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 collection published in Hebert's lifetime. Surprisingly religious, it contains 5 more texts with Mr. Cogito's name in the title. These are: "Pan Cogito a Małe Zwierzątko ("Mr. Cogito and a Small Animal"), "Pan Cogito. Aktualna pozycja duszy" ("Mr. Cogito. The Current Position of the Soul"), "Pan Cogito. Ars longa" ("Mr. Cogito. Ars Longa"), "Pan Cogito. Lekcja kaligrafii" ("Mr. Cogito. A Calligraphy Lesson"), "Zaświaty Pana Cogito" ("The Underworld of Mr. Cogito"). On one hand, they still show Mr. Cogito as willing to change the world around him, but, on the other, they express a final resignation to his fate. Mr. Cogito