 Monism, along with pluralism and nihilism, must therefore be relativized to both a target and a unit. The underlying reason for this double relativity is that these are theses of numerical predication (‘…is one/many/none’), and all numerical predication is doubly relative in this way: for a target (what is to be counted), and by a unit (how it is to be counted). This is one way to understand the moral of Frege’s (1884: 59) insight: 