This chapter investigates the rationale for having the lexical categories or features mass and count. Some theories make the features be syntactic; others make it be semantic. It is concluded here that none of the standard accounts of their function actually serve the purpose for which they are adopted, and that we should instead remove these features from the lexicon and have lexical nouns be neither +mass nor +count. But on the other hand, if every lexical noun could be characterized by both +mass and +count, then various of the desiderata would be captured. So we conclude that lexical nouns should be neither +mass nor +count, and both +mass and +count. Although this investigation is carried out in English, the moral holds for any ‘number marking’ language. Furthermore, the resulting theory is the one that is naturally congenial to classifier languages, showing a hithertofore unnoticed similarity between the two language classes. (However, languages that are of neither type … such as Dene Su ̨łiné, Yudja, and Karitianan … require some totally distinct vision of a mass-count distinction.)