Scholarship on Aristotle’s theory of visual perception has traditionally held that Aristotle had a single, static, conception of light and that he believed that illumination occurred prior to and independent of the actions of colours. I contend that this view precludes the medium from becoming actually transparent, thus making vision impossible. I here offer an alternative to the traditional interpretation, using contemporary conceptual tools to make good philosophical sense of Aristotle’s position. I call my view the ‘ecological’ interpretation. It postulates (...) two conceptions of light: non-visible mobile propagated light and visible static illumination produced by the interaction of propagated light with the environment’s coloured textured surfaces. I argue that these contemporary conceptual tools can find a foothold in and consistently enrich Aristotle’s extant position and that, with their aid, we can restore coherence to his theories of light and vision. (shrink)

These are the commentaries (or notes) for Aristotle's Metaphysics V (Delta) 18-30. This file must be read together with the translation into Portuguese, which has been published as a different item, with a different DOI. In the Introduction, I discuss many issues about Aristotle's jargon, Aristotle's style and Aristotle's awareness of many philosophical problems that nowadays we locate within the branch Philosophy of Language.