C.K. Williams. (Benoit Cortet/Benoit Cortet)

C.K. Williams, a Pulitzer Prize-winning poet, is known for work that stretches the poetic form. His new book, “All At Once,” (Farrar, Straus and Giroux, $25) crosses into prose poetry, which he says allows him to be sometimes more narrative, sometimes more intellectual. During National Poetry Month, he spoke from his home in Princeton, N.J.

I didn’t see a particular theme in this collection — it feels more like an insight i nto how you see the world.

If there’s anything, that would be it. I don’t think of the book as having a theme. I had all these partial poems and partial prose things, and all of a sudden it seemed to become important to finish them all. And then I had a book. That’s sort of a nice surprise.

The section “Catherine’s Laughter” is a beautiful love poem to your wife. What were you after here?

Some of the first pieces are almost 40 years old, from when we first met, and the last one was written the day before I closed down the book. I had started with no particular aim in mind. I just one day began listening to her laugh, and realized that what I heard every day was really unusual. So I wrote it down. And I’d sort of add to it now and again. And there it was. Another surprise.

This is your first collection of prose poems. Why did you turn to this form?

They seem to be using a different part of my aesthetic consciousness. My line poetry is very determined by the music of the language, and this came from a different place. It represented giving up some of the constraints of poetry and allowing other things to happen: some more playful things, some more intellectually analytic, some more directly narrative, some more sociological. One of my big influences is Baudelaire. His prose poems are sort of various and some are little stories the way mine are, and I decided to keep following Baudelaire and see what happened.

You published your first book at 33, and several pieces discuss the struggle you had as a writer early on.

I think all writers struggle, and poetry is its own particular kind of struggle. Although I was 33, I knew that it was the right time — I knew if I had been able to publish a book five years before that, it wouldn’t have been a very good book.

Is it still hard?

Yes. It isn’t the same kind of hard. I don’t have to spend so much time mastering my craft, because I pretty much have that under control. But it’s still hard to find the right inspiration and the right voice and the right music to embody the inspiration. That’s the primary business of the poet: to bring the matter and the music together. The best poetry, when you’re reading it, you hear two voices simultaneously — the voice of the poet and your own voice.

You’ve also written again about aging.

It’s the fact of my life. I’m surprised sometimes I don’t write about it all time. There are two themes I’m amazed that I keep at bay: climate change and aging. Probably close to half the poems I’ve written since this book are openly involved with climate change. It’s the great crisis of our time and it’s the strangest crisis, because it’s being repressed. Aging is in a way an easier thing to talk about because we’ve had a lot of experience with aging, but we haven’t had a lot of experience with destroying our planet.

Are there any advantages to being older?

None. No, there’s one. Having grandchildren. I have three grandchildren, and that’s one of the wonderful parts of my life.

If you could recommend one poet to someone who doesn’t know poetry well, who would you suggest?

Walt Whitman. He really defines what poetry can be after him, not just for Americans but all over the world. Once you read him, you just knew that poetry had to be something other than what you thought it had been.

Carole Burns, the editor of “Off the Page: Writers Talk About Beginnings, Endings, and Everything in Between,” is head of creative writing at the University of Southampton in England.