Cautionary words about poetry from an idiosyncratic and surprising critic and poet. Hollander, usually regarded as a conservative observer of things poetic, both lives up to his reputation and defies it willingly in this essay collection. The Yale professor (and Bollingen Prize and MacArthur fellowship winner) predictably decries, for example, the dominance of creative-writing programs in contemporary America, blaming them in part for the rise of underachieving free verse and for an oversupply of poets who may not deserve the name. ``Free verse . . . is very easy to write if you don't know how,'' he comments, convinced that many self-styled poets don't. ``Good poets know how,'' he notes--as if we couldn't figure that out for ourselves. At his best, Hollander abandons contempt and complaint in favor of real eloquence and mindfulness. For instance, his essays about poets May Swenson and Elizabeth Bishop are models of insight and stylistic clarity and tact. Anyone interested in poetry or criticism must read them. Hollander on Swenson: ``Let words play with each other and they will do the imagination's work. As she herself observed in the preface to a selection of her poems that she'd made for children and that highlights the matter of puzzle and riddle in all poetry: `Notice how a poet's games are called his ``works''--and how the ``work'' you do to solve a poem is really play. . . .' Very, very good poetry does indeed make temporary poets of its readers, just as the inventiveness of poetry is itself so often a kind of interpretation.'' Hollander's comparisons and contrasts among poets are often beguiling, as in his consideration of Edgar Lee Masters, Robert Louis Stevenson, and the relationship between poetry and dreaming. His imagination is unpredictable and stimulating, especially when he does not assume too much about his audience's familiarity with, or views on, poetry. He smites, he laments, but he also enlightens.