Why should quantifiers floatulcorner This is the question that this paper sets out to answer. In the past, research concentrated on how the theory should account for the non-constituency of a quantificational determiner and the NP it quantifies over. Successful as they might have been, those theories have little, if anything to offer as an answer to the question why quantifiers would float. Here we sketch a theory that puts the scopal properties of FQs (already observed by Dowty and Brodie, 1984) in the center of their properties. We construct a theory in which FQs are simple scope markers and float when differential scope needs to be marked.