Hypostatic Abstraction is a formal operation that transforms a predicate into a relation. It takes an element of information, as expressed in a proposition X is Y, and conceives its information to consist in the relation between that subject and another subject, as expressed in the proposition X has Y-ness. The existence of the abstract subject Y-ness consists solely in the truth of those propositions that contain the concrete predicate Y. This article actually focus on “subject, y-ness, y, proposition, expressed”.