Cartesian doubt is the basis for Descartes' statement, ""Cogito ergo sum"" ("I think, therefore I am"). Methodological skepticism is distinguished from philosophical skepticism in that methodological skepticism is an approach that subjects all knowledge claims to scrutiny with the goal of sorting out true from false claims, whereas philosophical skepticism is an approach that questions the possibility of certain knowledge. Cartesian doubt is methodological. Its purpose is to use doubt as a route to certain knowledge by finding those things which could not be doubted. The fallibility of sense data in particular is a subject of Cartesian doubt. There are several interpretations
Fuzzy Ergo Sum Fuzzy Ergo Sum Fuzzy Ergo Sum is a science fiction novel written during 2006-2009 by Wolfgang Diehr as a sequel to H. Beam Piper's Fuzzy trilogy: "Little Fuzzy", "Fuzzy Sapiens", and "Fuzzies and Other People". The trilogy concerns the discovery of a primitive species of small, childlike but sapient furry creatures on Zarathustra, a frontier planet with valuable mineral deposits, and the subsequent conflicts this generates between the Fuzzies, the humans who befriend them, and those who would exploit the Fuzzies and their land. "Fuzzy Ergo Sum" begins shortly after the conclusion of the trilogy, involving characters from those books