mid-15c., cognicioun, "ability to comprehend, mental act or process of knowing," from Latin cognitionem (nominative cognitio) "a getting to know, acquaintance, knowledge," noun of action from past participle stem of cognoscere "to get to know, recognize," from assimilated form of com"together" (see co-) + gnoscere "to know" (from PIE root *gno- "to know"). In 17c. the meaning was extended to include perception and sensation.
*gnō-, Proto-Indo-European root meaning "to know."
It forms all or part of: acknowledge; acquaint; agnostic; anagnorisis; astrognosy; can (v.1) "have power to, be able;" cognition; cognizance; con (n.2) "study;" connoisseur; could; couth; cunning; diagnosis; ennoble; gnome; (n.2) "short, pithy statement of general truth;" gnomic; gnomon; gnosis; gnostic; Gnostic; ignoble; ignorant; ignore; incognito; ken (n.1) "cognizance, intellectual view;" kenning; kith; know; knowledge; narrate; narration; nobility; noble; notice; notify; notion; notorious; physiognomy; prognosis; quaint; recognize; reconnaissance; reconnoiter; uncouth; Zend.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit jna- "know;" Avestan zainti- "knowledge," Old Persian xšnasatiy "he shall know;" Old Church Slavonic znati "recognizes," Russian znat "to know;" Latin gnoscere "get to know," nobilis "known, famous, noble;" Greek gignōskein "to know," gnōtos "known," gnōsis "knowledge, inquiry;" Old Irish gnath "known;" German kennen "to know," Gothic kannjan "to make known."
"process of reasoning, mental process of passing from the cognition of premises to the cognition of the conclusion," 1520s, from Latin ratiocinationem (nominative ratiocinatio) "a reasoning, calm reasoning," noun of action from past-participle stem of ratiocinari "to reckon, compute, calculate; to deliberate, meditate; to reason, argue, infer." This is a compound of ratio "reckoning, calculation," also "judgment, reason" (see ratio) + -cinari, which probably is related to conari "to endeavor, to try," from PIE *kona-, from root *ken- "to hasten, set oneself in motion" (see deacon).
Most writers make ratiocination synonymous with reasoning. J.S. Mill and others hold that the word is usually limited to necessary reasoning. [Century Dictionary]
ancient Greek colony in Libya; the name is of unknown origin. Cyrenaic (1640s) typically refers to the philosophy ("practical hedonism") of Aristippus of Cyrene (c. 435-c. 356 B.C.E.); as a noun, "a Cyrenaic philosopher," from 1580s.
According to Aristippus, pleasure is the only rational aim, and the relative values of different pleasures are to be determined by their relative intensities and durations. He maintained also that cognition is limited to sensation. [Century Dictionary]
1580s, "pertaining to cognition," with -ive + Latin cognit-, past participle stem of cognoscere "to get to know, recognize," from assimilated form of com "together" (see co-) + gnoscere "to know" (from PIE root *gno- "to know").
Taken over by psychologists and sociologists after c. 1940. Cognitive dissonance "psychological distress cause by holding contradictory beliefs or values" (1957) apparently was coined by U.S. social psychologist Leon Festinger, who developed the concept. Related: Cognitively.