This text explores the limitations of sensory perception and provides a critique of sensualism, the philosophical view that prioritizes sensory experience as the primary source of knowledge. The author argues that sensory organs alone cannot offer a sufficient foundation for understanding, as they lack the ability to organize the chaotic influx of stimuli without pre-existing comprehension or intellectual guidance. Through the example of astronomy, the document illustrates how human vision was historically limited until supplemented by technological advancements and mathematical methods. These tools allow scientists to predict the existence of celestial bodies even before they are visually observed. Furthermore, the text highlights that physical constraints, such as the wavelength of light, prevent us from perceiving reality in its entirety. Ultimately, the work concludes that the world is far more complex than what our senses reveal. While senses provide essential raw material, true knowledge requires the active participation of reason. The text ends by questioning the fundamental nature of reason itself.