 Pluralists about mass expressions differ most markedly from sum and set theorists as follows. The set theorist would take ‘the water in Merrihew’s cup’ to refer to the set of water molecules in his cup, and the sum theorist would take it to refer to a fusion. These are both particular entities. But, for the Pluralist, the water is not a particular thing—it is many things. For example, the account that Nicolas recommends