Vice President Joe Biden recounted the myth that “the rule of thumb” was part of a baked-in “white man’s culture” permitting abuse of women with a stick no bigger than his thumb.

Biden spread the idea during a speech at the Biden Courage Awards in New York City on Tuesday night, urging supporters to stand up against the abuse of women.

Biden said:

You all know where the phrase ‘rule of thumb’ means? Where it’s derived from? In English common law, not codification of it, common law, back in the late 1300s, so many women were dying at the hands of their husbands because they were “chattle” like the cattle or the sheep – that the court of common law had to do something about the extent of the deaths, so you know what they said? No man has the right to chastise his woman with a rod thicker than the circumference of his thumb. This is English jurisprudential culture. A white man’s culture. It’s gotta change.

The idea has been debunked as a myth and modern feminist folk etymology.

Author Christina Hoff Sommers debunked the idea as “feminist fiction” in her book Who Stole Feminism. Sommers wrote:

The ‘rule of thumb’, however, turns out to be an excellent example of what may be called a feminist fiction. Is is not to be found in William Blackstone’s treatise on English common law. On the contrary, British law since the 1700s and our American laws predating the Revolution prohibit wife beating, though there have been periods and places in which the prohibition was only indifferently enforced. That the phrase did not even originate in legal practice could have been ascertained by any fact-checker who took the trouble to look it up in the Oxford English Dictionary, which notes that the term has been used metaphorically for at least three hundred years to refer to any method of measurement or technique of estimation derived from experience rather than science.

Biden urged supporters to speak out more against sexual predators and harassers in the workplace, to help change the culture.

“We need more people on every campus, not just on campuses, we need them in joining the workplace in the government, everywhere,” Biden said. “You have an obligation when you see in the workplace, one of your colleagues being assaulted, molested or even just harassed to speak out, to speak up.”

Biden apologized for “getting a little too passionate” about the issue, demanding that people “change the culture” of the country to prevent men from sexually harassing women and men from sexually harassing other men.

“It’s on all of us, not just heroes,” Biden said.