Subject.
228. The noun clause, in its various uses as subject, object, in apposition, etc., often contains a subjunctive.
The essence of originality is not that it be new.—Carlyle
Apposition or logical subject.
To appreciate the wild and sharp flavors of those October fruits, it is necessary that you be breathing the sharp October or November air.—Thoreau.
Complement.
The first merit, that which admits neither substitute nor equivalent, is, that everything be in its place.—Coleridge.
As sure as Heaven shall rescue me, I have no thought what men they be.—Coleridge.
Some might lament that I were cold.—Shelley.