This text explores the nature of sensory experience and its relationship with perceptiveness and reactivity. The author argues that sensory experience is not merely an experience of sensory organs but is rooted in an understanding of what "sense" or meaning implies. Perceptiveness is presented as a significant invention with various forms, merging at its most primitive levels with reactivity. However, the author emphasizes a fundamental distinction between the two: while a reaction serves as evidence of perception, the absence of a reaction does not necessarily prove a lack of perception. Reactivity in its primordial forms is limited in its ability to differentiate responses, making it difficult to judge the true depth of perceptiveness based solely on external actions. The gap between perceptiveness and reactivity suggests that perception is a more complex and expansive process than simple physiological response. Ultimately, the document suggests that perception involves a situational and perspectival component where not everything potentially perceptible is actually perceived, highlighting the non-identity between internal sensing and external reacting.