Discourse on the Method which I did not clearly know to be such." This method of pro-foundational skepticism is considered to be the start of modern philosophy. Discourse on the Method Discourse on the Method of Rightly Conducting One's Reason and of Seeking Truth in the Sciences () is a philosophical and autobiographical treatise published by René Descartes in 1637. It is best known as the source of the famous quotation ""Je pense, donc je suis"" (English: "I think, therefore I am", or "I am thinking, therefore I exist"), which occurs in Part IV of the work. The similar Latin statement, "Cogito, ergo sum",
Cogito, ergo sum for thought". In other words, "the only claim that is indubitable here is the agent-independent claim that there is cognitive activity present". The objection, as presented by Georg Lichtenberg, is that rather than supposing an entity that is thinking, Descartes should have said: "thinking is occurring." That is, whatever the force of the "cogito", Descartes draws too much from it; the existence of a thinking thing, the reference of the "I," is more than the "cogito" can justify. Friedrich Nietzsche criticized the phrase in that it presupposes that there is an "I", that there is such an activity as "thinking",