Pluralism is usually opposed to realism. That's why realists tend to affirm reductionism, even if only the lapsed reductionism of supervenience. It is no accident that postmoderns talk about the different worlds we live in. The realist is bent upon one world with one history, and that is the history for the sciences to tell about it, albeit with different degrees of precision, for different purposes and different points of view. The opposition between realism and pluralism is multiplied when the domains of different theories float about as in the balloon image of the relation of the sciences (Figure 1) and when no combination of fields can together supply a set of descriptions in terms of which at least one baseline history can be told. But the opposition is not necessary.