Final answer:
In the poem 'Janet Waking', sleep symbolizes the realm of dreams and the unconscious mind, suggesting that dreams hold valuable insights.
Step-by-step explanation:
Sleep in the poem 'Janet Waking' metaphorically symbolizes the realm of dreams and the unconscious mind. The speaker wonders whether they are truly awake or still dreaming, suggesting that their dreams hold valuable insights. This symbolizes the idea that dreams can provide important messages or truths that can be difficult to access in waking life.