What is the origin of the saying "Rule of thumb?"?

Question

Moose - It was tempting but I swear I never touched him. I'm not even sure which one you're referring to......

Answer 1

No, it is definitely NOT the "stick thing".

In fact, there is no evidence of this claim until VERY recently, in the 1970s!! Unfortunately, at that time, unwitting feminists who heard the claim were quick to spread it. I'm not saying they made it up, but apparently the IDEA fit so well with their expectations that they just ASSUMED it was true. But they never came up with the evidence.

Several folks have done quite a bit of study of English common law to see if there is any support for the claim. There really isn't.

In fact, "RULE of thumb" does not originally refer to a law at all. Rather "rule" here is used in the sense of "ruler", that is, "measuring device." The thumb has at times been used for approximate measure of an inch (cf. use of foot and forearm to measure things). The whole idea of the expression is something that's a good, rough approximation. When you use something as a "rule of thumb" you treat it as something that is generally true or fairly close.

Here is the first recorded use (and the writer is NOT describing wife beating!):

"What he doth, he doth by rule of Thumb, and not by Art"

(in William Hope’s The Compleat Fencing-Master,1692)

The following article contains more information on the alleged connection of this expression with 'permissible wife beating', showing what little foundation that notion has. For starters, Blackstone's writings never say any such thing! (And notice that, when you read this claim, even when they say that it's in such-and-such a work, they somehow NEVER cite chapter and verse!)
http://www.wordorigins.org/index.php/more/489/

This article cites Blackstone's Commentaries on the Laws of England (1765), in which he mentions that at ONE time (but NOT in Blackstone's own day) a man was permitted to five his wife “modest punishment". It goes on to quote the entire passage in which this appears ... and there is NO mention of the thumb at all!!

One other problem with the legend. The explanation given above (use of the thumb for a rough measure) fits well with the way we use the expression. But the legend does not explain how someone got from a supposed limitation on how thick a stick was allowed to be to the meaning 'general, rough principle'.

Answer 2

Rule of Thumb

Meaning:
A means of estimation made according to a rough and ready practical rule, not based on science or exact measurement.


Origin:
This has been said to derive from the belief that English law allowed a man to beat his wife with a stick so long as it is was no thicker than his thumb. In 1782 Judge Sir Francis Buller is reported as having made this legal ruling. The following year James Gillray published a satirical cartoon attacking Buller and caricaturing him as 'Judge Thumb'. The cartoon shows Buller carrying two bundles of sticks and the caption reads "thumbsticks - for family correction: warranted lawful!"

It seems that Buller was hard done by. He was notoriously harsh in his punishments, but there's no evidence that he ever made the ruling that he is infamous for. Edward Foss, in his authoritative work The The Judges of England, 1870, wrote that, despite a searching investigation, "no substantial evidence has been found that he ever expressed so ungallant an opinion".

It's certainly the case that, although British common law once held that it was legal for a man to chastise his wife in moderation (whatever that meant), the 'rule of thumb' has never been the law in England. Despite the phrase being in common use since the 17th century and appearing many thousands of times in print, there are no printed records that asspciate it with domestic violence until the 1970s. The false stories that assumed the wife-beating law to be true may have been influenced by Gillray's cartoon.

Even if people mistakenly believed that law to exist, there's no reason to connect the legal meaning with the phrase - which has been in circulation since at least 1692, when it appeared in print thus:

Sir W. Hope, Fencing-Master, 1692 - "What he doth, he doth by rule of Thumb, and not by Art."

That makes it clear that the origin refers to one of the numerous ways that thumbs have been used to estimate things - judging the alignment or distance of an object by holding the thumb in one's eye-line, the temperature of brews of beer, measurement using the estimated inch from the joint to the nail, etc. It isn't clear which of these is the precise origin and this joins the whole nine yards as a phrase that probably derives from some form of measurement but which is unlikely ever to be definitively pinned down.

Answer 3

Don't know if this is true but here goes.

In the 1400's a law was set forth that a man was not allowed to beat his wife with a stick thicker than his thumb. Hence we have "the rule of the thumb"

Answer 4

Its belief that English law allowed a man to beat his wife with a stick so long as it is was no thicker than his thumb.

Answer 5

'joan...' - great sense of humor.

It's definitely the 'stick' thing, but what about some huge guy with hands like a gorilla - OY - she had better be careful way back then !!

Brutes, weren't they - now boys, don't gang up on this 62 yrs old geezer - I'm just glad my wife has small fingers !! LOL

Answer 6

Men could beat their wives with a stick no wider than their thumb. what happened....Just kidding just kidding.