For the Roman historians, no passion is more prominent than fear. Fear for them is perhaps the single most important influence on the behaviour of individuals and states. It is often a negative force, deterring people from courses of action that they might otherwise entertain. But it can sometimes cause activity too. A country may be led to attack its neighbour through fear; fear can decide the outcome of a battle or a siege. Fear of assassination may lead a ruler into tyranny; yet it may be fear that drives the hand of the assassin. When a historian wishes to analyse a situation, or explain a policy, he will very often do so at least partly in terms of fear.

Pity is less central. It probably appears less often than, say, anger or hatred as an explanation for action. Yet it too has an important role to play when, for example, people consider whether defeated opponents should be spared, with the concomitant idea that, if so, they may live to fight again, or, alternatively, may transfer their allegiance to the victor out of gratitude. Here, pity or the absence of pity may be presented as the key that will change the course of history.

Does the portrayal of these emotions in the Roman historians owe anything to philosophy? Many of the chapters in this volume are concerned with philosophical influences on Roman literature, and one might hope to find such connections here. Stoicism, in particular, has a distinctive attitude towards the passions, is certainly important for understanding many Roman writers, and has indeed at times been claimed to have influenced various of the major historians.