In this part the basic concepts are discussed. Two features appear and reappear throughout the book. The first is the concept of conflict itself and the issues involved in its definition and analysis; the second is the concept of a social science. Conflict is looked at as a generic process which is involved in all social behaviour. However, it is war and violent political conflict which are central to the analyses of this book, though not to the exclusion of other significant issues in conflict analysis. I approach war from the point of view of a social scientist and argue the legitimacy of this mode of analysis and, indeed, its necessity if we are to be able to have the sort of understanding of it which would help reduce its incidence. The reasons for holding this view are discussed at some length.