War is often seen as both morally repugnant and as a heroic activity conducted in the national interest. This introduction outlines some conditions in which this moral dualism appears and is managed in eighteenth-century Britain. It surveys the financial, social, and cultural pressures that could influence public attitudes to war. Focusing on selected examples, it explores the role of humanitarian feeling in justifying particular acts of violence, in enabling a general, compassionate acquiescence in war, and in encouraging the emergence of anti-war attitudes that eventually led to organised opposition to war.