This page was last edited on 7 Aprilat Not Wonder Woman. While Martin appears to have meant the phrase rule of thumb only as a figure of speech, some feminist writers treated it as a literal reference to an earlier law.
The "Rule of Thumb for Wife-Beating" Hoax
Prosser wrote that there was "probably no truth to the legend" that a husband was allowed to beat his wife "with a stick no thicker than his thumb". Look up rule of thumb in Wiktionary, the free dictionary. Word Myths: For instance, the common-law doctrine had been modified to allow the husband "the right to whip his wife, provided that he used a switch no bigger than his thumb" -- a rule of thumb, so to speak.