Explain how the pond is a central metaphor for Thoreau and an essential concept in his philosophy.

The pond has long been a symbol for Thoreau's self, reflecting him in its depths. Now, as he awakens, shaking off the sleep which encased and surrounded him, he represents this process in the act of cutting into the ice which surrounds the pond. He compares the pond the hibernating marmot; it too "closes its eyelids and becomes dormant for three months." However, rather than accept this delaying of life, Thoreau struggles against it, metaphorically opening the pond's eyes ­ his own perceptions ­ by cutting into the ice.

Therefore, Thoreau's attempts to study and understand the pond in a way no other townsmen have done before him, represents his ability to look into himself by simultaneously looking into nature. His findings about the pond's depth would surprise and contradict the assumptions of most people, just as his realizations in living at Walden about his own life run counter to common beliefs. The unexplored depths of the pond are also the unexplored depths of his own life that Thoreau went to Walden to study.