The End of Faith: Religion, Terror, and the Future of Reason by Sam Harris is a sharp 2004 polemic that argues religious faith is inherently dangerous because it prioritizes unverified belief over evidence and reason, enabling both historical violence and modern terrorism. Harris contends that even moderate religion shields extremism from criticism and that only a thorough commitment to science, reason, and secular ethics can safeguard civilization.

The book is forceful, lucid, and historically informed, and it helped launch the New Atheism movement, though many readers find its treatment of Islam especially severe and its dismissal of all religious moderation overly absolute.