is a 1996 non-fiction book by Umberto Eco and Cardinal Carlo Maria Martini.

The book was named one of the Los Angeles Times' "Best Nonfiction Of 2000".

has eight chapters, during which Eco and Cardinal Martini discuss various topics such as religion, belief, abortion, and ethics.

The book's title refers to "the beliefs of those who do not believe in God or religious dogmas".

[4][5] The Los Angeles Times and the Dallas Morning News both gave positive reviews for Belief or Nonbelief?,[6] with the Los Angeles Times calling it a "short but challenging book".