<P> The English phrase rule of thumb refers to a principle with broad application that is not intended to be strictly accurate or reliable for every situation . It refers to an easily learned and easily applied procedure or standard, based on practical experience rather than theory . This usage of the phrase can be traced back to the seventeenth century . </P> <P> A modern folk etymology holds that the phrase derives from the maximum width of a stick allowed for wife - beating under English law; this belief may have originated in a rumored statement by the eighteenth - century judge Sir Francis Buller that a man may beat his wife with a stick no wider than his thumb . The rumor produced numerous jokes and satirical cartoons at Buller's expense; however, there is no record that he made such a statement . </P> <P> The English jurist William Blackstone wrote in his Commentaries on the Laws of England of an "old law" that once allowed "moderate" beatings by husbands, but did not mention thumbs or any specific implements . While wife beating has been officially outlawed for centuries in England and the United States, it continued in practice; several nineteenth - century American court rulings referred to an "ancient doctrine" that the judges believed had allowed husbands to physically punish their wives using implements no thicker than their thumbs . </P>

Where did the saying rule of thumb come from
find me the text answering this question