This fallacy occurs when the burden of proof is placed on the wrong side of an argument. In a logical argument, the “burden of proof” lies with the individual making the claim; in other words, if you claim something, you need to provide the evidence for that claim. When you “shift the burden of proof,” instead of providing evidence to support their claim, you challenge your opponent to disprove it, believing that the inability to disprove it then means that your argument is credible. What we don’t know cannot be used as evidence for or against anything. Absence of knowledge is not knowledge, or as Martin Rees put it, “Absence of evidence is not evidence of absence.”
In the American legal system, the burden of proof lies with the prosecution, and the accused is “innocent until proven guilty.” If you claim that Bigfoot exists, psychic powers are real, or telekinesis is possible, then you have the burden of proof and must provide the evidence to support it.
Examples:
“Space-aliens are everywhere among us, even here on campus, masquerading as true humans! I dare you prove it isn’t so! See? You can’t! That means you have to accept that what I say is true.”
Bertrand declares that a teapot is, at this very moment, in orbit around the Sun between the Earth and Mars, and that because no one can prove him wrong, his claim is therefore a valid one.
Bill: “I think that we should invest more money in expanding the interstate system.”
Jill: “I think that would be a bad idea, considering the state of the treasury.”
Bill: “How can anyone be against highway improvements?”
Jill: “What is your proof?”
Bill: “No one has been able to prove that people do not have psychic powers.”
“You cannot prove that God does not exist, so He does.”
“College students spend four years of their lives and thousands of their parents’ dollars trying to get as little as possible out of their college education, provided only that they get their coveted diplomas.”
“Aliens don’t exist because no one has ever proven that they do.” (This doesn’t mean that people shouldn’t be skeptical about extraterrestrials because of the lack of evidence. This is a fallacy because the author is claiming that the lack of evidence is proof that they do not exist.)
“Of course God exists. Has anyone ever proven otherwise?”
“Of course pink elephants inhabit Mars. We don’t see them because they blend in. Can you prove they don’t?”
“Of course Santa Claus exists. No one has ever proved, to my knowledge, that Santa Claus does not exist. And if one were to fly to the North Pole and say: Well, look, there’s no toy factory there. A believer could argue: Well, Santa Claus knew you were coming and moved his operations to the South Pole. So you fly down to the South Pole. No Santa Claus factory, toy factory there. So the believer would say: Oh, he moved it back up to the North Pole.”
“Of course leprechauns/ghosts/yellow polka-dotted aliens exist. Has anyone ever proven otherwise?”
“Prove there’s no global conspiracy! The fact that there is no evidence is just proof that it exists! They wouldn’t let you see the evidence!”
“Prove that aliens couldn’t have built the pyramids!”
“There is no evidence for God, so there is no God.” (This statement requires burden of proof. This is not the same thing as, “There is not enough evidence for God, so I do not believe in one” where the claim is that the evidence is not strong enough.)