if you have to be sure

One of my favourite poems, introduced to me by the lovely Marie: 

Berryman
by W.S. Merwin

I will tell you what he told me
in the years just after the war
as we then called
the second world war

don't lose your arrogance yet he said
you can do that when you're older
lose it too soon and you may
merely replace it with vanity

just one time he suggested
changing the usual order
of the same words in a line of verse
why point out a thing twice

he suggested I pray to the Muse
get down on my knees and pray
right there in the corner and he
said he meant it literally

it was in the days before the beard
and the drink but he was deep
in tides of his own through which he sailed
chin sideways and head tilted like a tacking sloop

he was far older than the dates allowed for
much older than I was he was in his thirties
he snapped down his nose with an accent
I think he had affected in England

as for publishing he advised me
to paper my wall with rejection slips
his lips and the bones of his long fingers trembled
with the vehemence of his views about poetry

he said the great presence
that permitted everything and transmuted it
in poetry was passion
passion was genius and he praised movement and invention

I had hardly begun to read
I asked how can you ever be sure
that what you write is really
any good at all and he said you can't

you can't you can never be sure
you die without knowing
whether anything you wrote was any good
if you have to be sure don't write