A Brief Description of Realism and Nominalism
In my writings, and especially in the paper titled "Getting Realistic
about Nominalism," I mention realism and nominalism. Each of the
terms "realism" and "nominalism" has more than one meaning in
philosophy. Here I will
explain, very briefly, the meanings most relevant to that paper.
The most traditional forms of realism and nominalism are realism and nominalism with respect to universals. Universals are items, like properties and relations, that can
belong to (or be exemplified by) more than one object. For
example, the color green is a universal, because more than one object
can be green. For another example, the relation of being north of
is a universal, because more than one pair of objects on Earth can
stand in this relation (with one object north of the other).
Realism with regard to universals is the doctrine that universals
are real items; they really have being of some kind. This means
that the real world is
not just a collection of concrete things, like tables and chairs. Instead, the real world contains universals
(properties, relations, etc.) along with the concrete things.
on the other hand,
states that our talk about universals is only figurative. For
nominalist would claim that when we say "red is a color," we are not
really referring to an item named "red" that has many instances or
examples. Instead, the statement that "red is a color" must be
understood in some other way, as a sort of figure of speech.
with regard to universals, there also is a realism with regard to
abstract entities. This doctrine states that abstract entities
(for example, mathematical entities) are real items. Nominalism with regard to abstract entities states that
talk about abstract entities is only figurative.
explanation of realism and nominalism has been very brief; it does not
capture all the fine points. To get a more complete picture, please
consult an encyclopedia of philosophy or an introductory book covering
this topic. One starting point would be the Armstrong or Russell
references in "Getting Realistic about Nominalism."