The lover, the lunatic, and the poet are of imagination all compact.

One sees more devil's than vast hell can hold - that is the madman.
The lover 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 form of things unknown
The poet's pen turns them to shapes, and gives to airy nothing
A local habitation, and a name.

                         - William Shakespeare, "A Midsummer Night's Dream"