[ ob-vur-zhuhn, -shuhn ]

  1. an act or instance of obverting.

  2. something that is obverted.

  1. Logic. a form of inference in which a negative proposition is obtained from an affirmative, or vice versa, as “None of us is immortal” is obtained by obversion from “All of us are mortal.”

Origin of obversion

1840–50; <Late Latin obversiōn- (stem of obversiō) a turning toward, equivalent to obvers(us) (see obverse) + -iōn--ion

Words Nearby obversion

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use obversion in a sentence

  • Dr. Bain calls this Material obversion because it cannot be practised safely without reference to the matter of the proposition.

  • In this it differs from obversion, Conversion, and Contraposition, each of which stands for one process.

    Logic | Carveth Read
  • Define obversion and Inversion, and apply these processes also to the above three propositions.

    Logic | Carveth Read
  • A further process, known as Contraposition or Conversion by Negation, consists of conversion following on obversion.