That there ever was such a law that allowed a man to beat his wife so long as the stick he used was no bigger than his thumb is my candidate for the second oldest urban legend still in circulation. The story has been going around for centuries, and every time it comes up in a court of law, somebody tries to find the prescedent, and there is none.
In any case, the origins of the phrase are uncertain, and every etymologist has a different theory about which profession it came from. Phooey. Nobody’s got a definitive answer. But we do know that the association between this phrase and the legal myth above started in the seventies, and is spurious.
I found something like this in the chapter “Loony Laws,” in Dick Hyman’s book Cockeyed Americana. Under the heading for Alabama, Hyman wrote that ‘since a husband is responsible for his wife’s conduct, he is permitted to chastise her with a stick no bigger around than the thumb. Nothing is said about the length of the stick.’ However, I found a decision in the 162nd volume of the Reports of the Alabama State Supreme Court, circa 1943. In the decision: “A man has no more legal right to assault his wife than [does] anyone else.”
It would have been better had Hyman given documentation for this.
<< It would have been better had Hyman given documentation for this. >>
Yeah, twould be better if LOTS of the people citing ULs that “everyone knows” would actually give documentation. Sigh. On the other hand, then we’d never have stuff to debunk!
Keeping in mind the meaning the phrase “rule of thumb” has, I can’t possibly see how the right hand rule could possibly have led to it. Since its meaning deals with aproximation, I think it is far more likely that its origins are based in people aproximating distances using their thumbs. When you use the right hand rule in physics, you know ahead of time that the magnetic field from the wire is not going to be 10 degrees off of perpendicular. You just need to know if it’s clockwise or counterclockwise.
It’s funny that this a subject covered by “The Master” this week. I just saw a “Fact” on CMT (Country Music Television) not that I watch CMT regularly, I just saw a cute blonde and quit channel surfing for a second. It said the whole thing about the rule of thumb and the wife beating farce.
I’m not sure what distinction you’re making here - perhaps an example would clarify. A “rule of thumb” is commonly used as an approximate guide which applies to a wide variety of circumstances. I read a book (well, scanned a book) called “Rules Of Thumb” a few years ago. It was just page after page of stuff like “The distance between an alligator’s eyes, in inches, is equal to its length, in feet.” And “In any airplane, 25% of its cost is in the engine(s).”
These are rules of thumb.
This message thread seems to be two conversations - one is the right hand rule, which I can’t see how there could even possibly be related to rule of thumb, and then there’s the other conversation about rules of thumb.
The French word for “inch” and “thumb” is the same word – “pouce”.
I grew up in a francophone community. I also liked to build stuff as a kid and was always told that, in a pinch, you could “use your thumb to measure an inch”. (Whereupon, it would be noticed that as a little girl, I had very small hands, and the follow up would be “er, never mind…”).
We make measurements in “hands”, and we standardly buy rules that are one “foot” long, so I never questioned the notion that a “rule of thumb” simply meant a “measure of inches.”
(Wondering now why we don’t say “legs” rather than “yards”?..)
In Danish, too: Inch is “tomme” and thumb is “tommelfinger”. Oh, and “rule of thumb” translates into “tommelfingerregel”. I’ll have to find out how old that word is…
The examples continue through successive years without any reference made to beating wives or measuring sticks. There are several references to using experience as a gauge for practical applications. None of the quotations provided indicate ant connection to physics or math.