Archibald MacLeish - Ars Poetica

A poem should be palpable and mute
As a globed fruit

Dumb
As old medallions to the thumb

Silent as the sleeve-worn stone
Of casement ledges where the moss has grown -

A poem should be wordless
As the flight of birds

A poem should be motionless in time
As the moon climbs

Leaving, as the moon releases
Twig by twig the night-entangled trees,

Leaving, as the moon behind the winter leaves,
Memory by memory the mind -

A poem should be motionless in time
As the moon climbs

A poem should be equal to:
Not true

For all the history of grief
An empty doorway and a maple leaf

For love
The leaning grasses and two lights above the sea -

A poem should not mean
But be

Archibald MacLeish

http://www.poemhunter.com/poem/ars-poetica-2/