Higeuerota, the ultimate symbol of the Ideal, is often portrayed as being other
than earthly (see
).
But here, by being specifically above "rock," it means that the Ideal
is beyond the moral reach of material progress. "Shadows of rock,"
furthermore, subtly conveys the notion that the physical facts on which material
progress is founded are themselves insubstantial.
To me, this sentence is also one of the loveliest painterly descriptions in the novel.