Practise thereon my power of casting light,
And calling substance,—when the light I cast
Breaks into color,—by its proper name
—A truth and yet a falsity: black, white,
Names each bean taken from what lay so close
And threw such tint: pain might mean pain indeed
Seen in the passage past it,—pleasure prove
No mere delusion while I pause to look,—
Though what an idle fancy was that fear
Which overhung and hindered pleasure's hue!