[r9etb]

What you prove is you don't understand the rules of logic.

I'm not the one who spouted "you can't prove a negative."

You're now trying to wriggle out of it by trying to say that you "really" meant "you can't prove things that don't exist in the first place." But words have meaning, and your original statement made no such fine distinctions.

What the Fallacy means is that you cannot prove that which does not exist.

You're still wrong. It is possible to demonstrate that certain assumptions lead to contradictions -- the search for contradiction is an established approach to logical and mathematical proofs. For example, if one can demonstrate that an assumption X leads to a contradiction, then the conclusion is that X does not exist. E.g., I once took an abstract linear algebra class in which the denoument was a proof that a certain proposed hypercomplex construct does not exist (I can't recall off-hand if it was a 16- or 32-D construct).

This brings us to a practical difficulty: can you prove your statement? Consider: in order for your statement to be true, before we can accept the supposed inability to prove, we must accept that "that which does not exist," really does not exist. But how does one prove that it does not exist? According to the first part of your statement, we cannot provide the necessary proof, and thus your statement is seen to have no logical meaning: it is unproveable by its own terms. But once again: in at least some cases we can prove that something does not exist, and thus we see that your statement is not generally true.

But I'll throw you a bone: you may simply be saying that it's impossible to prove that something does exist, if in fact it does not exist. But again: in practical terms you're still stuck trying to prove non-existence.

This is the Fallacy of Conflation. Math is a theoretical system, not a physical one. The rules are different.

You're still trying to add conditions to your original, very general, claim. Nevertheless, math happens to have an uncanny ability to describe physical reality far better than we can sense it. For something like that, you're going to have to do a lot better than simply to state without proof that "the rules are different."

It is possible to prove a statement wrong but it is not possible to prove a fact wrong. Volcanoes exist. Rivers exist. Bears exist. Evolution exists.

Always assuming, of course, that people only state "facts." But of course many "facts" really aren't facts at all, but rather convenient approximations or even outright errors. Neither you nor I are capable of perfect knowledge about anything -- which means that neither of us has any complete "facts" at our disposal. The Theory of Evolution is a good example: despite its maintaining a consistent name, the theory itself is difficult to pin down as "fact," because its definition is subject to change -- many "evolution facts" from 1912 are considered to be erroneous today; and what's "known" today might well be tossed out in the future.

ID cannot be prove to exist. By definition.

But Intelligent Design can be proven to exist -- for example, production of human insulin using recombinant DNA techniques. This is an explicit example of intelligent design, practiced by humans. Thus it is demonstrably possible to prove ID in at least some cases. Your general statement is thus refuted by empirical evidence. Now, it's certainly valid to argue about whether or not intelligent design -- especially ancient ID -- can be detected even if it did occur. However, to state that "by definition" it cannot be detected is to surrender any claim to being scientific: you're claiming perfect knowledge, and thus no need for proof. Because you've not got the former, you lack standing to "define" anything as you have. One might be excused for thinking that you're making an ideological claim, rather than a logical and scientific one.

This is known as the "White Crow Fallacy" since it would require examining every crow in the Universe to prove there are no "White Crows." This is why in logic the Burden of Proof is upon whoever is making the Assertion.

Ah, but cute names aside you're not describing a logical fallacy, but rather a practical difficulty. Your inability and/or unwillingness to search the entire universe has no bearing on the logical truth or falsity of the statement itself. Nevertheless, it is rather easy to refute the "no white crows" claim:
.

One cannot prove one thing true by proving another thing false. Keep studying. You might understand this truth someday.

Of course, I've not attempted to prove anything except that your statements are logically unsound. I've made no claims about anything else, and thus am not impressed by your suggestions to the contrary. But I'm sure your logical wings have taken you far enough that you can recognize a red herring when you commit one.

[furball4paws]

LW's use of white crow, in no way invalidates the fallacy. Albinism is common crows is "Relatively frequent" with approximately 100 sightings. In fact albinism is quite common in many birds (especially Turdus migratorius, so you can find a picture. But the use of "White Crow Fallacy" is simply illustrative, as you know. You just chose to ignore it.

Ref. John K. Terres. 1980. The Audubon Encyclopedia of North American Birds

[LogicWings]

You're now trying to wriggle out of it by trying to say that you "really" meant "you can't prove things that don't exist in the first place." But words have meaning, and your original statement made no such fine distinctions.

No my mistake was assuming I was conversing with an educated person who understood the rules of logic and what the Fallacy "Can't Prove a Negative" actually refers to. Clearly I am not conversing with such a person.

You're still wrong.

No, I'm not, and the rest of your little homily makes the point I was elucidating. You actually verified my position without even understanding you did so.

But how does one prove that it does not exist?

One doesn't prove it "does not exist" which is why the Burden of Proof in logic and science is upon the person making the Assertion. Basic stuff you don't seem to understand. I don't have to prove it "doesn't exist" since this is impossible, you have to prove it does for it to be considered a valid assertion. Once again, basic stuff.

According to the first part of your statement, we cannot provide the necessary proof, and thus your statement is seen to have no logical meaning: it is unproveable by its own terms.

No it isn't. Logic says that you cannot provide proof for that which doesn't exist, by definition. There is no need to prove this fact, it is axiomatic, by definition.

I once took an abstract linear algebra class in which the denoument was a proof that a certain proposed hypercomplex construct does not exist.

I've already been here once, the definition excludes its existence. There are no square circles. This is not the same as asserting the Cyclops, or Bigfoot, exists. You have to provide evidence for one first for it to be considered as valid.

But again: in practical terms you're still stuck trying to prove non-existence.

I don't have to. You have the Burden of Proof to validate any assertion, otherwise it is just your fantasy. Like the ether or Mesmerism.

For something like that, you're going to have to do a lot better than simply to state without proof that "the rules are different."

Don't know what Conflation is, do you? Hand me a number. Mix me up a bowl of sums. You see, math is an abstract and whether it describes reality or not is irrelevant, it is just language. It is not the actual physical thing that is being described. That is the difference. Proving a Negative, for anyone who has studied logic, is about proving the existence of something "physical" i.e., evidence. Which is the focus of this discussion. Which you are trying so very hard to avoid. Reality.

But Intelligent Design can be proven to exist

Conflation again. ID as it is being introduced to be taught in schools concerns itself with "non-natural" sources of design.

However, to state that "by definition" it cannot be detected is to surrender any claim to being scientific: you're claiming perfect knowledge, and thus no need for proof.

The insistence that "non-natural" (or supernatural) sources of design be included as "science" means that, by definition, we are incapable of detecting them since the natural world is all we can "scientifically" detect. Just like a "square-circle" or a "16- or 32-D construct" cannot exist, neither can "non-natural" evidence. It is a contradiction in terms. If you don't see that, that is your problem. Logically, I am correct, by definition. Doesn't require my omniscience.

Ah, but cute names aside you're not describing a logical fallacy, but rather a practical difficulty.

Same thing. You just keep dodging by that Burden of Proof. And the crummy picture looks like a parakeet, not crow. Prove otherwise.

I've not attempted to prove anything except that your statements are logically unsound.

And failed. All you proved is you don't understand the rules of logic and the nature of fallacies.