Speaking of his own work, Robert Duncan (1919-1987) said: "I make poetry as other men make war or make love or make states or revolutions: to exercise my faculties at large." The Opening of the Field, his first major collection, was originally brought out in 1960; in it, Duncan introduced his "Structures of Rime," the open series he continued in his subsequent collections, Roots and Branches (1964) and Bending the Bow (1968), Ground Work: Before the...