Cogito, ergo sum relying on clarity, distinctiveness, and self-evidence. Baruch Spinoza in ""Principia philosophiae cartesianae"" at its "Prolegomenon" identified "cogito ergo sum" the ""ego sum cogitans"" (I am a thinking being) as the thinking substance with his ontological interpretation. It can also be considered that "Cogito ergo sum" is needed before any living being can go further in life". Although the idea expressed in "cogito, ergo sum" is widely attributed to Descartes, he was not the first to mention it. Plato spoke about the "knowledge of knowledge" (Greek νόησις νοήσεως "nóesis noéseos") and Aristotle explains the idea in full length: But if life
Cogito, ergo sum familiar form of the phrase in his 1641 "Meditations on First Philosophy". The earliest written record of the phrase in Latin is in his 1644 "Principles of Philosophy", where, in a margin note (see below), he provides a clear explanation of his intent: "[W]e cannot doubt of our existence while we doubt". Fuller forms of the phrase are attributable to other authors. The phrase first appeared (in French) in Descartes's 1637 "Discourse on the Method" in the first paragraph of its fourth part: In 1641, Descartes published (in Latin) "Meditations on first philosophy" in which he referred to the proposition,