I’m still in free verse, written in the blue period after sickness, when I felt I could do nothing else well. On the balance side and on the side of formality, I am told all my lines are lines. I do scores of revisions to make them so. I use iambics often loosened into anapests. I suppose definitions of words in the dictionary can be made to do this – anything can be scanned but not made into decisive lines. (…) How different prose is; sometimes the two mediums refuse to say the same things. I found this lately doing an obituary on Hannah Arendt. Without verse, without philosophy, I found it hard, I was naked without my line-ends.
– Robert Lowell (in a letter to Elizabeth Bishop (April 15, 1976), available in the magnificent, indispensable book Words in Air: The complete Correspondence between Elizabeth Bishop and Robert Lowell (eds. Travisano and Hamilton). You need to read it. You know you do.)