Editing Theory (section)

== Philosophical==
{{Main|Philosophical theory}}
A theory can be either ''descriptive'' as in science, or ''prescriptive'' ([[normative ethics|normative]]) as in philosophy.<ref>{{cite book |last1=Kneller |first1=George Frederick |title=Introduction to the philosophy of education |date=1964 |publisher=J. Wiley|location=New York |page=93 |url=https://books.google.com/books?id=8OQhAAAAMAAJ&q=editions:UOM39015026974538 |language=en}}</ref> The latter are those whose subject matter consists not of empirical data, but rather of [[idea]]s. At least some of the elementary theorems of a philosophical theory are statements whose truth cannot necessarily be scientifically tested through [[empiricism|empirical observation]].

A field of study is sometimes named a "theory" because its basis is some initial set of assumptions describing the field's approach to the subject. These assumptions are the elementary theorems of the particular theory, and can be thought of as the axioms of that field. Some commonly known examples include [[set theory]] and [[number theory]]; however [[literary theory]], [[critical theory]], and [[music theory]] are also of the same form.

=== Metatheory ===
{{Main|Metatheory}}
One form of philosophical theory is a ''metatheory'' or ''meta-theory''. A metatheory is a theory whose subject matter is some other theory or set of theories. In other words, it is a theory about theories. [[Statement (logic)|Statements]] made in the metatheory about the theory are called [[metatheorem]]s.