Analysis of A Sonnet (Two Voices Are There)

Two voices are there: one is of the deep;
It learns the storm-cloud's thunderous melody,
Now roars, now murmurs with the changing sea,
Now bird-like pipes, now closes soft in sleep:
And one is of an old half-witted sheep
Which bleats articulate monotony,
And indicates that two and one are three,
That grass is green, lakes damp, and mountains steep:
And, Wordsworth, both are thine: at certain times
Forth from the heart of thy melodious rhymes,
The form and pressure of high thoughts will burst:
At other times -- good Lord! I'd rather be
Quite unacquainted with the A.B.C.
Than write such hopeless rubbish as thy worst.