It is often argued that political protest is legitimate only if it is non-violent, a view often attributed wrongly to Mahatma Gandhi, Martin Luther King, Jr., and/or Henry David Thoreau. When some of the Black Lives Matter protests turned violent, Kling and Mitchell, like many, found themselves wondering if this could be justified. Their book explores the ethical foundations of such wondering and concludes that political violence is sometimes justified and is not always inconsistent with the principles of liberal democracy. The argument against violent acts is that they forestall the possibility of resolving conflicts through communication. The authors counter that violence—they exclude lethal violence—may sometimes be needed to assert the right of an oppressed group to enter into such communication. They ground their argument in a comprehensive survey of contemporary ethical scholarship, particularly but not exclusively by scholars influenced by the work of John Rawls. They also seek a philosophical distinction between revolutionary and non-revolutionary protest, since most people would expect states to suppress violent revolutionary protest with force. The book is conversational in tone and would foster good discussion among undergraduate philosophy students. Recommended. General readers and advanced undergraduates through faculty.