If there is one natural talent – a gift, even – that all humans possess, it is a natural talent to be irrational. It seems to be innate, in the same way that birds build their nests without training. And when people are arguing their case, in whatever scenario, they all manage to say the same wrong things. It’s as if everyone has been on a training course in stupidity.
The most common mistake I seem to come across is what is called “the argument to ignorance” or more formally, “argumentum ad ignorantiam.” Everyone uses it automatically when they are asked to prove the nonsense claim they are making. It goes like this:
Paranormal “expert”: “Spirit possession real.”
Skeptic: “Can you prove that spirit possession real?”
Paranormal “expert”: “ I’ll just throw the question back to you: can you prove that it is not?”
Now hang on a minute. When someone makes a claim, especially a very extraordinary claim like spirit possession, for which there is absolutely no confirmable evidence, the onus is upon the person making the claim to prove it. Why should that onus suddenly be put upon the person who is asking for evidence?
The basis of this fallacy is the claim – or more usually the implication – that because something cannot be proven false then it should be assumed to be true. And conversely that because a claim cannot be proven to be true then it should be assumed to be false. It is a fallacy of irrelevance, because the existence of a claimed phenomenon relies on the evidence that supports it. If one does not know (is ignorant of) the existence or otherwise of a claimed phenomenon, there is no logical basis for anyone to claim that because you do not “know” that ghosts or whatever don’t exist, that you should accept their existence – even tentatively.
But it’s an easy get-out for blowhards who claim paranormal expertise. The paranormal is just unsubstantiated tosh (I will change my opinion when someone demonstrates its existence unequivocally) and self-styled experts rely on their innate irrationality to gull the unwary, who are often equally irrational. (There are, of course, some deliberate frauds out there, but I’m not talking about them.)
If you find yourself in a discussion with a believer in the paranormal (or worse, an “expert”) then I would suggest that you don’t even bother. But if you must, then keep in mind the “argument to ignorance”; these people always make outright claims that they cannot support with confirmable evidence. Just ask them for the evidence, and don’t be waylaid by what you now know is about to be thrown at you. You are entitled to ask for evidence for any extraordinary claim, and it is not up to you to disprove something that has no proof of its own. Nowadays, in the age of the internet, such a scenario might go like this:
Paranormal “expert”: Ghosts are real.”
Skeptic: “Can you prove that ghosts are real?”
Paranormal “expert”: “Can you prove that they are not?”
Skeptic: “You have just committed the logical fallacy known as argumentum ad ignorantiam.”
Paranormal “expert”: “You are wrong. And I might just sue you for saying so. Retract your statement and apologise, or else.”
(Legal thuggery is becoming commonplace on the internet these days as a means of stifling criticism: “I don’t have an argument, but I do have a lawyer.”)
Getting into a conversation with a believer or self-proclaimed expert is not very productive, however. You will not change the mind of someone who is closed-minded. (By the way, it is not open-minded to believe unsubstantiated crap; being open-minded just means being open to the possibility that you might be wrong – and being prepared to change your opinion in the light of new evidence. To be honest, I can only shake my head in astonishment and chuckle inwardly when those who offer evidence-free claims of the paranormal accuse me of being closed-minded.)
The Bottom Line
The Argument to Ignorance is a fallacy of irrelevance. The claim or implication that something is true because it cannot be proven false (or false because it cannot be proven true) is a common fallacy. The burden of proof is always upon the person who makes a claim – and the more extraordinary the claim, the more extraordinary the evidence that is required to substantiate it.
The fallacy is most often presented in response to a request for the claimant to supply evidence. When your debating opponent turns your request back over to you to prove him wrong, rather than proving their case with strong evidence, he or she is committing the fallacy of The Argument to Ignorance.
Don’t fall for it.