Ideas matter, and sometimes they can be dangerous.

With this simple conviction, FOREIGN POLICY asked eight leading thinkers to issue an early warning on the ideas that will be most destructive in the coming years. A few of these ideas have long and sometimes bloody pedigrees. Others are embryonic, nourished by breakthroughs in science and technology. Several are policy ideas whose reverberations are already felt; others are more abstract, but just as pernicious. Yet, as the essays make clear, these dangerous ideas share a vulnerability to insightful critique and open debate.