This conclusion presents some closing thoughts on key concepts discussed in the preceding chapters of this book. The book offers intriguing findings about the processes by which controversy and conflict evolve into violence, which many scholars have come to describe as radicalization. It sheds considerable light on the meaning of the concept of radicalization. The book explores the dangers of prediction in this field, which is a salutary caution for all social scientists and policy analysts. The underlying assumption behind the theory of outbidding in extremism, often implicit, is that it is violence, not non-violence, that is valued by the critical public and that thus elicits popular support and arouses enthusiasm. The question of unintended consequences is usually addressed to the actions of states as they confront challengers, but it is also relevant to the actions of oppositional forces. Scholarship has generally neglected the unintended consequences of decisions made by challengers.