How shall we tell an angel
  From another guest?
How, from the common worldly herd,
  One of the blest?

Hint of suppressed halo,
  Rustle of hidden wings,
Wafture of heavenly frankincense,—
  Which of these things?

The old Sphinx smiles so subtly:
  “I give no golden rule,—
Yet would I warn thee, World: treat...