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 human personality. The third, "Pan Cogito a perła" ("Mr. Cogito And A Pearl") – an unrhymed narrative of a pearl stuck in Mr. Cogito's shoe, treated as a metaphor of having to face life's adversities. The next poems – "Pan Cogito myśli o powrocie do rodzinnego miasta" ("Mr. Cogito Considers Returning to His Native Town"), "Pan Cogito rozmyśla o cierpieniu" ("Mr. Cogito Meditates on Suffering") and "Przepaść Pana Cogito" ("The Abyss of Mr. Cogito") depict Mr. Cogito confronting various existential dilemmas. Existential problems are a presence throughout the collection, appearing in the following texts: "Pan Cogito a myśl czysta" ("Mr.