Otherwise known as

syllogistic logic, and constrasted with

propositional logic and

predicate logic, the form of logic discovered by

Aristotle.

The categorical is primarily the evaluation of

arguments consisting of

syllogisms of three catagorical statements, that is, sentences which begin with one of the quantifers "ALL", "SOME" or "NOT" and which seperate a

subject term and a

predicate term with a

copula ("ARE" or "ARE NOT"). Through the use of

Venn Diagrams or an ancient conceptual tool known as the

square of opposition, the

validity of any such syllogism can be derived from their form alone.