This text comes from The Poetical Works of John Keats, a historical songbook transcribed on Wikisource and reproduced from the pinned revision linked below.
Read me a lesson, Muse, and speak it loud
Upon the top of Nevis, blind in mist!
I look into the chasms, and a shroud
Vaporous doth hide them,—just so much I wist
Mankind do know of hell; I look o'erhead,
And there is sullen mist, even so much
Mankind can tell of heaven; mist is spread
Before the earth, beneath me,—even such,
Even so vague is man's sight of himself!
Here are the craggy stones beneath my feet,—
Thus much I know that, a poor witless elf,
I tread on them,—that all my eye doth meet
Is mist and crag, not only on this height,
But in the world of thought and mental night!