Somehow or other I missed this poem all these years, despite its prominence in anthologies and wide acclaim for its author, Jane Hirshfield. “Each Moment a White Bull Steps Shining into the World” is a dramatic, “big” poem—big in ambition, imagery, and theme. Hirshfield is not content here to search for heaven in a wildflower or angel dust on a vase. Not that there’s anything wrong with such poetic devices, as Hirshfield herself would surely attest. But when her second line launches in on a “strange and frightening creature” that we know from the title is a “white bull,” we…