Final answer:
The closing statement by Nick in The Great Gatsby uses a metaphor of boats rowing against a current to symbolize characters' efforts to progress while being drawn back by their inescapable past.
Step-by-step explanation:
The phrase "so we beat on, boats against the current, borne back ceaselessly into the past" comes from the novel The Great Gatsby by F. Scott Fitzgerald and is uttered by the character Nick Carraway.
This line serves as the novel's closing sentence and is a reflection on the central themes of the inevitability of the past, the elusiveness of the American Dream, and the struggle of moving forward while being inexorably pulled back by previous events or desires.
The metaphor of boats moving against a current represents the characters' efforts to achieve their goals, despite being constantly pushed back by their past, much like attempting to row upstream only to be carried downstream by the stronger force of the current.