William Butler Yeats Quote

Opinion is not worth a rush;
In this altar-piece the knight,
Who grips his long spear so to push
That dragon through the fading light,
Loved the lady; and it's plain
The half-dead dragon was her thought,
That every morning rose again
And dug its claws and shrieked and fought.
Could the impossible come to pass
She would have time to turn her eyes,
Her lover thought, upon the glass
And on the instant would grow wise.

Michael Robartes and the Dancer - Michael Robartes and the Dancer (1921)