follow Dictionary.com

It’s about time. We are now on Instagram!

obversion

[ob-vur-zhuh n, -shuh n] /ɒbˈvɜr ʒən, -ʃən/
noun
1.
an act or instance of obverting.
2.
something that is obverted.
3.
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
1840-1850
1840-50; < Late Latin obversiōn- (stem of obversiō) a turning toward, equivalent to obvers(us) (see obverse) + -iōn- -ion
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
Encyclopedia Article for obversion

in syllogistic, or traditional, logic, transformation of a categorical proposition (q.v.), or statement, into a new proposition in which (1) the subject term is unchanged, (2) the predicate is replaced by its contradictory, and (3) the quality of the proposition is changed from affirmative to negative or vice versa. Thus the obverse of "Every man is mortal" is "No man is immortal." Because the obverse of any categorical proposition is logically equivalent to it, obversion is a form of immediate inference. See also conversion

Learn more about obversion with a free trial on Britannica.com
Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
Cite This Source

Word of the Day

Difficulty index for obversion

Some English speakers likely know this word

Word Value for obversion

0
0
Scrabble Words With Friends

Nearby words for obversion