Cogito, ergo sum though not explicitly as "cogito, ergo sum" in Meditation II: In 1644, Descartes published (in Latin) his "Principles of Philosophy" where the phrase "ego cogito, ergo sum" appears in Part 1, article 7: Descartes's margin note for the above paragraph is: Descartes, in a lesser-known posthumously published work dated as written ca. 1647 and titled ("The Search for Truth by Natural Light"), wrote: The proposition is sometimes given as . This fuller form was penned by the eloquent French literary critic, Antoine Léonard Thomas, in an award-winning 1765 essay in praise of Descartes, where it appeared as In English, this
Cogito, ergo sum of other minds at this point. This is something that has to be thought through by each of us for ourselves, as we follow the course of the meditations. Second, he does not say that his existence is necessary; he says that "if he thinks", then necessarily he exists (see the instantiation principle). Third, this proposition "I am, I exist" is held true not based on a deduction (as mentioned above) or on empirical induction but on the clarity and self-evidence of the proposition. Descartes does not use this first certainty, the "cogito", as a foundation upon which to build