After he has published a "major" collection, a poet can be excused for some time. A few may groan a little, but nobody will long lament if he never approximates that height again. They will think that you were lucky to have been there once. It would be still more rare for a poet, in the span of seven years, to follow two "major" collections with a third. But in his new book, The Snow Poems, that is exactly what A. R. Ammons has done. In Collected Poems: 1951–1971, in Sphere: The Form of a Motion, and in The Snow Poems this prolific poet shows no signs of letting up.

In an age when most poets have pulled in their claws to confront us with mushy, probing soft paws, Ammons comes at us with his talons bared, aiming at the Universal Heart. The man's drive is unique in that...