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 Seeks Advice"), "Gra Pana Cogito" ("Mr. Cogito's Game"), "Co myśli Pan Cogito o piekle" ("What Mr. Cogito Thinks About Hell"), "Pan Cogito o postawie wyprostowanej" ("Mr Cogito On The Upright Position"), "Przesłanie Pana Cogito" ("The Message of Mr Cogito"). This poetry collection was published in Paris in 1983. An allusion to the state of martial law imposed in Poland by the Communist junta, it was officially unpublishable in Poland. A few months later an underground edition was published by a clandestine press in Poland, and no legal edition was available until 1992. It includes another twelve poems featuring Mr. Cogito,