Can we know that something doesn't exist?

@Zetherin,

Zetherin;137227 wrote:

It's not just because I've never seen it. It's because water does not freeze at 70 degrees. It is because water molecules freezes at 32 degrees. Isn't it true that water molecules freeze at 32 degrees? And don't you think scientists would say it is impossible for water to freeze at 70 degrees, since water freezes at 32 degrees?

Perhaps this link will help you: Water

Yes that link does help me. It helps me see that you're a) not taking this seriously anymore and b) think it's cute to insult the intelligence of others by linking them to articles for grade school level points.

I'm well aware of the freezing temperature of water. The question is about physical impossibility which your joke/article doesn't actually cover.

Do you have anything constructive to say or will you continue to adopt kennethamy's argumentative style?

@Night Ripper,

Night Ripper;137229 wrote:

Yes that link does help me. It helps me see that you're a) not taking this seriously anymore and b) think it's cute to insult the intelligence of others by linking them to articles for grade school level points.

I'm well aware of the freezing temperature of water. The question is about physical impossibility which your joke/article doesn't actually cover.

Do you have anything constructive to say or will you continue to adopt kennethamy's argumentative style?

Well, to be honest, I do think this is a silly conversation. We were sincerely arguing over the temperature it takes water to freeze? The resources are available.

Alright, so you just admitted that you're aware of the freezing temperature of water, so I will take that as you saying you believe, "Water molecules freeze at 32 degrees" is true. So, you should be able to now understand why it is impossible for water to freeze at 70 degrees. Right?

I never knew I would have to argue about such common knowledge on a philosophy forum. Sorry, I should be more understanding, because maybe you just forgot. Hopefully it's all cleared up now since you remembered the temperature it takes water to freeze.

@Zetherin,

Zetherin;137232 wrote:

We were sincerely arguing over the temperature it takes water to freeze?

No we're not. The problem is that you've forgotten about the "principle of charity". It's usually good manners to assume the other person isn't a drooling retard. Perhaps, just perhaps, their point is a bit more subtle than your hamfisted remarks acknowledge.

Zetherin;137232 wrote:

Alright, so you just admitted that you're aware of the freezing temperature of water, so I will take that as you saying you believe, "Water molecules freeze at 32 degrees" is true. So, you should be able to now understand why it is impossible for water to freeze at 70 degrees. Right?

No, I don't. Please explain to me how the fact that something does happen means that it has to happen? This sounds like the modal fallacy.

Zetherin;137232 wrote:

I never knew I would have to argue about such common knowledge on a philosophy forum.

We weren't arguing about that. You were. We're talking about physical impossibility. Please join the discussion instead of beating up that poor straw man.

@Night Ripper,

Night Ripper;137229 wrote:

Yes that link does help me. It helps me see that you're a) not taking this seriously anymore and b) think it's cute to insult the intelligence of others by linking them to articles for grade school level points.

I'm well aware of the freezing temperature of water. The question is about physical impossibility which your joke/article doesn't actually cover.

Do you have anything constructive to say or will you continue to adopt kennethamy's argumentative style?

My argumentive style:

1. If water freezes at 32 degree, then it is physically impossible for it to freeze at 70 degrees.
2. Water freezes at 32 degrees.

Therefore, 3. It is physically impossible for water to freeze at 70 degrees.

Can you say what you believe is wrong with that argument. Logicians and scientists would , I am sure, say it is sound. Apparently you disagree. Any particular reason?

I think that everyone (particularly you) would do well to adopt that argumentive style.

@hue-man,

A necessary truth is that water is H2O, but you are saying that water's freezing point is a contingent truth? But water's freezing at 32 degrees seems to be an essential property, and wouldn't that mean that it is impossible water could freeze at 70 degrees?

@kennethamy,

kennethamy;137241 wrote:

My argumentive style:

1. If water freezes at 32 degree, then it is physically impossible for it to freeze at 70 degrees.
2. Water freezes at 32 degrees.

Therefore, 3. It is physically impossible for water to freeze at 70 degrees.

Can you say what you believe is wrong with that argument. Logicians and scientists would , I am sure, say it is sound. Apparently you disagree. Any particular reason?

The modal fallacy claims another victim. :Not-Impressed:

See 'The' Modal Fallacy - Prof. Norman Swartz and in particular:

Quote:

'If p is true, then p cannot be false'
[INDENT] "If a proposition is true (/false), then it cannot be false (/true). If a proposition cannot be false (/true), then it is necessarily true (/false). Therefore if a proposition is true (/false), it is necessarily true (/false). That is, there are no contingent propositions. Every proposition is either necessarily true or necessarily false. (If we could see the world from God's viewpoint, we would see the necessity of everything. Contingency is simply an artifact of ignorance. Contingency disappears with complete knowledge.)" [/INDENT]The fallacy arises in the ambiguity of the first premise.

@Zetherin,

Zetherin;137242 wrote:

A necessary truth is that water is H2O, but you are saying that water's freezing point is a contingent truth? But water's freezing at 32 degrees seems to be an essential property, and wouldn't that mean that it is impossible water could freeze at 70 degrees?

Isn't all that is being claimed it that it is physically impossible that water should freeze as 70, not that it is metaphysically or logically impossible. Maybe that is true, but we do not have to make that claim? In other words, that it is contrary to the laws of physics.

---------- Post added 03-07-2010 at 01:23 PM ----------

Night Ripper;137243 wrote:

The modal fallacy claims another victim. :Not-Impressed:

See 'The' Modal Fallacy - Prof. Norman Swartz and in particular:

I am not committing the modal fallacy. Why do you say I am? Are you sure you know what that fallacy is? The scope of "impossibility" is no different in the premise than it is in the conclusion. So, back up your claim.

@Night Ripper,

Back to the question of a general theory of physical possibility. So far, all that has been offered is this:

kennethamy;137109 wrote:

The general theory of physical impossibility is an implication of the DN model. It is physically impossible for an event to occur unless it can be deduced on the lines of the DN model.

As far as I can see, the deductive-nomological theory of explanation fails as a general theory of physical possibility, as follows.
The deductive-nomological theory of explanation, is specifically a theory of what scientific explanations consist of, so, if Kennethamy's claim is to be accepted, the only physically possible events are events that are amenable to a scientific explanation. Further, the type of explanation required has the form of a prediction, either deterministic or probabilistic, thus, Kennethamy's claim entails that all physically possible events are members of sets of outcomes described by predictive algorithms. But, in a world as described by the best physical theories real numbers represent real quantities, so, while the number of predictive algorithms is, at most, countably infinite, the number of events is uncountable infinite. This means either that the best physical theories are wrong or that the set of possible events has zero measure. If the deductive-nomological theory carries the corollary that the best physical theories are wrong, I think it fails as a theory of scientific explanation, but if the set of physically possible events has zero measure, then the probability of any event, in a world described by the best physical theories, occurring, is zero. Both possibilities appear to be false, so I reject Kennethamy's general theory of physical possibility.

@kennethamy,

kennethamy;137244 wrote:

I am not committing the modal fallacy. Why do you say I am? Are you sure you know what that fallacy is? The scope of "impossibility" is no different in the premise than it is in the conclusion. So, back up your claim.

I backed up my claim with that article. Read it and see that you're making the same fallacy. If you can't see it then I don't know what else to do for you other than offer my condolences.

@kennethamy,

kennethamy;137241 wrote:

My argumentive style:

1. If water freezes at 32 degree, then it is physically impossible for it to freeze at 70 degrees.
2. Water freezes at 32 degrees.

Therefore, 3. It is physically impossible for water to freeze at 70 degrees.

Can you say what you believe is wrong with that argument.

It fails to do what was requested, and that is to distinguish what does happen from what can happen. Your argument amounts to an assertion that what doesn't happen is impossible.

@Night Ripper,

Night Ripper;137248 wrote:

I backed up my claim with that article. Read it and see that you're making the same fallacy. If you can't see it then I don't know what else to do for you other than offer my condolences.

But I am not making the modal fallacy. Show me that my argument is anything like the example you offered. It isn't

It is not up to me to show it isn't. It is up to you to show that it is. Giving an example does not show that my argument is like that example. You have to show it is like that example. And that is exactly what you have not done. You have alleged that it is like that example. But there is no similarity at all between my argument and the example. I don't think you know what you are talking about. And that is being charitable.

@hue-man,

kennethamy wrote:

Isn't all that is being claimed it that it is physically impossible that water should freeze as 70, not that it is metaphysically or logically impossible. Maybe that is true, but we do not have to make that claim? In other words, that it is contrary to the laws of physics.

I initially thought that all we were talking about when we said physical impossibility was what was contrary to the laws of physics. But evidently we are not.

ughaibu wrote:

It fails to do what was requested, and that is to distinguish what does happen from what can happen. Your argument amounts to an assertion that what doesn't happen is impossible.

But he is using physical impossibility to mean that which is contrary to the laws of physics. I thought that's how we ought to be using it, too. How are you using it again? Can you provide me an example of something which is physically impossible?

@kennethamy,

kennethamy;137251 wrote:

Show me that my argument is anything like the example you offered.

Let me quote you, then the article and explain it for you.

kennethamy;137241 wrote:

1. If water freezes at 32 degree, then it is physically impossible for it to freeze at 70 degrees.
2. Water freezes at 32 degrees.
Therefore, 3. It is physically impossible for water to freeze at 70 degrees.

The article:

Quote:

If Paul has one daughter and two sons, then Paul has to have at least one son.
Paul has one daughter and two sons.
Paul has to have at least one son.

Replace "Paul has to" with "it is physically impossible for Paul not to" and talk about daughters and sons to water freezing and it's the same fallacious argument.

The fact that water freezes at 32 degrees means it doesn't freeze at 70 degrees, not that it can't.

@Zetherin,

Zetherin;137253 wrote:

I initially thought that all we were talking about when we said physical impossibility was what was contrary to the laws of physics. But evidently we are not.

But he is using physical impossibility to mean that which is contrary to the laws of physics. I thought that's how we ought to be using it, too. How are you using it again? Can you provide me an example of something which is physically impossible?

I am using it that way. I have no idea how anyone else is using the term. Anyway, that is what the term means. Some people are linguistic Humpty-Dumptys. They decide to use terms according to their own whim (and, maybe, pay them extra. I hope so. At least, time and a half).

@Zetherin,

Zetherin;137253 wrote:

But he is using physical impossibility to mean that which is contrary to the laws of physics.

But I've just shown (post 348) that his claim based on laws of physics fails. In any case, what law of physics requires water to remain unfrozen at 70 degrees F? You realise that it can be frozen at any temperature below its critical temperature?

Zetherin;137253 wrote:

Can you provide me an example of something which is physically impossible?

I'm not really interested in the discussion of examples. I think that in any case impossibility is a logical matter, and I'd like to see those who disagree, offer and defend a satisfactory theory of physical possibility.

@hue-man,

ughaibu wrote:

You realise that it can be frozen at any temperature below its critical temperature?

Water can be frozen at any temperature below 705.2 degrees Fahrenheit? Source?

@ughaibu,

ughaibu;137257 wrote:

You realise that it can be frozen at any temperature below its critical temperature?

Sorry, this is a mistake, I was thinking of boiling.

---------- Post added 03-08-2010 at 03:58 AM ----------

Zetherin;137260 wrote:

Water can be frozen at any temperature below 705.2 degrees Fahrenheit? Source?

Okay. Any comment on the rest of the post. If I hadn't made a mistake with that point, it would've been so minor as to be hardly worth a mention!

@ughaibu,

ughaibu;137261 wrote:

Sorry, this is a mistake, I was thinking of boiling.

---------- Post added 03-08-2010 at 03:58 AM ----------

Okay. Any comment on the rest of the post. If I hadn't made a mistake with that point, it would've been so minor as to be hardly worth a mention!

Alright, well, can you provide me a source where I can read the definition of physical impossibility? That is not minor. That is the issue.

@Zetherin,

Zetherin;137263 wrote:

Alright, well, can you provide me a source where I can read the definition of physical impossibility?

This is the source, here. This is what we're discussing. If there is physical possibility, what is it? What is the general theory that distinguishes it from other forms of possibility.

@Night Ripper,

Night Ripper;137255 wrote:

Let me quote you, then the article and explain it for you.

The article:

Replace "Paul has to" with "it is physically impossible for Paul not to" and talk about daughters and sons to water freezing and it's the same fallacious argument.

The fact that water freezes at 32 degrees means it doesn't freeze at 70 degrees, not that it can't.

That is right.

My argument was:

1. If water freezes at 32 degree, then it is physically impossible for it to freeze at 70 degrees.
2. Water freezes at 32 degrees.

Therefore, 3. It is physically impossible for water to freeze at 70 degrees.

I am not sure, but are you questioning my first premise? But that first premise is true. I did not say that if water freezes at 32, then it is logically impossible that it should freeze at 70. Of course not. I said that it would physically impossible that it should freeze at 70. And that is true. For if the laws of nature are such that it freezes at 32, then for it to freeze at 70 would require a change in the laws of nature. The laws of nature cannot be such that water freezes at both temperature. You are confusing logical impossibility with physical impossibility. But for all I know you are not questioning my first premise. In that case, I don't know what you are talking about, since the argument is clearly valid.

Water freezes at 32 because it is physically possible for water to freeze at 32. And that means that it is consistent with the laws of nature for water to freeze at 32; and water does not freeze at 70 because it is inconsistent with the laws of nature (or physically impossible) for water to freeze at 70, therefore, if water freezes at 32 (which it does) then is is physically impossible for it to freeze at 70 (and it does not).

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Can we know that something doesn't exist?

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