The lunatic, the lover, and the poet

The lunatic, the lover, and the poet
Are of imagination all compact.
One sees more devils than vast hell can hold,
That is, the madman: the lover, all as frantic,
Sees Helen’s beauty in a brow of Egypt:
The poet’s eye, in a fine frenzy rolling,
Doth glance from heaven to earth, from earth to heaven;
And as imagination bodies forth
The forms of things unknown, the poet’s pen
Turns them to shapes, and gives to airy nothing
A local habitation and a name.
Such tricks hath strong imagination,
That if it would but apprehend some joy,
It comprehends some bringer of that joy;
Or in the night, imagining some fear,
How easy is a bush supposed a bear!