# Appeal to ignorance

*Also called: Argumentum ad ignorantiam*

- **Cluster:** Burden and ignorance — Not knowing treated as knowing
- **Page:** https://fallacy.wiki/fallacy/appeal-ignorance/
- **In Arabic:** https://fallacy.wiki/ar/fallacy/appeal-ignorance.md
- **Licence:** CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/

## What it is

Taking the lack of disproof as proof, or the lack of proof as disproof.

## In the wild

> No one has disproven it, so it is true.

## How to answer it

Point out that not knowing is a third option, alongside true and false.

## Origin and naming

From the Latin 'argumentum ad ignorantiam', 'argument to ignorance', where 'ignorance' means a lack of contrary evidence rather than stupidity. The term was likely coined by John Locke in the late 17th century. It thrives wherever the record is silent: McCarthyism treated an empty file as proof of guilt.

## More places it shows up

- Management has never proven the new tracking software is secure, so let's assume it's fine.
- There's no evidence that this supplement causes harm, which makes it safe to take daily.
- My uncle smoked for forty years and no doctor ever proved cigarettes caused his cough, so the link is invented.
- Nobody on the team has shown our release schedule is unrealistic, so it stays as is.

## How to spot it

- Notice when silence or a missing record is presented as positive evidence.
- Notice when 'you can't prove otherwise' is doing the work of 'here is my proof'.
- Notice when the argument ends exactly where the evidence should begin.

## Nearby

- [Shifting the burden of proof](https://fallacy.wiki/fallacy/burden-shift.md)
- [Argument from silence](https://fallacy.wiki/fallacy/argument-from-silence.md)
- [Unfalsifiability](https://fallacy.wiki/fallacy/unfalsifiability.md)
- [Argument from incredulity](https://fallacy.wiki/fallacy/incredulity.md)

## Read more

- [Wikipedia](https://en.wikipedia.org/wiki/Argument_from_ignorance)
- [Fallacy Files](https://fallacyfiles.org/ignorant.html)

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From fallacy.wiki — a bilingual field guide to 91 logical fallacies, published by phi holdings. Licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/): reuse freely with attribution to fallacy.wiki.