Philosopher and author John Gray talks about his latest book, Seven Types of Atheism, with EconTalk host Russ Roberts. Gray argues that progress is an illusion and that most atheisms inherit, unknowingly, a religious belief in progress that is not justified. While Gray concedes that technological know-how and scientific knowledge improve over time, he argues that morality and political systems are cyclical and that there is no reason to be optimistic about the future.