The poetry of W. S. Merwin offers an escape from what Whitman called ''the pulling and hauling'' of American life, a scrimshaw poetics of small bafflements shaded by the primal dark. Like most ascetics, Merwin is a seducer: his poems invite submission to a pared-down, essences-only view of the world, suggesting that any other way would be square, or, given Merwin's disdain for the human ''species-ego,'' bad for the planet.