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 Seeks Advice"), "Gra Pana Cogito" ("Mr. Cogito's Game"), "Co myśli Pan Cogito o piekle" ("What Mr. Cogito Thinks About Hell"), "Pan Cogito o postawie wyprostowanej" ("Mr Cogito On The Upright Position"), "Przesłanie Pana Cogito" ("The Message of Mr Cogito"). This poetry collection was published in Paris in 1983. An allusion to the state of martial law imposed in Poland by the Communist junta, it was officially unpublishable in Poland. A few months later an underground edition was published by a clandestine press in Poland, and no legal edition was available until 1992. It includes another twelve poems featuring Mr. Cogito,