Aristotle has famously made the claim that having the right emotion at the right time is an essential part of moral virtue. Why might this be the case? I consider five possible relations between emotion and virtue and argue that an adequate answer to this question involves the epistemic status of emotion, that is, whether the perceptual awareness and hence the understanding of the object of emotion is like or unlike the perceptual awareness of an unemotional awareness of the same (...) object. If an emotional awareness does not have a unique character, then it is unlikely that emotions provide an understanding that is different from unemotional states of awareness: they are perhaps little more than “hot-blooded” instances of the same understanding. If, on the other hand, an emotional state involves a perceptual awareness that is unique to the emotion, then emotions are cognitively significant, providing an understanding of the object of the emotion that is absent in a similar but unemotional episode of awareness. I argue the latter and substantiate the claim that emotions are essential to moral virtue because they can be essential to a full understanding of the situations that they involve. In such cases, emotions are not merely a symptom of the possession of an adequate understanding, but are rather necessary for having an adequate understanding. (shrink)