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 human personality. The third, "Pan Cogito a perła" ("Mr. Cogito And A Pearl") – an unrhymed narrative of a pearl stuck in Mr. Cogito's shoe, treated as a metaphor of having to face life's adversities. The next poems – "Pan Cogito myśli o powrocie do rodzinnego miasta" ("Mr. Cogito Considers Returning to His Native Town"), "Pan Cogito rozmyśla o cierpieniu" ("Mr. Cogito Meditates on Suffering") and "Przepaść Pana Cogito" ("The Abyss of Mr. Cogito") depict Mr. Cogito confronting various existential dilemmas. Existential problems are a presence throughout the collection, appearing in the following texts: "Pan Cogito a myśl czysta" ("Mr.