 One place such a notion seems useful is in discussions of coincidence and material constitution. Those who think that a clay statue is distinct from the lump of clay that make it up will claim that certain properties of the statue must supervene on properties of the lump of clay that constitutes it. For example, there could not be two statues that are discernible in shape without the statues being constituted by lumps of clay discernible in shape. For further discussion, see  Section 5.5.