From the poem, Dreams, by Thomas Traherne (c. 1637-1674), whose poetry was only first discovered 200 years after his death, and quite by accident, and with new writing being found as recently as 1997.

May all that I can see
Awake, by Night be within me be?
My childhood knew
No Difference, but all was True,
As Real all as what I view:
The World its Self was there: ‘Twas wondrous strange,
That Heav’n and Earth should so their place exchange.
Things terrible did awe
My Soul with Fear:
The Apparitions seem’d as near
As Things could be, and Things they were;
Yet were they all by Fancy in me wrought,
And all their Being founded in a Thought.
O what a Thing is Thought!
Which seems a Dream: yea seemeth Nought,
Yet doth the Mind
Affect as much as what we find
Most near and true! Sure Men are blind,
And can’t the forcible Reality
Of things that Secret are within them see.

Previous poetry posts are here.