To possess the virtue of honesty or kindness, it is not enough to act sometimes in honest or kind ways. Virtues, like character traits in general, are standing properties of agents that explain their actions. Over the past decade or so, philosophers have debated whether the findings of experimental social psychology undermine the traditional confidence that people do indeed possess such dispositions. This debate has supposed that dispositions are states that generate a particular kind of output from a particular kind of input. The fragility of a vase, on this view, is the disposition to shatter when struck with a certain amount of force. Likewise, the virtue of compassion is, or includes, a disposition to respond to other people's suffering, or the prospect of it, with actions, or at least thoughts and feelings, that tend towards alleviating or averting that suffering. The disagreement has concerned whether people really can develop dispositions to respond appropriately to such a stimulus irrespective of the fine details of the context in which that stimulus occurs (see Miller, this volume, Chapter 37).

However, there are many virtues and other character traits that are not properly understood in terms of stimulus and response. The virtues of constancy, fidelity and integrity form one cluster of such traits. These traits may be displayed in behaviour in difficult circumstances, but what seems essential to them is not the way in which one responds to any particular kind of situation.