This document explores the concept of "reactibility" within the context of considering true beings as events. It posits that foundational philosophical terms require continuous refinement as inquiry progresses. Reactibility is characterized as a specific type of activity through which an active subject responds to the "manifesting" realities encountered in its surroundings. The author emphasizes that these surroundings should not be reduced to conventional spatial constructions or simplified objectifications. Instead, the interaction is more fundamental, as illustrated by the example of the eye reacting to photons rather than merely perceiving "things." This approach challenges traditional object-oriented perspectives and moves toward a more dynamic, event-based understanding of existence and perception. The text underscores the necessity of re-evaluating how subjects engage with the world, suggesting that reactibility is central to the nature of beings as ongoing events.