A Critical Analysis of Descartes’ Cogito Ergo Sum as the foundation of knowledge

The search for certainty has long shaped philosophy, with skepticism raising doubts about whether true knowledge is possible by exposing the unreliability of the senses and the fallibility of reason. It was in this context that René Descartes formulated his project. This paper examines Descartes’ cogito ergo sum as his response to the skeptical challenge. The task is to show how the cogito functions as an indubitable truth, immune to doubt, and to evaluate whether it can serve as the foundation of knowledge as Descartes intended. The central problem is twofold: whether the cogito can stand as a logically valid certainty, and whether it justifies Descartes’ further principle that all clear and distinct ideas are true. My aim, therefore, is to assess critically whether the cogito provides the secure foundation Descartes claimed, or whether it achieves less than he supposed. The methodology is historical and analytical, situating the cogito within the skeptical tradition, reconstructing Descartes’ reasoning, and weighing its strengths and limits through critical evaluation.