  How do nominalists answer this question? A popular nominalist theory of properties is so-called Trope Theory, which has been held by Donald Williams (1953), Keith Campbell (1990), and Douglas Ehring (2011) among others. Trope theory does not reject the existence of properties, but takes properties to be certain entities usually called ‘tropes’. Tropes are particulars, in the same sense in which individual people and individual apples are particulars. Thus when there is a scarlet apple the scarletness of the apple is not a universal but a particular scarletness, the scarletness of this apple, which exists exactly where and when this apple is   scarlet.[9]  Such a particular scarletness is a trope. The apple is scarlet not in virtue of instantiating a universal but in virtue of possessing a scarlet trope.