A lesbian rule was historically a flexible

mason Mason may refer to: Occupations * Mason, brick mason, or bricklayer, a craftsman who lays bricks to construct brickwork, or who lays any combination of stones, bricks, cinder blocks, or similar pieces * Stone mason, a craftsman in the stone-cut ...

rule Rule or ruling may refer to: Education * Royal University of Law and Economics (RULE), a university in Cambodia Human activity * The exercise of political or personal control by someone with authority or power * Business rule, a rule perta ...

made of lead that could be bent to the curves of a molding, and used to measure or reproduce irregular curves. Lesbian rules were originally constructed of a pliable kind of lead found on the island of Lesbos.

Figurative allusions

The rule is alluded to by Aristotle in his ''

Nicomachean Ethics The ''Nicomachean Ethics'' (; ; grc, Ἠθικὰ Νικομάχεια, ) is Aristotle's best-known work on ethics, the science of the good for human life, which is the goal or end at which all our actions aim. (I§2) The aim of the inquiry is ...

'' (book V, chapter 10) as a metaphor for the importance of flexibility in equitable justice: In the early modern period the term was often used figuratively (as Aristotle had used it) to mean a pliant, flexible and accommodating principle of judgment – sometimes with overtones that were positive, but on other occasions in a more pejorative sense. In his famous letter to the Louvain theologian

Martin Dorp Martin may refer to: Places * Martin City (disambiguation) * Martin County (disambiguation) * Martin Township (disambiguation) Antarctica * Martin Peninsula, Marie Byrd Land * Port Martin, Adelie Land * Point Martin, South Orkney Islands Aus ...

, Thomas More referenced it when reproving Dorp for his attack on Erasmus' ''

In Praise of Folly ''In Praise of Folly'', also translated as ''The Praise of Folly'' ( la, Stultitiae Laus or ), is an essay written in Latin in 1509 by Desiderius Erasmus of Rotterdam and first printed in June 1511. Inspired by previous works of the Italian hum ...

'': "You praise Adriaan for being unbiased, yet you seem to suggest he is no more unbiased than a Lesbian rule, a rule made out of lead which, as Aristotle reminds us, is not always unbiased, since it bends to fit uneven shap