Milosz is a difficult prose writer--not because he uses a jargon or intricate structures or ephemeral imagery, but because his ideas seem not to develop at all. . . until suddenly there's his conclusion: dynamic, whole, learned, modulated, staring you in the face. Here, in Harvard's Norton lectures, Milosz seems at first to meander. He discusses his cousin O. V. de L. Milosz's definition of poetry as ""a passionate pursuit of the Real""; he asks, ""Is non-eschatological poetry possible?""; he proposes that this century's poetry may be based on biology (Darwin, DNA, etc.); he scores classicism for fettering the poet's amorous desire for the world. All interesting--but going where? Polish poetry is then offered as an example of a poetry which, through historical tragedy, has had to overcome alienation, the bohemian/philistine split. And now the argument finally begins to appear: ""The poetic art changes with the amount of background reality embraced by the poet's consciousness."" That Western poetry's background reality consists essentially of ruins, Milosz accepts without sadness; realizing it, he offers, can turn us away from biological illusions of self-sufficiency and back toward history--civilization (failed or not), interdependence, humanity. Milosz, neither Marxist nor reactionary, doesn't easily despair. (It's too bad, he says, that a Nicaragua can't yet learn lessons from a Poland--but historical time is non-parallel, and always will be.) It's dazzling to see what seems like diffidence turning into virile coherence (like Milosz's poetry), to hear a poet speaking of reality without fear or maneuvers or myths. Notable--but demanding and slow to take hold.