In The Signature of Evil, the notion of torture in international law is explored, with the intention of discovering the precise meaning of this most infamous and yet still very prevalent practice. By devouring a wealth of international legal sources, and combining this with personal field research and a look at the historical, philosophical, cultural, political and social background of torture’s use and abolition, this book’s first ambition is to define the term. This leads to an extensive and impressive overview, in which torture’s constituent elements are carefully identified, thoroughly and meticulously scrutinised, and critically evaluated. On the basis of this synthesis and analysis, in which all possible uncertainties, problems and evolutions are highlighted and discussed, a redefinition is proposed, which does not shy away from setting foot on new terrain and trying what might be revolutionary roads. Some thought provoking ideas are suggested, and at times controversial choices are made, but all this is done in order to attain one all-important goal: enhancing torture’s absolute and non-derogable prohibition, and strengthening the international legal framework against unlawful abuse.