NEW YORK - He is 86 years old, his eyesight is failing and much of his recent work reads like a man saying goodbye.

But W.S. Merwin continues to write poems; he cannot help himself.

"I wrote the last one about 10 days ago, it doesn't stop, and I don't know where it comes from," says Merwin, a two-time Pulitzer Prize winner and former U.S. poet laureate widely regarded as among the greatest poets of the past half-century.

"I remember, just over a year ago, after several readings and two red-eye flights, I was absolutely exhausted. But in the middle of the night, I woke up with a line and a half of poetry to write."

Speaking by phone from his house on the island of Maui in Hawaii, Merwin said he hopes to finish at least another book, health permitting, and also discussed his latest collection, "The Moon Before Morning." Like his Pulitzer Prize winner from 2008 "The Shadow of Sirius," its themes are age, time and memory. Phrases such as "this unrepeatable present," "the current music of vanishing" and "the long-gone night pasture" can be found throughout.

In "Relics," he writes of his affinity for worlds that have disappeared.

Before I knew words for it

I loved what was obsolete

crumpled at the foot of the closet

lost in the street

left out in the rain

in its wet story

from another age

"I think I've seen so many things in my lifetime just as they were vanishing, and sometimes I realized it was happening and sometimes I didn't," Merwin says.

Born in New York City and raised in New Jersey and Pennsylvania, Merwin is a Presbyterian minister's son whose earliest memories of language include writing out the sermons of his father. He was composing his own verse while still a boy and was class poet at Princeton University. His first collection, "A Mask for Janus," won the Yale Younger Poets prize in 1951, and by the end of the decade, his friends and acquaintances included Ezra Pound, T.S. Eliot, Sylvia Plath and Robert Lowell.

His style and subject matter would change profoundly, from the classical influences of his early poems to the anti-war themes of the 1960s to the more condensed and philosophical verse of recent years, influenced by his immersion in Buddhism. Throughout, he has been a man of peace - he was a conscientious objector during World War II - a recorder of the past, a believer in nature and a skeptic of humankind. At his Princeton graduation, he read a commencement poem that mourned those who had died in war and explained to the graduation committee that he had "little optimism" about the future.

"I think what we've been doing to the Earth, especially since the dawn of the machine age, is so appalling that I don't know (if) we can turn it back," he says during his interview.

Work these days can be a struggle for Merwin in part because he writes in longhand and has to make the letters large in order to read them. Still, the pictures are clear in his mind and words themselves make him hopeful.

"I think of one of my greatest heroes, (William Butler) Yeats," Merwin said. "He wrote at length - although nothing of Yeats is too long - about old age. He came to it with real anger, as though it was an outrage."

"I think of old age as being a time like the others. It has its revelations of its own that you can't come to any other way. I don't have any of those feelings Yeats had at all. I accept it with a certain amount of curiosity."