First principle foundationalist system of philosophy. He used the "method of doubt", now called Cartesian doubt, to systematically doubt everything he could possibly doubt, until he was left with what he saw as purely indubitable truths. Using these self-evident propositions as his axioms, or foundations, he went on to deduce his entire body of knowledge from them. The foundations are also called "a priori" truths. His most famous proposition is "Je pense, donc je suis." ("I think, therefore I am", or "Cogito ergo sum") Descartes describes the concept of a first principle in the following excerpt from the preface to the "Principles
Mr. Cogito collection published in Hebert's lifetime. Surprisingly religious, it contains 5 more texts with Mr. Cogito's name in the title. These are: "Pan Cogito a Małe Zwierzątko ("Mr. Cogito and a Small Animal"), "Pan Cogito. Aktualna pozycja duszy" ("Mr. Cogito. The Current Position of the Soul"), "Pan Cogito. Ars longa" ("Mr. Cogito. Ars Longa"), "Pan Cogito. Lekcja kaligrafii" ("Mr. Cogito. A Calligraphy Lesson"), "Zaświaty Pana Cogito" ("The Underworld of Mr. Cogito"). On one hand, they still show Mr. Cogito as willing to change the world around him, but, on the other, they express a final resignation to his fate. Mr. Cogito