What do you call literary works that defy the conventions of ordinary prose or poetry? John D’Agata, in this hefty anthology, prefers to call them “essays” rather than the more popular “creative nonfiction.” And his global selections, spanning centuries, establish an alternate tradition of genre-bending art that transgresses our sense of the essay as a source of information or argument. So don’t expect to find the great English stylists of the 18th and 19th centuries — D’Agata’s playful introductions pooh-pooh the reason and clarity of Johnson, Addison, or Hazlitt. He favors writers who wander, and freely associate, and, most of all, avoid any rhetoric. His survey includes the origins of writing in ancient Sumeria (Ziusudra’s “List”), stops in for a some classical eccentrics (Heraclitus, Theophrastus, Plutarch, and Seneca), and plunders the East for some true wonders of expression, including Sei Shonagon’s unique Pillow Book and Li Shang-yin’s odd collection of observations (“Miscellany”). A few warhorses survive D’Agata’s argumentative history: Montaigne’s quotation-heavy “On Some Verses of Virgil”; Thomas Browne’s meditation on death, “Urn Burial”; and Swift’s exercise in irony, “A Modest Proposal.” But D’Agata’s postmodern agenda finds its best support among his later choices, from the manic visionary poetry of Smart and Blake to the drunken revelries of Baudelaire and Rimbaud to the lunatic rants of Artaud and Pessoa. It’s hard to disagree with D’Agata’s notion that we’ve too readily counted many modern masters as writers of fiction. The dazzling and lyrical prose of Borges, Cortázar, Butor, Lispector, and Duras — all included here — challenge our sense of factual reality. In short, D’Agata’s counter-anthology won’t show up in too many composition classes. But readers looking for a real aesthetic challenge will find much to puzzle over, and enjoy.