There are four kinds of sheets of water:
(1) Flat (uttāna) but deep in appearance (obhāsa);
(2) deep but flat in appearance;
(3) flat und flat in appearance;
(4) deep und deep in appearance.
So, also, there are four classes of people:
handsome in appearance but shallow in mind;
not handsome in appearance but deep in knowledge;
neither handsome nor wise;
both handsome und wise (A.ii.105-6).