Without the specific lines, I can only offer a general explanation of why poets often compare imagination to soaring birds:
* Freedom and boundless potential: Birds are associated with freedom and the ability to travel vast distances. This reflects how imagination allows us to explore limitless possibilities, unbound by physical constraints.
* Elevation and transcendence: Birds flying high above the earth symbolize reaching beyond the ordinary and experiencing something elevated and spiritual. Similarly, imagination allows us to rise above our everyday realities and delve into realms of creativity, wonder, and possibility.
* Heightened perspective: Birds have a unique vantage point, seeing the world from a different perspective. This can represent how imagination grants us new insights and allows us to see things from different angles, leading to deeper understanding.
Once you provide the excerpt, I can analyze the specific context and provide a more precise explanation of why Wheatley made the comparison.