a priori

adjective
a pri·​o·​ri | \ˌä-prē-ˈȯr-ē, ˌa-;ˌā-(ˌ)prī-ˈȯr-ˌī, -ˌprē-ˈȯr-ē \

Definition of a priori 

1a : deductive

b : relating to or derived by reasoning from self-evident propositions — compare a posteriori

c : presupposed by experience

2a : being without examination or analysis : presumptive

b : formed or conceived beforehand

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Other Words from a priori

a priori adverb
apriority \-​ˈȯr-​ə-​tē \ noun

Synonyms & Antonyms for a priori

Synonyms

deducible, deductive, derivable, inferable (also inferrible), inferential, reasoned

Antonyms

nondeductive

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Did You Know?

A priori, Latin for "from the former", is traditionally contrasted with a posteriori. The term usually describes lines of reasoning or arguments that proceed from the general to the particular, or from causes to effects. Whereas a posteriori knowledge is knowledge based solely on experience or personal observation, a priori knowledge is knowledge that comes from the power of reasoning based on self-evident truths. So, for example, "Every mother has had a child" is an a priori statement, since it shows simple logical reasoning and isn't a statement of fact about a specific case (such as "This woman is the mother of five children") that the speaker knew about from experience.

Examples of a priori in a Sentence

There's no a priori reason to think your expenses will remain the same in a new city. an a priori argument for the defendant's innocence

Recent Examples on the Web

For anyone with a truly open mind, the a priori case for UFOs as a scientific anomaly is firmly established. Kyle Mizokami, Popular Mechanics, "70 Years and Counting, the UFO Phenomenon Is as Mysterious As Ever," 2 July 2018 The look of the films is something that can’t be determined a priori of the rest of its conception. Ben Sachs, Chicago Reader, "An interview with Lucrecia Martel, Argentina's greatest filmmaker," 16 Apr. 2018 For Kant, reason is universal, infallible and a priori—meaning independent of experience. Yoram Hazony, WSJ, "The Dark Side of the Enlightenment," 6 Apr. 2018 Conclusion There is no problem a priori with the fact that Nunes’s memo is a summary prepared by Republican members of the Intelligence Committee’s professional staff. Andrew C. Mccarthy, National Review, "The Clamor over the Nunes ‘FISA Abuse’ Memo," 25 Jan. 2018 That set of capabilities have to be put in place a priori, and not post facto, on this thing, to be able to say, OK, something happened. WSJ, "Here Come the New EU Rules on Data Privacy," 18 Dec. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'a priori.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of a priori

1652, in the meaning defined at sense 1a

History and Etymology for a priori

Latin, literally, from the former

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Time Traveler for a priori

The first known use of a priori was in 1652

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More Definitions for a priori

a priori

adjective

English Language Learners Definition of a priori

: relating to what can be known through an understanding of how certain things work rather than by observation

More from Merriam-Webster on a priori

Thesaurus: All synonyms and antonyms for a priori

Nglish: Translation of a priori for Spanish Speakers

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