SINCE 1828
dictionary
thesaurus

modus tollens

noun
Save Word
modus tol·​lens | \ -ˈtäˌlenz \
plural modi tollentes\ -​(ˌ)täˈlen‧ˌtēz \

Definition of modus tollens

: a mode of reasoning from a hypothetical proposition according to which if the consequent be denied the antecedent is denied (as, if A is true, B is true; but B is false; therefore A is false)

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

History and Etymology for modus tollens

New Latin, removing mode

Learn More About modus tollens

Dictionary Entries Near modus tollens

modus ponens

modus tollens

modus vivendi

See More Nearby Entries 

Statistics for modus tollens

Cite this Entry

“Modus tollens.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/modus%20tollens. Accessed 4 Jul. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

WORD OF THE DAY

Yankee

Listen to the pronunciation of Yankee

See Definitions and Examples »

Test Your Vocabulary

Name That Food

  • a-light
  • Name these cookies!
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
Universal Daily Crossword

A daily challenge for crossword fanatics.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Words at Play
Ask the Editors
Word Games