A growing tide of extremist actions threaten to destabilize civil societies around the world. It has never been more important to understand extremism, the dictionary definition-a reasonable starting point in a seek out understanding-tells us only that extremism is definitely ‘the quality or condition of being intense.’ With this quantity in the MIT Press Essential Knowledge series, J. M. Berger presents a nuanced intro to extremist movements, explaining what extremism is certainly, how extremist ideologies are about Extremism built, and just why extremism can escalate into assault.

Berger, an expert on extremist actions and terrorism, explains that extremism comes from a perception of ‘us versus them,’ intensified from the conviction which the achievement of ‘us’ is inseparable from hostile functions against ‘them.’ Extremism differs from common unpleasantness-run-of-the-mill hatred and racism-by its sweeping rationalization of the insistence on assault. Berger illustrates his discussion with case research and good examples from all over the world and throughout history, from the damage of Carthage with the Romans-often called ‘the initial genocide’-to the apocalyptic jihadism of Al Qaeda, America’s new ‘alt-right,’ and the anti-Semitic conspiracy system The Protocols from the Elders of Zion.