Universals

Universals such as humanity, redness, and mass are general entities instantiated by particulars. For example, Trudeau and Obama are particulars that instantiate the universal humanity just as stop signs and strawberries instantiate the universal redness. Universals are often held to occupy one or more of the theoretical roles associated with properties. Among other tasks, they are commonly thought to explain the similarities between distinct particulars and to serve as the meaning of expressions like ‘humanity’ and ‘being red’. Unlike trope theory, which rejects universals in favour of particularized property instances like the redness of this very apple or the humanity of Obama, universals are often described as ‘the one over the many’ as they are shared or had in common by distinct particulars. The division between particulars and universals is of both historical and contemporary significance. On one historically influential usage, nominalism is the thesis that reality is exhaustively particular. It therefore explicitly rejects general entities like universals. On a second and perhaps more contemporary usage, nominalism is the denial that there are any abstract entities such as numbers and propositions. Since universals are usually held to be abstract rather than concrete entities, proponents of universals and nominalists – regardless of how ‘nominalism’ is understood – typically stand opposed. Within contemporary metaphysics, there remains considerable disagreement about the nature of universals including their variety, structure, and the instantiation relation that ties universals to particulars. Note, also, that terminological complications abound in this area with some authors using ‘instantiation’ interchangeably with ‘exemplification’ or ‘characterization’ and others taking talk of ‘properties’, ‘qualities’, or ‘attributes’ to be synonymous with talk of ‘universals’. This latter practice often unhelpfully obscures important distinctions among competing views about properties.