obvert
/əbˈvəːt
/verb [with object] Logic
Alter (a proposition) so as to infer another proposition with a contradictory predicate, e.g. ‘no men are immortal’ to ‘all men are mortal’.An original statement is obverted, the result is converted and that result is obverted again....
- In response to growing concern and upon the advice of a specially appointed committee, the rule was obverted.
Derivatives
obversion
- Obversion always works if it's done right.
- Determine which of the three new moves: conversion, contraposition or obversion has taken place between the premise and conclusion of the argument.
Origin
Early 17th century (in the sense 'turn something until it is facing'): from Latin obvertere, from ob- 'towards' + vertere 'to turn'.