The work opens by distinguishing simple terms from combined propositions, establishing the basic semantic units of thought. It classifies homonymous, synonymous, and paronymous terms to clarify linguistic ambiguity before introducing the fourfold ontological division of entities. The core of the treatise presents the ten exhaustive categories of predicates: Substance, Quantity, Quality, Relation, Where, When, Posture, Having, Activity, and Passivity. Substance is designated as primary because it serves as the ultimate subject for all other attributes while possessing the unique capacity to receive contraries while remaining numerically identical.
Quantity and Quality are analyzed through their internal structures of continuity, graduation, and contrariety. Relation is explored through the mutual dependence of correlatives, though its pervasive nature ultimately stretches across all predicative categories. The text provides a rigorous taxonomy for logical discourse, resolving complex metaphysical relationships into structured, enumerable classes of expression.
