I think therefore I am

Syllable breakdown

Dictionary meaning

the foundational philosophical proposition of René Descartes, expressed in Latin as Cogito ergo sum, establishing that the act of doubting one's own existence is itself proof of the existence of a thinking self; Descartes arrived at this formulation through his method of radical doubt — stripping away all beliefs that could possibly be false — and discovering that the one thing that could not be doubted was the experience of doubting itself; the cogito has anchored rationalist philosophy, shaped the Western conception of personal identity as grounded in thought and consciousness, and become the most famous sentence in the history of philosophy