Lover or Dunce?

From Heine's sequence Songs to Seraphine, translated by Emma Lazarus:

Over all the quiet sea-shore
     Shadowing falls the hour of Hesper;
Through the clouds the moon is breaking,
     And I hear the billows whisper.

"Can that man who wanders yonder
     Be a lover or a dunce?
For he seems so sad and merry,
     Sad and merry both at once."

But the laughing moon looks downward,
     And she speaks, for she doth know it:
"Yes, he is both fool and lover,
     And, to cap it all, a poet!"