Cogito, ergo sum (See CSMK III 159, 161.) Another predecessor was Avicenna's "Floating Man" thought experiment on human self-awareness and self-consciousness. The 8th century Hindu philosopher Adi Shankara wrote in a similar fashion, No one thinks, 'I am not', arguing that one's existence cannot be doubted, as there must be someone there to doubt. The central idea of "cogito, ergo sum" is also the topic of Mandukya Upanishad. Spanish philosopher Gómez Pereira in his 1554 work "De Inmortalitate Animae", published in 1749, wrote ""nosco me aliquid noscere, & quidquid noscit, est, ergo ego sum"" ("I know that I know something, anyone who knows
Mr. Cogito Departure"). Two Cogito-related texts may be found there. The first one, dedicated to Władysław Walczykiewicz, is entitled "From Mr. Cogito on the Set Topic: Friends Depart" and bears the weight of nostalgic memories of the old times and companions gone. The second poem – "The Calendars of Mr. Cogito" – has a similar atmosphere. Written for Zbigniew Zapasiewicz, it mentions the feelings accompanying Mr. Cogito, who flicks through his old pocket calendars and finds the forgotten names and notes, covered with the mist of time. "Epilogue of the Storm" was released in 1998 and happened to be the last poetry