Introduction: Limits to Knowledge? No Easy Answer

On the question before us—are there conditions that call for limiting knowledge in a democracy?—principles of unfettered scientific inquiry and of a free press were more than a half-century ago challenged by the restrictive "need-to-know" policies of the security state. Today we continue the hard intellectual work initiated by our predecessors faced with the unprecedented destructive power of nuclear weaponry, and the self-evident need to place limits on nuclear science to guard against its use by rogue states or terrorist organizations. Scientists and journalists cooperated with democratic governments in establishing and policing those limits. Few of us today question limits on knowledge associated with restricting the spread of weapon's of mass destruction.