a posteriori

ay pos-TEER-ee-OR-eye /ˌeɪ pɒˌstɪər.iˈɔːraɪ/
adjectiveadverbC2GREGMATUPSC
academicphilosophical

Relating to knowledge that proceeds from observation or empirical evidence.

Dependent on physical experience; verified only after gathering real-world data.

The story behind the word. Latin for 'from what comes after'. It signifies reasoning backward from observed physical effects to underlying causes.

Word relationships

  • empirical: Empirical broadly relates to experience; a posteriori explicitly highlights justification after observational proof.
  • a priori: A priori knowledge is derived independently of physical sensory experience.

Commonly confused with

  • posterior: Posterior refers to physical rear placement or coming later in time, not epistemological justification.

Collocations

  • a posteriori knowledge
  • a posteriori justification
  • a posteriori truth

Example sentences

  • "The claim that water freezes at zero degrees Celsius is an a posteriori truth confirmed by experiment." Empirical Philosophy

Memory hook

A POSTERIORI = POST (after) seeing empirical evidence. Known after looking.

When not to use

Do not use to describe hindsight or post-facto rationalizations.

Fun facts

  • Empiricists argue that almost all human knowledge regarding the physical cosmos is strictly a posteriori.
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