  Now, from the point of view of a nominalist, adoption of modal fictionalism must be coupled with some sort of nominalistically acceptable account of stories, or theories, or representations in general. For accepting something like ‘According to PW there are worlds where there are blue swans’ seems to commit one to PW, and PW is a theory, and so one seems thereby committed to theories. But theories seem to be abstract objects. So the fictionalist nominalist needs a nominalist account of theories. If, for instance, theories are sets of propositions, a nominalist account of sets and propositions would do as a nominalistic account of   theories.[32] 