Summa of Philosophy According to the Mind of the Angelic Doctor St. Thomas Aquinas - Metaphysics, Part II, Volume II - Salvatore Maria Roselli

This second volume continues Roselli’s Summa of Philosophy, moving from logic into metaphysics (general ontology), presented within the Thomistic tradition of Thomas Aquinas. It aims to systematically unfold the principles of being as such and the highest structures of reality.

The work begins with the notion of being, treating its primary division into essence and existence, and examining how finite beings participate in act and potency. Roselli then develops the transcendentals—unity, truth, and goodness—showing how these properties follow from being itself and apply analogically to all existing things.

A substantial portion is devoted to causality and the principles of being, including efficient, formal, material, and final causes. He explains how these causes structure the intelligibility of reality and ground scientific explanation within a realist metaphysical framework.

The volume also addresses substance and accident, individuation, and distinction, clarifying how individual beings are constituted and differentiated within creation. Throughout, Roselli emphasizes the objective reality of metaphysical principles and the correspondence between intellect and being.

Maintaining a clear scholastic and pedagogical style, the work presents metaphysics as the central science that underlies all other philosophical disciplines, providing the foundation for natural philosophy, psychology, and theology.