The text presents a philosophical analysis of the nature of change, distinguishing between two fundamental types. The first, primary type is internally integrated change, which pertains to the life course or the very being of a true event. The second, derivative type is change facilitated and mediated by the reactivity of a subject within its environment of external realities. The author specifically examines cases where changes exceed the capacity of this reactivity by several orders of magnitude, describing these as inertial processes. A key argument is that pure inertia does not exist in the universe. Instead, all inertia is mediated by the reactivity of subjects at lower levels of existence, which generally follow a specific order and its attraction. In this framework, exceptions to such order are viewed merely as random contingencies. The document thus provides a profound ontological perspective on how physical persistence and change are rooted in the internal dynamics and reactivity of subjects rather than being merely passive mechanical properties of matter.