In
metaphysics, a
universal is what particular things have in common, namely characteristics or qualities. In other words, universals are repeatable or recurrent entities that can be instantiated or exemplified by many particular things. For example, suppose there are two chairs in a room, each of which is green. These two chairs both share the quality of greenness or the quality of being green. Metaphysicians call this quality that they share a "universal", because it can be instantiated or exemplified by many particular things. There are three major kinds of qualities or characterisitcs:
types or kinds (e.g. mammal),
properties (e.g. short, strong), and
relations (e.g. father of, next to). These are all different types of universal.
The noun "universal" contrasts with "individual", while the adjective "universal" contrasts with "particular". Paradigmatically, universals are abstract (e.g. humanity), whereas particulars are concrete (e.g. the desk in the Oval Office). However, universals are not necessarily abstract and particulars are not necessarily concrete. For example, one might hold that numbers are particular yet abstract objects. Likewise, some philosophies, such as those of Hegel and British idealists influenced by him, speak of concrete universals.
Most do not consider classes to be universals, although some prominent philosophers do, such as John Bigelow.
Problem of universals
The problem of universals is an ancient problem in metaphysics whether universals exist. The problem arises from attempts to account for the phenomenon of similarity or attribute agreement among things. For example, live
grass and
Granny Smith apples are similar or agree in attribute, namely in having the attribute of greenness. The issue is how to account for this sort of agreement in attribute among things. There are two main positions on the issue:
realism and
nominalism (sometimes simply called "anti-realism" about universals). Realists posit the existence of universals to account for attribute agreement. Nominalists deny that universals exist, claiming that they are not necessary to explain attribute agreement. Complications which arise include the implications of language use and the complexity of relating language to
ontology.
Particular
A universal may have instances, known as its
particulars. For example, the type
dog (or
doghood) is a universal, as are the property
red (or
redness) and the relation
betweenness (or
being between). Any particular dog, red thing, or object that is between other things is not a universal, however, but is an
instance of a universal. That is, a universal type (
doghood), property (
redness), or relation (
betweenness)
inheres in a particular object (a specific dog, red thing, or object between other things).
Platonic idealism
Platonic realism holds universals to be the
referents of general terms, such as the
abstract, nonphysical entities to which words like "doghood", "redness", and "betweenness" refer. Particulars are the referents of proper names, like "Fido", or of definite descriptions that identify single objects, like the phrase, "that apple on the table". Other metaphysical theories may use the terminology of universals to describe physical entities. Plato's examples of universals included mathematical and geometrical ideas such as a circle and natural numbers as universals. Plato referred to the perfect circle as the
form or blueprint for all copies and for the word definition of the circle.
Ness-Ity-Hood Principle
The
Ness-Ity-Hood Principle is used mainly by English-speaking philosophers to generate convenient, concise names for universals or
properties. According to the Ness-Ity-Hood Principle, a name for any universal may be formed by taking the name of the
predicate and adding "ness", "ity", or "hood". For example, the universal that is distinctive of left-handers may be formed by taking the predicate "left-handed" and adding "ness", which yields the name "left-handedness". The principle is most helpful in cases where there is not an established or standard name of the universal in ordinary English usage: What is the name of the universal distinctive of chairs? "Chair" in English is used not only as a subject (as in "The chair is broken"), but also as a predicate (as in "That is a chair"). So to generate a name for the universal distinctive of chairs, take the predicate "chair" and add "ness", which yields "chairness". (Though it is clear that "chairity" would not work, it is arguable that "chairhood" is preferable to "chairness". It is important to see that the Ness-Ity-Hood Principle offers no way of adjudicating such controversies.)
See also
Notes
References and further reading
- Armstrong, David (1989). Universals, Westview Press.
- Feldman, Fred (2005). "The Open Question Argument: What It Isn't; and What It Is", Philosophical Issues 15, Normativity.

- Loux, Michael J. (1998). Metaphysics: A Contemporary Introduction, N.Y.: Routledge.
- Loux, Michael J. (2001). "The Problem of Universals" in Metaphysics: Contemporary Readings, Michael J. Loux (ed.), N.Y.: Routledge, pp. 3-13.
- MacLeod, M. & Rubenstein, E. (2006). "Universals", The Internet Encyclopedia of Philosophy, J. Fieser & B. Dowden (eds.). (link)
- Price, H. H. (1953). "Universals and Resemblance", Ch. 1 of Thinking and Experience, Hutchinson's University Library.
- Quine, W. V. O. (1961). "On What There is," in From a Logical Point of View, 2nd/ed. N.Y: Harper and Row.
- Rodriguez-Pereyra, Gonzalo (2008). "Nominalism in Metaphysics", The Stanford Encyclopedia of Philosophy, Edward N. Zalta (ed.). (link)
- Russell, Bertrand (1912). "The World of Universals," in The Problems of Philosophy, Oxford University Press.
- Swoyer, Chris (2000). "Properties", The Stanford Encyclopedia of Philosophy, Edward N. Zalta (ed.). (link)
- Williams, D. C. (1953). "On the Elements of Being", Review of Metaphysics, vol. 17.