to capture the ambivalent ¿ unstable and shadowy ¿ aspects of emotions. A number of studies have taken the categorial distinction between positive and negative emotions for granted, suggesting that negative emotions are especially significant for our psychological experience because they signal difficult situations. For this reason, the editors stress the importance of raising analytical questions about the valence of particular emotions and focussing on the features that make these emotions ambivalent: how ¿ despite their negativity ¿ such emotions may turn out to be positive. This opens up a perspective in which each emotion can be understood as a complex interlacing of negative and positive properties. The collection presents a thoughtful dialogue between philosophy and contemporary scientific research. It offers the reader insight by illuminating the dark side of the emotions.