Pronunciation: ' kä-gi- ˌ t ō , ' k ō -, ' kä-ji-
Function: noun
Etymology: New Latin cogito, ergo sum, literally, I think, therefore I am, principle stated by René Descartes
Date: 1838
1 : the philosophic principle that one's existence is demonstrated by the fact that one thinks
2 : the intellectual processes of the self or ego