The Unbelievers is a 2013 documentary film that follows Richard Dawkins and Lawrence Krauss as they speak publicly around the globe about the importance of science and reason in the modern world, encouraging others to cast off religious and politically motivated approaches toward what they think to be important current issues. The film includes short statements by influential people and celebrities such as Stephen Hawking, Ayaan Hirsi Ali, Sam Harris, Cameron Diaz, Woody Allen, Penn Jillette, Ian McEwan, and David Silverman. The film received mixed reviews from critics.