Final answer:
Antonio is sad in 'The Merchant of Venice,' Act 1, Scene 1 because he has a sense of melancholy and is unable to pinpoint the exact reason behind his sadness. This sets the stage for the conflicts that arise later on in the play.
Step-by-step explanation:
Antonio is sad in 'The Merchant of Venice,' Act 1, Scene 1 because he has a sense of melancholy and he cannot pinpoint the exact reason behind his sadness. This is evident when his friend Bassanio questions him about his sadness and Antonio replies, 'I know not why I am so sad.' Despite his extensive wealth and popularity, Antonio feels a deep sadness that he is unable to shake off.
One possible interpretation for Antonio's sadness is that he is in love with Bassanio, although the play does not explicitly state this. Another interpretation could be that he is troubled by the state of his business ventures and is worried about potential losses. It is also worth noting that Antonio's melancholic nature contributes to the overall tone of the play and sets the stage for the conflicts that arise later on.