Get out the microscope, because we’re going through this poem line-by-line.
When the blackbird flew out of sight,
It marked the edge
Of one of many circles.
- This section shows how the blackbird influences the way the speaker views the world. The bird passes out of sight when it reaches the horizon, which all of us perceive as a circle that surrounds us in all directions.
- The bird causes the speaker to recognize that the position of the horizon is only a matter of perspective. Each person or creature has his or her own horizon at a particular moment, so the horizon that the blackbird reaches is only one of many. It is the speaker's "circle," but it may not be anyone else's. Similarly, there could be someone far away from the speaker watching the bird enter his field of vision from the horizon.
- Also, the image expresses in concrete terms the idea that you can make infinitely many different kinds of circles using a single point.