We all hope for peace. Yet in the face of violence, it often seems the only recourse is more violence. Advocates of non-violence claim it’s not necessary to respond to war in kind, and that responding violently, even in self-defense, just perpetuates the cycle of violence. So how can we practice non-violence under the direct threat of violence? Can non-violent acts be spread to stop aggression and war? And are there times when violence is, in fact, necessary? John and Ken keep the peace with Judith Butler from UC Berkeley, author of The Force of Non-Violence: An Ethico-Political Bind.