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Can't Prove a Negative.

A lot of folks love to toss that statement around. But simply to look at it is to recognize the claim as a very stupid one. Simple logic will tell you that it's either wrong, or unproveable.

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

What the Fallacy means is that you cannot prove that which does not exist. For example, I can prove the existence of a horse by providing one to your senses. I cannot prove the existence of a Unicorn because there is no such thing to prove it to you as an example of.

This is why science no longer considers the existence of the "ether" as a valid explanation of the propagation of light and energy. There is no evidence for it and that Einstein's Theories hold sway. You have to give some evidence to support your proposition.

As it happens, as a general statement it is wrong. For example, in math it is quite common to prove negatives

This is the Fallacy of Conflation. Math is a theoretical system, not a physical one. 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.

ID cannot be prove to exist. By definition.

it's quite obvious that a negative statement such as "there are no green mammals" can be refuted by the simple expedient of producing a green mammal

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.

For example, the Assertion that Homosexuality is "unnatural" is refuted by examining the lives of Bonobo apes. They are very "perverted." If homosexuality is a moral issue then mere animals couldn't indulge in such behavior. If not, then the Fallacy holds.

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

I like all your fallacies, but they are not necessary.

Any thinking person can see the virtual impossibility of proving a negative. Even with one variable, the number of possible permutations that would require testing become enormous and thus practically impossible.

That's why scientists always design their experiments to produce positive evidence for something. Creationists are always saying that Pasteur disproved spontaneous generation. But that was not his experiments. He proved that broths became turbid with bacterial growth because bacteria were present in air. That is a positive proof, not a negative one.

The only thing that can ever be proved about spontaneous generation is that it exists. When some scientist shows a process for "life" appearing from "non-life" then spontaneous generation will become fact. It will never be disproved, because it is impossible to test every possible scenario.

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:
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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.