This paper derives a formal structure capable of realising the structural content of Leibniz's Monadology — a task that has remained unaccomplished for three centuries. Working from the Principle of First-Classness (FC), the requirement that no mathematical primitive be admitted without internal ground, the paper shows that when FC is applied to a concrete entity of undetermined attribute and undetermined cardinality (the Generic Entity), all conventional mathematical tools collapse. From this catastrophe emerges a hidden symmetry: ontological gender, the qualitative binary between the dispositional modes toHave (feminine) and toBe (masculine). The F/M binary generates a monadological architecture — a finite sea of perspectives, each containing the whole — that realises Leibniz's doctrine with technical precision. The mode of reasoning employed has its earliest known formal precedent in Stoic logic, where candidate syllogisms were tested for "syllogismhood" by reduction to the five indemonstrables. The framework dissolves the containment problem (Russell's paradox) through dispositional structure rather than prohibition, yields the complementary opposition of tempus and situs (formalising Leibniz's Analysis Situs), and is confirmed independently by Gödel's incompleteness theorems. The qualitative binary {F, M} generates a four-element algebra of dyadic types, a universal geometric product, and an emergent scalar line. The paper stands at the intersection of two ancient programmes: Leibniz provides the structural content (monads, combinatorial calculus, characteristica universalis); the Stoics provide the mode of reasoning (right-side, candidate-to-foundation, concerned with Totality/Whole relationships). This is a modified version of the Dispositions of the Quantum Object (DQO) manuscript, reframed for the Leibniz research community and philosophy of mathematics audiences.