With dry wit and self-effacing good humor, Dyson explains that by heretical he means ideas that go against prevailing dogmas, and that in his self-appointed role as heretic, he is unimpressed by conventional wisdom. In recounting his long relationship with the sciences, he underscores the unpredictability of the future with stories about people whose work helped change the world—just not in the way they thought they would. He makes a case for the need for heretics to help keep our vision of the future open and offers “heresies” on such diverse topics as the United States’ status as “top nation,” global warming, the domestication of biotechnology, and the end of Darwinian evolution.