Solipsism then they must be identical, as in indistinguishable from each other and therefore one and the same thing. Dualists then attempt to identify attributes of mind that are lacked by matter (such as privacy or intentionality) or vice versa (such as having a certain temperature or electrical charge). One notable application of the identity of indiscernibles was by René Descartes in his "Meditations on First Philosophy". Descartes concluded that he could not doubt the existence of "himself" (the famous "cogito ergo sum" argument), but that he "could" doubt the (separate) existence of "his" body. From this, he inferred that the
Mr. Cogito Cogito and Pure Thought"), "Pan Cogito czyta gazetę" ("Mr. Cogito Reads A Newspaper"), "Pan Cogito a ruch myśli" (" Mr. Cogito and the Motion of Thought"), "Domy przedmieścia" ("Houses On The Outskirts Of The City"), "Alienacje Pana Cogito" ("Mr. Cogito's Alienations"), "Pan Cogito obserwuje zmarłego przyjaciela" ("Mr. Cogito Watches a Deceased Friend"), "Późnojesienny wiersz Pana Cogito przeznaczony dla kobiecych pism" ("Mr. Cogito's Late Autumn Poem For Women's Magazines"), "Pan Cogito rozważa różnice między głosem ludzkim a głosem przyrody" ("Mr. Cogito Considers the Difference Between the Human Voice And The Voice of Nature"), "Pan Cogito biada nad małością snów" (Mr. Cogito