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
Cogito and the History of Madness his point of departure for "Cogito and the History of Madness" is Foucault's 1961 book "Folie et déraison". Derrida's paper primarily relies on two sections of Foucault's work, the original 1961 preface in which Foucault makes a number of general comments about the book, setting forth his intentions and methodology, and two and a half pages at the start of the second chapter where Foucault links Descartes to an historical event that silenced madness at the end of the classical age. Foucault's 1961 text was heavily abridged for a popular edition in 1964 that formed the basis for Richard Howard's