example discussed.

I gave a clear argument that had the example as a conclusion. So, what are you talking about?

If a country with no military forces has a war with a country with enormous military forces, it is physically impossible for the former to win.
Luxembourg is a country with no military forces, and China a country with enormous military forces.

Therefore, If L. goes to war with China, it is physically impossible that L will win. QED

Have you a problem with this argument?

@kennethamy,

kennethamy;137091 wrote:

If a country with no military forces has a war with a country with enormous military forces, it is physically impossible for the former to win.
Luxembourg is a country with no military forces, and China a country with enormous military forces.

Therefore, If L. goes to war with China, it is physically impossible that L will win. QED

Have you a problem with this argument?

Of course, and it's already been detailed on this thread.

@ughaibu,

ughaibu;137093 wrote:

Of course, and it's already been detailed on this thread.

And that is where? But please, if I do present an argument, don't say I did not.
You can have but two kinds of problem with the argument. 1. One or more or the premises is false. 2. the argument is invalid.

Check one, please.

My general theory of physical impossibility is the Deductive-Nomological theory of explanation. I have already cited that, too.

So please do not say I have offered no general theory of physical impossibility when I have.

@kennethamy,

kennethamy;137094 wrote:

My general theory of physical impossibility is the Deductive-Nomological theory of explanation.

Are you saying that "physical possibility" is an explanatory convenience term?

@ughaibu,

ughaibu;137095 wrote:

Are you saying that "physical possibility" is an explanatory convenience term?

No.............

But first, what about my argument that it is physically impossible for Luxembourg to win a war against China. There was such an argument wasn't there. And, if there was, why did you say I had not presented such an argument?

@kennethamy,

kennethamy;137096 wrote:

No.............

Then I dont see the relevance of the Deductive-Nomological theory of explanation. As far as I know, it's a theory of how scientific explanations work, how does that amount to a general theory of physical possibility?

kennethamy;137096 wrote:

But first, what about my argument that it is physically impossible for Luxembourg to win a war against China. There was such an argument wasn't there.

I've answered it, and I'm not sufficiently interested in argument by example to repeat myself.

@kennethamy,

kennethamy;137096 wrote:

No.............

But first, what about my argument that it is physically impossible for Luxembourg to win a war against China. There was such an argument wasn't there. And, if there was, why did you say I had not presented such an argument?

present some decent argument on that, you are clearly admitting that you were wrong, or that such assumption is a matter of personnel belief...:whoa-dude:

---------- Post added 03-07-2010 at 12:18 AM ----------

Since when the number of soldiers is the ultimate criteria for wining a war ? or since when the number of enemy's that you have, only amount to those who you can clearly identify ? Laughing

@ughaibu,

ughaibu;137097 wrote:

Then I dont see the relevance of the Deductive-Nomological theory of explanation. As far as I know, it's a theory of how scientific explanations work, how does that amount to a general theory of physical possibility?I've answered it, and I'm not sufficiently interested in argument by example to repeat myself.

So far as I can tell you have not replied to the argumennt at all. For you have neither commented on the premises, nor on the validity of the argument. Of course, your interest in the argument has nothing to do with whether it is an argument which illustrates how a an event can be shown to be philosophically impossible. If you let me know what sort of argument interests you, I will try to come up with that kind of argument. But any argument with is an example of proving that a particular event is physically impossible would meet the requirement. The DN model of explanation implies that an event which cannot be deduced from the relevant laws of nature, together with the current initial conditions is physically impossible. That should be obvious.

I hope this helps.

@kennethamy,

kennethamy;137104 wrote:

If you let me know what sort of argument interests you, I will try to come up with that kind of argument.

A general theory of physical possibility.

kennethamy;137104 wrote:

any argument with is an example of proving that a particular event is physically impossible would meet the requirement.

No it wouldn't, it would only work if you were offering a counter example.

kennethamy;137104 wrote:

The DN model of explanation implies that an event which cannot be deduced from the relevant laws of nature, together with the current initial conditions is physically impossible.

The thesis concerns laws of science, not laws of nature, presumably even necessitarian laws ontologists dont hold that laws of science are ontologically real entities with physically prescriptive power. And the thesis concerns the logic of explanations, so it is concerned with what is logically entailed by laws of science, ie the observation to be explained. In short, the thesis demands that an explanation be a logical argument with the inverted form of a prediction. There is no implication to the effect that it's impossible for the prediction to fail, and thus for the explanation to be falsified.

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Can we know that something doesn't exist?

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