Was it the proud full sail of his great verse,
Bound for the prize of all too precious you,
That did my ripe thoughts in my brain inhearse,
Making their tomb the womb wherein they grew?
Was it his spirit, by spirits taught to write,
Above a mortal pitch, that struck me dead?
No, neither he, nor his compeers by night
Giving him aid, my verse astonished.
He, nor that affable familiar ghost
Which nightly gulls him with intelligence,
As victors of my silence cannot boast;
I was not sick of any fear from thence:
But when your countenance fill’d up his line,
Then lacked I matter; that enfeebled mine.
In plain English
The speaker asks whether the rival poet's grand and ambitious writing intimidated him into silence. Was it the rival's supernatural gift—aided perhaps by occult spirits—that struck him down and killed his own creative voice? No, the speaker insists. Neither the rival poet nor any ghostly helpers whispering secrets to him at night could have achieved that.
What actually silenced the speaker was something else entirely: when the young man's face and beauty filled up the rival's lines, the speaker had nothing left to write. The young man's attention going elsewhere drained the speaker of his own subject matter, and with it, his power to compose.