A guiding premise of this book is that despite a great deal of academic and popular interest in violence and civil war and the lurid and tragic details associated with them, violence in civil wars remains poorly understood. Extant literature on the subject suffers from a number of pathologies rising from the manner in which violence is conceptualized and the biases brought in either by researchers themselves or by the logistics involved in studying civil war. Specifically, the study of violence in civil war must overcome at least a frequent misconceptualization, referred to here as “madness,” and five common biases: the partisan bias (taking sides), the political bias (equating war with peace), the urban bias (overlooking bottom-top processes), the selection bias (disregarding nonviolence), and the overaggregation bias (working at too high a level of abstraction).