praedicabilis, that which may be stated or affirmed, sometimes called quinque voces or five words) is, in scholastic logic, a term applied to a classification of the possible relations in which a predicate may stand to its subject.
The list given by the scholastics and generally adopted by modern logicians is based on development of the original fourfold classification given by Aristotle (Topics, a iv.
The scholastic classification, obtained from Boethius's Latin version of Porphyry's Isagoge, modified Aristotle's by substituting species (eidos) and difference (diaphora) for definition.
As has been said, the Porphyrian scheme classifies universals as predicates of individuals and thus involves the difficulties which gave rise to the controversy between realism and nominalism.
Its predicate is not convertible with its subject, nor is it part of the definition; accordingly, it expresses only an accidental characteristic of man.