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 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.