Valence is a concept that is increasingly being used in the computational study of narrative texts. We discuss the history of the concept and show that the word has been interpreted in various ways. Then we look at a number of Dutch tools for measuring valence. We use them on sample fragments from a large collection of narrative texts and find only moderate correlations between the valences as established by the various tools. We discuss these differences and how to handle them. We argue that the root cause of the problem is that Computational Literary Studies never properly defined the concept of valence in a narrative context.