What have we stopped noticing?
The things we say, do, and accept without thinking twice.
Look closer where it comes from, what it assumes, and the case for keeping it
A rough, practical guideline.
A popular story says the phrase comes from an old law that let a man beat his wife with a stick no thicker than his thumb.
No such law has ever been found. The phrase is recorded by the mid-1600s, meaning working by practice and guesswork rather than exact measurement. It probably comes from using the thumb as a rough ruler.
A 1782 judge was mocked in a cartoon for supposedly saying it, but no ruling has been found; the link to the phrase dates from 1976. It still circulates in good faith.
A false origin story can still change how a phrase lands for someone who has heard it. Knowing the record lets you respond kindly rather than smugly.
- Rule of thumb · The Phrase Finder
- Rule of thumb · World Wide Words
- Rule of thumb · Wikipedia