Incorrigibility Incorrigibility In philosophy, incorrigibility is a property of a philosophical proposition, which implies that it is necessarily true simply by virtue of being believed. A common example of such a proposition is René Descartes' "cogito ergo sum" ("I think, therefore I am"). Johnathan Harrison has argued that "incorrigible" may be the wrong term, since it seems to imply (by the dictionary definition) a sense that the beliefs cannot be "changed", which isn't actually true. In Harrison's view, the incorrigibility of a proposition actually implies something about the nature of "believing"—for example, that one must exist in order to believe—rather than
Cogito, ergo sum and that "I" know what "thinking" is. He suggested a more appropriate phrase would be "it thinks" wherein the "it" could be an impersonal subject as in the sentence "It is raining." The Danish philosopher Søren Kierkegaard calls the phrase a tautology in his "Concluding Unscientific Postscript". He argues that the "cogito" already presupposes the existence of "I", and therefore concluding with existence is logically trivial. Kierkegaard's argument can be made clearer if one extracts the premise "I think" into the premises "'x' thinks" and "I am that 'x'", where "x" is used as a placeholder in order to disambiguate