Interestingly I've seen a few very silly articles on cancelled language from Universities recently with phrases like "Rule of Thumb".
(ref:
Brandeis warns students not to say ‘picnic,’ ‘rule of thumb,’ calling words ‘oppressive’)
en.wikipedia.org
"A modern
folk etymology[10] relates the phrase to domestic violence via an alleged rule under English common law which permitted
wife-beating provided that the implement used was a rod or stick no thicker than a man's thumb.
[6] Wife-beating has been officially outlawed in England and the United States for centuries, but enforcement of the law was inconsistent, and wife-beating did continue. However,
a rule of thumb permitting wife-beating was never codified in law.
[3][11][12]: 15 "
"
19th-century United States[edit]
An 1824 court ruling in
Mississippi stated that a man was entitled to enforce "domestic discipline" by striking his wife with a whip or stick no wider than the judge's thumb. In a later case in
North Carolina (
State v. Rhodes, 1868), the defendant was found to have struck his wife "with a switch about the size of this fingers"; the judge found the man not guilty due to the switch being smaller than a thumb.
[12]: 41 The judgment was upheld by the state supreme court, although the later judge stated:
In 1873, also in North Carolina, the judge in
State v. Oliver ruled, "We assume that the old doctrine that a husband had the right to whip his wife, provided that he used a switch no larger than his thumb, is not the law in North Carolina".
[11][12]: 42 These latter two cases were cited by the legal scholar
Beirne Stedman when he wrote in a 1917 law review article that an "old common law rule" had permitted a husband to use "moderate personal chastisement on his wife" so long as he used "a switch no larger than his thumb".
[7][11]
By the late 19th century, most American states had outlawed wife-beating; some had severe penalties such as
forty lashes or imprisonment for offenders.
[12]: 40 There was a common belief in parts of the United States that a man was permitted to beat his wife with a stick no wider than his thumb; however, this belief was not connected with the phrase
rule of thumb until the 1970s.
[12]: 43–44 "
