Plotinos: Complete Works, v. 2 / In Chronological Order, Grouped in Four Periods

by Plotinus

REFUTATION OF ARISTOTLE'S INSISTENCE ON A MEDIUM OF SIGHT.

If a medium of sight exist, it exists only by accident, and in no way contributes to sight.[164] Since opaque and earthy bodies hinder sight, and as we see so much the better as the medium is more subtle, it may be said, indeed, that mediums contribute to sight, or at least, if they do not contribute such thereto, they may be hindrances as slight (as possible); but evidently a medium, however refined, is some sort of an obstacle, however slight.