I don't remember the context in the book very well, but I remember thinking that the premise was that the speaker here (Lia) was somehow well-grounded in concrete reality, by contrast to the other super-mystical characters in the book -- that she could relate ideas to concrete human experience, while other characters were off in the proverbial cloud-cuckoo land.
Your point about Aristotle is well-taken.
Interestingly, Aristotelian physics would have described down as "the true, appropriate place" for material objects and "up" as the unnatural state, only produced by violence and bound to be corrected by the universe.