Here, 'ignorance' refers to the absence of evidence to the contrary. By exploiting this gap, speakers manipulate their audience into accepting a claim simply because it remains unchallenged. This fallacy shifts the burden of proof onto the opponent, even though the responsibility to provide evidence should rest with the person making the claim—especially when the claim is extraordinary or implausible.
Appeal to ignorance works because it taps into a natural human discomfort with uncertainty. When faced with incomplete information, people are more likely to fill in the gaps with assumptions or beliefs that feel intuitively correct. This is especially true when a claim aligns with their preexisting biases or fears.
Cognitive biases like confirmation bias
- the cognitive bias that leads individuals to favor information that confirms their existing beliefs while disregarding or discounting evidence that contradicts them.
and availability heuristics - the mental shortcut that relies on the ease of recall—to evaluate likelihood or importance, rather than considering all relevant information objectively.
also play a role. If a claim resonates with what the audience already believes or vividly imagines, they may accept it without demanding evidence. By presenting a lack of disproof as evidence in itself, the speaker capitalizes on the audience’s tendency to mistake the absence of evidence for the presence of truth.
Appeal to ignorance flips the script, challenging opponents to disprove a claim. This rhetorical sleight of hand is particularly powerful when the audience is already predisposed to believe the claim, instead of critically evaluating the evidence (or lack thereof).
For example, a speaker might argue that a political candidate has accepted money from foreign governments because the candidate hasn’t addressed or denied the allegation. This tactic exploits the audience's lack of evidence to the contrary while sidestepping the need to provide any actual proof that any money changed hands. By framing the absence of a denial as validation, the speaker creates the illusion of credibility for the accusation without needing credibility to offer any substantiation.
Exposing the appeal to ignorance can be difficult because it requires the audience to recognize and reject their own assumptions. When people have already accepted a claim based on the absence of disproof, they may resist attempts to shift the burden of proof back to the speaker.
Additionally, this fallacy often thrives in situations where evidence is genuinely unavailable. In the case of a politician claiming that their opponent is corrupt because there’s no evidence proving otherwise, this places the opponent in a defensive position, forcing them to disprove an allegation for which no evidence was ever provided. The impossibility of proving a negative further complicates efforts to disarm this fallacy.
To identify an appeal to ignorance, look for arguments that rely on the absence of evidence rather than its presence. Ask whether the claim shifts the burden of proof onto others without meeting basic standards of evidence. Statements like "Well, I’ve never heard him deny it" or "Nobody has proven me wrong, so..." point to the lack of evidence but fail to provide any themselves.
