 That statements about appearances imply that we at least know enough of reality to say that real things have certain possible predicates, e.g., bent or convergent. To deny this is to be wholly unable to state how things look. […] It is only because we know that our distance from an object affects its apparent size that we can draw a distinction between the size it looks and the size it is. If we forget this we can draw no distinction at all. (Prichard 1906, 225–226)