 The philosophical practice of separating what is immediately given to vision by way of sense impression from further psychological or logical acts of perception stems from  antiquity.[3]  In the optical tradition (where “optics” covered the complete science of vision, from physics and physiology to psychology), the medieval Islamic philosopher Ibn al-Haytham (ca. 1030) distinguished what is found in “pure sensation”, the immediate result of stimulating the sense organs, from what depends on recognition, judgment, and reason (Optics, II.3.25). Arguably (Hatfield 2020: 200), he included light, color, and visual direction (a correlate of shape) among the things immediately sensed. The optical tradition as promulgated in the medieval European Latin West provided a framework for the theories of vision of Descartes and Berkeley (Hatfield &amp; Epstein 1979: 371). The distinction between (a) a core of sensation and (b) perception of objects in the world as the result of further psychological processes provided the predominant framework for theorizing about the senses into the twentieth  century.[4]  The proximate background for the arguments about sense data just after 1900 was set by engagement with early modern philosophy and nineteenth-century British philosophy.