The unity of the block of cheese is circumstantial, but nonetheless we define a piece of cheese defined on the presence of actual matter. The article goes to so

The unity of the block of cheese is circumstantial, but nonetheless we define a piece of cheese defined on the presence of actual matter. The article goes to some trouble to devise a definition of holes that's also based on matter rather than its absence. But only a strict materialist would feel the need to do that, assuming they didn't want to outright deny existence to holes.