modus tollens
/ˌmoʊdəs ˈtɒlenz/
if P then Q; Q is false; therefore P is false
modus tollens in a sentence
“Modus tollens: if it rained, streets are wet; streets are dry; it didn't rain.”
Origin of modus tollens
Latin 'method of denying'
Related Words
syllogism
a form of deductive reasoning with two premises and a conclusion
heuristic
a mental shortcut that enables quick but imperfect judgments
satisficing
accepting a good-enough option rather than seeking the optimal one
transitivity
if A relates to B and B relates to C, then A relates to C
deduction
reasoning from general premises to a logically certain conclusion
induction
inferring general principles from specific observations