In her new volume of prose poem “dialogues,” Reluctant Gravities, Rosmarie Waldrop once again pushes the boundaries and definitions of poetry, prose, gender, relationship, even language itself. Intended as a sequel to The Reproduction of Profiles and Lawn of Excluded Middle, Reluctant Gravities gives the rhetorical “you” addressed in those earlier volumes a voice and response. Some of Waldrop’s concerns are formal. As the author herself says, she “cultivates cuts, discontinuity, leaps, shifts of reference” in an attempt to compensate for the lack of margin, where verse would turn toward the white of the page, toward what is not. Instead, her “gap gardening” tries to place the margin, the emptiness inside the text. Yet the overriding point of the dialogues is determinedly human as the two voices with wit and philosophical playfulness debate aspects of “Aging,” “Depression,” “Desire,” and even ’’The Millennium.”