The iconic phrase "I think, therefore I am" ("Cogito, ergo sum") is attributed to the philosopher René Descartes. This statement is foundational in Western philosophy, reflecting Descartes' quest for certainty and truth. It suggests that the very act of thinking is proof of one's existence and consciousness. Descartes wrote this in his work "Meditations on First Philosophy," as he sought to establish a secure foundation for scientific knowledge and philosophy. This principle has influenced various philosophical debates about existence, knowledge, and the nature of the self.