Certainty the fact that he was one of the first to write on the topic and acted as a comparison for the traditional and definitive works of the Western tradition. Descartes' "Meditations on First Philosophy" is a book in which Descartes first discards all belief in things which are not absolutely certain, and then tries to establish what can be known for sure. Although the phrase "Cogito, ergo sum" is often attributed to Descartes' "Meditations on First Philosophy", it is actually put forward in his "Discourse on Method". Due to the implications of inferring the conclusion within the predicate, however, he
Cogito, ergo sum in the former case, and an objective thinker in the latter. He argues, first, that it is impossible to make sense of "there is thinking" without relativizing it to "something." However, this something cannot be Cartesian egos, because it is impossible to differentiate objectively between things just on the basis of the pure content of consciousness. The obvious problem is that, through introspection, or our experience of consciousness, we have no way of moving to conclude the existence of any third-personal fact, to conceive of which would require something above and beyond just the purely subjective contents of the mind.