# Ad hoc rescue

*Also called: Ad hoc reasoning*

- **Cluster:** Distraction and distortion — Moving the argument somewhere easier to win
- **Page:** https://fallacy.wiki/fallacy/ad-hoc-rescue/
- **In Arabic:** https://fallacy.wiki/ar/fallacy/ad-hoc-rescue.md
- **Licence:** CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/

## What it is

Adding an unsupported excuse after the fact to save a claim that failed.

## In the wild

> The prediction failed because conditions were unusual that day.

## How to answer it

Ask whether the excuse was predicted in advance or invented after the failure.

## Origin and naming

From the Latin 'ad hoc', 'for this (purpose only)' — a fix made up for the occasion. Logicians use 'ad hoc rescue' for a patch added after a claim has failed, invented solely to keep the claim alive.

## More places it shows up

- The horoscope app said I'd have a lucky week and I got a parking ticket instead — the astrologer replied that my rising sign must have interfered.
- A startup's growth forecast missed by half; the founder explains that their kind of company simply can't be measured by ordinary metrics.
- A healer's remedy fails to help the patient, so the healer announces it only works on people who truly believe in it.
- The watchlist said the stock would double in six months; when it fell, the analyst added that 'smart money' had deliberately suppressed it.

## How to spot it

- Notice when the excuse appears only after the failure, never in the original terms.
- Notice when the new assumption has no evidence except that it saves the claim.
- Notice when each failed prediction spawns exactly one new patch, never a reconsideration.

## Nearby

- [Unfalsifiability](https://fallacy.wiki/fallacy/unfalsifiability.md)
- [Moving the goalposts](https://fallacy.wiki/fallacy/moving-goalposts.md)
- [Kettle logic](https://fallacy.wiki/fallacy/kettle-logic.md)

## Read more

- [Internet Encyclopedia of Philosophy](https://iep.utm.edu/fallacy/)

---

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.