Eric Thayer/Reuters Nearly a quarter century ago, the libertarian magazine Reason published an essay on civil unrest suffused with an insight that movement conservatism still hasn't grasped. Then-editor Virginia Postrel was writing in the wake of the Los Angeles riots of 1992. "What caused the riots?" she asked. "How do we prevent them from recurring?" She agreed with law-and-order voices of that era that a dearth of conscience and empathy were factors.