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If everyone had to prove that what they said was absolutely true before saying anything then nothing would get said as it is almost impossible to prove a positive.


Really? I thought it was almost impossible to prove a negative.

"You eat babies in your spare time!"

"No, no I don't."

The 1st can produce a picture of the person eating a baby, how does the 2nd prove that he doesn't eat babies?

If the person who had the claim made against them had to definitively prove that beyond a doubt he doesn't eat babies - he'd have to have had someone recording him for every minute of his waking life, including those moments prior to the claim.

The only way to prove a negative is to run a (perhaps nearly) infinite number of tests and never get that result.


There is no trouble in proving a negative that does not exist for proving a positive. For example, you can prove to your own satisfaction that there are no monkeys on your shoulder, even though that is a negative claim. The problem of proof to which you alluded with your example is just the famous problem of induction, which exists for both positive and negative claims.

The negative claim that so-and-so has never eaten a baby is difficult to prove because that claim is actually a group of claims: so-and-so was not eating babies at time one, time two, time three, etc. Each and every claim in that sequence could be proven with a photograph that shows so-and-so doing something other than eating babies. Each negative in that sequence is provable. The problem is the length of the sequence: you need hundreds and hundreds of proofs. You would have the same trouble with any similar sequence of positive claims, such as the sequence entailed by the statement that there is a human-habitable planet in one out of ten solar systems.


Exactly, it has nothing to do with negativity. What people generally mean is: "It's almost impossible to prove a universal proposition." This is because doing so would involve examining all things to which that proposition would apply.

That's equally difficult whether you're trying to prove that "All swans are white" or "No swans are black": the only ways to conclusively prove either involve examining large numbers of objects.


Really? I thought it was almost impossible to prove a negative.

Go read Karl Popper on falsifiability.


... and most of the examples shows proving a positive as well, and also clearly exerts why the statement I said in my post is not falsifiable. Your original statement, was, btw, "it is almost impossible to prove a positive." So, how is it nearly impossible to prove "this swan is white," but highly possible to prove "no swan has ever been black?"

I can prove there is a mouse that is blue and black on my desk, but I cannot prove that there has never been a red and black mouse on my desk, I can only assert such.


Why don't you try your best to summarize the pertinent aspects of falsifiability for the community? I'll try to start. Here's some background: http://en.wikipedia.org/wiki/Falsifiability


If everyone had to prove that what they said was absolutely true before saying anything then nothing would get said as it is almost impossible to prove a positive.

Doesn't the coexistence of the libel laws and the media industry kinda prove you wrong there?


I have no real knowledge of the law. But I thought it was more along the lines of, you have to have sufficient evidence. If it transpires you were wrong you're ok as long as you had good reason to think it was true.

I'm very intrigued to know how exactly the law works now.


I'm very intrigued to know how exactly the law works now.

I came across the following basic explanation a while ago, seems like a pretty decent write-up:

There are two versions of defamation, libel and slander. Libel is when the defamation is written down (including email, bulletin boards and websites), and slander is when the incident relates to words spoken.

In the UK, if someone thinks that what you wrote about them is either defamatory or damaging, the onus will be entirely on you to prove that your comments are true in court. In other words, if you make the claim, you've got to prove it!

For example, if you said Peter Sutcliffe had never paid his TV licence in his life that would not be defamatory - or it is very unlikely to be. However, if you said the same about TV boss Greg Dyke, that would be.

Why? Because Peter Sutcliffe's reputation will not be damaged by the TV licence revelation (he is after all a mass murderer). Of course, his lawyers would still be free to bring the case to court, but it is very unlikely they would succeed.

Greg Dyke, on the other hand, runs the BBC , so to say he wilfully doesn't pay his TV licence could have a seriously detrimental effect on his career. He could be fired or his reputation damaged (note:Dyke has now left the BBC).

Continued here:

http://www.urban75.org/info/libel.html


Similarly truth isn't an absolute defence. If I stated a particular politician was gay or had an abortion, every time my publication mentioned them - even if that was true - then if it was done purely malicously, ie. it had nothing to do with the article, that could be slander/libel.

There are exceptions for reporting legal judgements, which is why its important to always refer to the convicted liar Jeffery Archer


I'm really straining to see how you can be slandered by the fact of your sexuality.


Historically some people wanted to keep their sexuality private because they felt they might lose sales / votes / whatever if people knew their sexuality.

Don't forget that homosexuality has only relatively recently become legal in England.

The Jason Donovan case is particularly interesting.

(http://www.independent.co.uk/news/sad-about-the-boy-1270092....)

(http://en.wikipedia.org/wiki/Jason_Donovan)

(http://www.guardian.co.uk/world/2000/apr/17/law.claredyer)


Hopefully these days you couldn't be because nobody should care.

But if you were running say a local paper and you went out of your way to consistently describe a local politician or school teacher/principal as "the homosexual Mr Smith" and your intentions were malicious they could have a reasonable chance of damages from you.


You don't have to mathematically prove your case - just that you had reasonable grounds for stating it.




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