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.
—William Shakespeare, from A Midsummer Night’s Dream, Act 5, Scene 2 (Theseus speaking)