This text explores the philosophical concept of reactivity and the relationship between a subject's external approach to other beings and their internal integrity. The author distinguishes between true and false beings, positing that true beings possess an interior that is fundamentally inaccessible from the outside. The central problem is whether a subject can react to the internal side of another being without having direct access to it. While this capacity is evident in humans through the ability to anticipate unspoken thoughts, the author considers similar mechanisms in lower organisms, such as insects, and even in subatomic particles. He proposes a hypothesis that even the smallest events may internally adapt to the environment into which they emerge. This internal adaptability could potentially mislead scientists, who might misinterpret it as causal necessity or statistical regularity. The text thus challenges a purely mechanistic interpretation of the world and suggests a deeper interconnection of beings through their internal activity and the capacity to respond to the interiority of others.