Editing Nominalism (section)

==The problem of universals==

Nominalism arose in reaction to the [[problem of universals]], specifically accounting for the fact that some things are of the same type.  For example, Fluffy and Kitzler are both cats, or, the fact that certain properties are repeatable, such as: the grass, the shirt, and Kermit the Frog are green. One wants to know by virtue of ''what'' are Fluffy and Kitzler both cats, and ''what'' makes the grass, the shirt, and Kermit green.

The [[Platonic realism|Platonist]] answer is that all the green things are green in virtue of the [[existence]] of a universal: a single [[Abstraction|abstract]] thing that, in this case, is a [[part (mathematics)|part]] of all the green things. With respect to the color of the grass, the shirt and Kermit, one of their parts is identical. In this respect, the three parts are literally one. Greenness is repeatable because there is one thing that [[exemplification|manifests]] itself wherever there are green things.

Nominalism denies the existence of universals. The motivation for this flows from several concerns, the first one being where they might exist. [[Plato]] famously held, on one interpretation, that there is a realm of abstract forms or universals apart from the physical world (see [[theory of the forms]]). Particular physical objects merely exemplify or instantiate the universal. But this raises the question: Where is this universal realm?  One possibility is that it is outside space and time. A view sympathetic with this possibility holds that, precisely because some form is immanent in several physical objects, it must also transcend each of those physical objects; in this way, the forms are "transcendent" only insofar as they are "immanent" in many physical objects. In other words, immanence implies transcendence; they are not opposed to one another. (Nor, in this view, would there be a separate "world" or "realm" of forms that is distinct from the physical world, thus shirking much of the worry about where to locate a "universal realm".) However, [[metaphysical naturalism|naturalists]] assert that nothing is outside of space and time. Some [[Neoplatonists]], such as the pagan philosopher [[Plotinus]] and the Christian philosopher [[Augustine of Hippo|Augustine]], imply (anticipating [[conceptualism]]) that universals are contained within the ''mind'' of God. To complicate things, what is the nature of the [[instantiation principle|instantiation]] or [[exemplification]] [[logic of relatives|relation]]?

[[Conceptualism|Conceptualists]] hold a position intermediate between nominalism and [[Philosophical realism|realism]], saying that universals exist only within the [[mind]] and have no external or substantial reality.

[[Moderate realism|Moderate realists]] hold that there is no realm in which universals exist, but rather there universals are located in space and time however they are manifest. Suppose that a universal, for example greenness, is supposed to be a single thing. Nominalists consider it unusual that there could be a single thing that exists in multiple places simultaneously. The realist maintains that all the instances of greenness are held together by the exemplification relation, but that this relation cannot be explained. Additionally, in lexicology there is an argument against color realism, namely the subject of the [[Blue–green distinction in language|blue-green distinction]]. In some languages the equivalent words for blue and green may be [[Colexification|colexified]] (and furthermore there may not be a straightforward translation either – in Japanese "青", which is usually translated as "blue", is sometimes used for words which in English may be considered as "green" (such as green apples).)<ref>{{cite journal |last1=Conlan |first1=Francis |date=January 2003 |title=Searching for the semantic boundaries of the Japanese colour term 'AO' |url=https://www.jbe-platform.com/content/journals/10.1075/aral.26.1.06con |journal=Australian Review of Applied Linguistics|volume=26 |issue=1 |pages=71–86 |doi=10.1075/aral.26.1.06con |access-date=April 17, 2022}}</ref>

Finally, many philosophers prefer simpler [[ontology|ontologies]] populated with only the bare minimum of types of entities, or as [[W. V. O. Quine]] said "They have a taste for 'desert landscapes.'" They try to express everything that they want to explain without using universals such as "catness" or "greenness."