Mercenary warriors have generally had a bad name over the centuries, and never more so perhaps than in the last third of the twentieth century. My purpose here is to examine both the name and the evaluation. I do this not only because of the considerable intrinsic interest of the topic, but also because I think that such an examination is likely to throw light upon wider issues in the theory of war, and especially upon the ethics of war and the morality of political violence in general. More specifically, closer attention to what is morally distinctive about mercenaries is likely to improve our understanding of the moral status and responsibilities of regular soldiers.

Both the name and the ill repute raise philosophical perplexities. There are underlying puzzles about what we are to understand by the term “mercenary,” and there is a deal of obscurity about the source of the obloquy commonly heaped upon those who bear the name. Not that all evaluations have been negative: the supporters of mercenary soldiery include St. Thomas More, whose wise Utopians would do everything they could to avoid sending their own citizens into battle, and so “most of their fighting is done by mercenaries.” Indeed, mercenaries have been commonly employed in warfare throughout the centuries. To support or defend mercenaries, however, we need to have at least a rough idea of what they are.