Art and criticism make rather strange bedfellows. A book-critic friend of mine recently noticed that he and his artist wife, both enthusiastic gardeners, played entirely different roles in the vegetable garden behind their house: Her job was to nurture the plants, his to whack anything that ventured a tendril outside its appointed row.

With a version of that couple brawling in his psyche, you wonder how a poet-critic such as Adam Kirsch, whose second collection, “Invasions” (Ivan R. Dee, 80 pages, $15.95), has just been published, manages to get anything onto the page. (Picture the poet coaxing shoots of verse to life as the critic swings his brush ax.) But the poems in “Invasions” suggest that, for Mr. Kirsch, poetry and criticism have settled into a symbiotic relationship.

His first poetry collection, “The Thousand Wells,” appeared in 2002, and won a New Criterion prize for its contribution to the new formalism that has been gaining steam since the 1980s. Since then he has published two books of criticism — “The Wounded Surgeon” (2005) and “The Modern Element” (2008) — and hundreds of book reviews.

At a time when academic criticism has become specialized to the point of irrelevance, it’s easy to appreciate the lighter touch Mr. Kirsch brings to critical prose. A strain of lyricism runs through his essays — writing on Walter Benjamin in the New Yorker, he recalled that “Illuminations,” the collection that introduced the German critic to an American audience, “revealed just a few peaks from the sunken continent of Benjamin’s work” — and he has a knack for the pithy detail that sums up a comparison: “The Hardys,” he once wrote, “were the kind of people that Jane Austen would never have allowed into her parlor.”

But the distinguishing feature of his writing on poetry has been its ongoing appraisal of the modernist movement and its legacy among contemporary poets. Mr. Kirsch insists on seeing the vices of modernism — “an obsession with staying up to date, and a belief that distortion of language is interesting and praiseworthy in its own right” — as the flip side of the virtues of boldness and innovation that brought poets such as Ezra Pound and T.S. Eliot to prominence. He writes in “The Modern Element” that “a good modern poem moves us, and a bad modern poem disgusts us, more intimately and profoundly than their equivalents from previous poetic eras.” At the same time, he refuses to accept the modernists’ assumption that the poetic styles and modes of earlier eras were somehow superseded by their own formal experiments.

Like his criticism, the poems in “Invasions” challenge that notion on a number of fronts. Mr. Kirsch’s is a poetry of ideas that draws as much from the Victorians and the 18th century as from the modernists. He writes in regular metrical forms, embracing the iambic rhythm Pound condemned as tyrannous, and his poetic language values clarity over gratuitous effects. Perhaps most striking is the way even his subject matter implies a continuity between past and present that seems to reject the modernist idea that human character changed at the start of the 20th century.

In “Outlet Mall in Western Massachusetts,” Mr. Kirsch concludes that between “Jonathan Edwards’ lamplit century” and our own, nothing much has changed. “The only difference,” the poem maintains, “is the clearing, paved / In asphalt parking lots and ranks of stores, / Huddled all night in a fluorescent nest / More proof against the dark than any fort.” The “bargain-hunters” trolling the mall for deals are engaging in a ritual of habit not that far removed from the religious rites Edwards’s 18th-century congregation used to distract themselves from the mortal facts of human life the poem calls “the forest closing in.”

Like “Outlet Mall,” the other poems in the first section of “Invasions” explore relationships between the past and present, or between the present and a future in which the lives we’re living now will be the substance of the past. They wonder, for example, whether the Cloisters that John D. Rockefeller built along the Hudson River serves as an adequate recompense for the decades of “pillage and extortion” that made Standard Oil profitable enough to subsidize its construction. And they tend to let the questions stand.

Some of the liveliest writing in the collection comes when Mr. Kirsch reaches even further into the literary past — all the way back to the sixth century — and hauls back a series of songs from Boethius’s “Consolation of Philosophy.” In these translations, some looser than others, Mr. Kirsch recognizes that Boethius is weighty enough on his own and lets some air in at the philosopher’s window by shifting into a more arch mode. Boethius’s critique of fame in Book II, for example, gives Mr. Kirsch occasion to quip about modern celebrities for whom “the height of glamour is to earn / The right to have their sex lives analyzed / In English, Urdu, Greek and Japanese, / Until next year when it’s someone younger’s turn.”

“Invasions” closes with a series of 16-line poems that look at life in an age of terrorism. In “September fifteenth, and the house is full,” Mr. Kirsch remembers a performance of the City Opera on September 15th, 2001, when “Ash drifting north has left a coat so thin / The cladded travertine still glitters white, / And so mild no one coughs to breath it in.” The mildness of the fallout at Lincoln Center, not quite five miles from ground zero, belies the realization Mr. Kirsch comes to when it strikes him that the film dusting the travertine is more substantial than it seems: “What I call ash, but know to be this face, / Snapshotted, Xeroxed, stapled to a pole, / Which every breath I takes helps to erase / And scatter incorporate in a new whole.”

This poem eventually says outright what “Invasions” is always on the brink of saying: The various tremors of lived experience — whether they come in the form of an epiphany at an outlet mall or an epic tragedy like the attack on the World Trade Center — shock us into attention, but what we wake to in those moments is a reality that’s always there. The ash that blanketed Manhattan in the wake of the attacks of September 11, 2001, reminded New Yorkers of the value of all those lives lost. “But what air,” Mr. Kirsch asks, “isn’t filled with old remains?”

The poems that follow make the same point in other terms, scratching history with the touchstones of art or architecture, and weighing our achievements against atrocity. Along the way Mr. Kirsch gives an oblique glimpse of his ambitions for poetry in a poem called “Palgrave’s Golden Treasury.” Setting that popular Victorian anthology — a sampling of 300 years of lyric poetry the modernists later rejected as so much outdated syrup — against the bloody chapters of English history, he both concedes that lyric poetry looks disengaged and holds out hope that it does something useful anyway. The poem paints Palgrave’s brand of poet as a figure almost equally touching and ridiculous, “Someone … always listening to birds, / Thinking of evening or a woman’s name / Trying to get something into words.” And however you take those lines, Mr. Kirsch leaves enough ambivalence in the way he describes the poetry itself — an artifact of sorts, “Which is England, golden now and without blame” — to suggest that lyric poetry has a place in the “criticism of life” Matthew Arnold said literature should be.

In “The Modern Element,” Mr. Kirsch argues that Arnold’s phrase is still the best description of what poetry has to offer. That’s clearly what he’s shooting for in “Invasions,” and in most of these poems he hits the mark. René Wellek once warned that “the union of poet and critic is not necessarily good for either poetry or criticism.” But Adam Kirsch’s career suggests that it can be very good for both.

Mr. Davis teaches English at Yale University.