Sum: Forty Tales from the Afterlives message of the book is the importance of exploring new ideas beyond the ones that have been traditionally passed down. The title word "Sum" refers to the Latin for "I am," as in "Cogito ergo sum". Like Italo Calvino's "Invisible Cities", "Sum" does not fit entirely into the traditional category of a novel. "Sum" has been called "philosofiction", an "experimental novel", and "a collection of thought experiments". Most of the stories are understood to "posit the afterlife as mirroring life on Earth" The New York Times Book Review called Sum a "delightful, thought-provoking little collection [which] belongs to that category
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