What seems to be there, but isn’t?

As Dr. Oliver Sacks explains in Hallucinations, his latest collection of absorbing essays, “Hallucinations, beyond any other waking experience, can excite, bewilder, terrify, or inspire, leading to folklore and the myths (sublime, horrible, creative, and playful) which perhaps no individual and no culture can wholly dispense with.”

Hallucinations, which differ starkly from dreams and imagination, are often associated with wild visions induced by fever, madness or drugs. They come in much greater variety, however, and include hearing voices, music or noises, feeling things or smelling odors—none of which exist. This multitude of illusions has a grand litany of causes, including injury, illness, migraines, trauma, epilepsy and more.

As always, Sacks, the best-selling author of Awakenings and The Man Who Mistook His Wife for a Hat, describes a fascinating cast of patients, starting with a blind, elderly woman named Rosalie, who suddenly began seeing a parade of people in colorful “Eastern” dress and animals, and later a group of somber men in dark suits, and finally, crowds of tiny people and children climbing up the sides of her wheelchair. These crowded, complex visions rolled before Rosalie’s unseeing eyes like a movie, sometimes amusing, and at other times boring or frightening. Sacks diagnosed Rosalie with a fairly rare condition called Charles Bonnet syndrome, which causes visually impaired people to hallucinate.

In addition to Rosalie, he shares stories about a patient who keeps hearing Bing Crosby’s “White Christmas” play repeatedly, a Parkinson’s patient who watches a group of women trying on fur coats in her doctor’s waiting room, a man who feels peach-like fuzz covering everything he touches and a narcolepsy patient who sees the road rise and hit her in the face as she drives. Hallucinations, we learn, can range from terrifying to inspirational, from annoying to entertaining. One of Sacks’ elderly patients greatly looked forward to her visit each evening from “a gentleman visitor from out of town.”

In these 15 essays, Sacks clearly explains and categorizes an amazing assortment of hallucinations, trying to make sense of phenomena that seem to defy logic. He shares his own tale of a voice he heard when alone on a mountain and suffering from a dislocated knee. Just when he was tempted to lie down and sleep, a voice commanded, “You can’t rest here—you can’t rest anywhere. You’ve got to go on. Find a pace you can keep up and go on steadily.”

No doubt his many avid readers are deeply grateful that the good doctor followed the orders of this life-saving hallucination.

Much like John Updike’s elegant novels, Jonathan Franzen’s fiction paints a rich portrait of middle America as it copes with its failures, its hidden dreams and its ruptures. While Updike’s doughy men and women live their lives locked in a struggle between faith and doubt, Franzen’s characters suffer through boredom and restlessness. And just as Updike’s stylish essays range widely and smartly over a broad range of topics from golf and art to philosophy and religion, Franzen’s graceful essays range widely over topics from ecology and the origins of the novel to theater and ornithology. In Farther Away, his new collection of essays (most of them written over the past five years), Franzen discusses topics as diverse as Defoe’s Robinson Crusoe, Alice Munro’s exceptional fiction (and the reasons it excels in comparison to most literary fiction) and . . . hornets.

The fullest bodied of the essays show Franzen engaging passionately with texts, people and birds. Woven through the essays, and the focus of at least two of them, are Franzen’s attempts to come to terms with the loss of his good friend, David Foster Wallace. Reflecting on Wallace and the late novelist’s engagement with writing and the world, Franzen observes, “At the level of form and intention, however, this very cataloging of despair about his own authentic goodness is received by the reader as a gift of authentic goodness: we feel love in the fact of his art, and we love him for it.” Wallace’s death brings Franzen out of himself, as does his own commitment to environmentalism.

In the past, Franzen’s arrogance has masked his real passion for good writing and has limited his ability to express his deep appreciation for writing that makes a difference, but in these essays he unveils his appreciations. On Randall Jarrell’s introduction to Christina Stead’s The Man Who Loved Women, Franzen reminds us that we “can read Jarrell’s introduction and be reminded of what outstanding literary criticism used to look like: passionate, personal, fair-minded, thorough, and intended for ordinary readers.” With great force and affection he reminds us that James Purdy “continues to be one of the most undervalued and underread writers in America.”

Even though he etches many of them out of pain and loss, the essays in Farther Away offer delightful, poignant, sometimes humorous glimpses of a writer not only struggling to capture a moment in just the right words but also falteringly embracing his humanity.

Like the harrowing tales of swashbuckling pirates and square-jawed detectives in vintage pulp magazines, each beautifully crafted essay in John Jeremiah Sullivan's collection Pulphead is a self-contained world. But where the hodgepodge content of a pulp rag leaps from one escapist fantasy to another, Sullivan's masterful essays invite an honest confrontation with reality, especially when considered in light of one another. By highlighting features of American life as diverse as a Christian rock festival in Pennsylvania, ancient caves and their modern-day explorers in Mississippi, the tragic aftermath of Hurricane Katrina and the King of Pop, Pulphead compels its readers to consider each as an equal sum in the bizarre arithmetic of American identity.

Much of Sullivan’s magazine work for GQ, Harper's and the Paris Review has found its way into this collection, which is fine because the genius of these essays comes from reading them as constituents of Pulphead's patchwork narrative, not in isolation. After skimming the table of contents, you're not quite sure how, or whether, a somber reflection on the state of the Gulf Coast after Katrina will segue successfully into a meditation on the cult of reality television. But it works somehow, and more often than not it works eerily well; that you'll likely find it easy to supply such transitions for yourself, with only a gentle nudge from Sullivan, is a testament to how extraordinarily nimble his writing is.

This sensitivity is most clearly on display in the portraits Sullivan paints of the people who populate his essays. The characters he encounters in his tour of Americana often take on three-dimensional depth with only minimal description. Sullivan can also be devastatingly funny. His account of hauling a 29-foot RV up a steep hill with the help of five West Virginian woodsmen rings with as much absurdity and wit as anything the giants of New Journalism ever put to paper.

It’s hardly a coincidence, then, that Sullivan begins Pulphead by quoting Norman Mailer. In his resignation letter from Esquire magazine in 1960, Mailer writes, “Good-by now, rum friends, and best wishes. You got a good mag (like the pulp-heads say). . . .” Interesting that Sullivan excludes the second half of the quotation, in which Mailer warns Esquire’s editorial board, “you print nice stuff, but you gotta treat the hot writer right or you lose him like you just lost me.”

Omitting Mailer’s punch line is likely Sullivan’s attempt at humility, but make no mistake, he’s as red-hot a writer as they come.

Most journalists strive to write the “definitive piece,” an article so thoroughly researched and reported that it becomes the standard for a particular subject. John McPhee has been writing definitive pieces most of his life, and he offers us a sampling in his new book, Silk Parachute.

After reading an essay by McPhee, you feel you have gained a deep understanding of the topic. Consider “Spin Right and Shoot Left,” an essay about lacrosse, in which McPhee covers not only the history of the game, but all its rules and strategies. When you’ve finished reading, you feel ready to pick up a lacrosse stick and run onto the field. The experience is similar with “Checkpoints,” about fact-checking at The New Yorker. The essay leaves you impressed with the editors’ attention to detail and gives you an insider’s look at magazine publishing.

Many of the essays in Silk Parachute have appeared previously in The New Yorker, where McPhee has been a staff writer since 1965. Over those 45 years, he has written hundreds of essays, many of which have been compiled in one of his 28 books. His body of work includes Annals of the Former World, his authoritative book on geology that won him the Pulitzer Prize in 1999.

Clearly, McPhee is a master of his trade, so it shouldn’t be surprising that he’s accustomed to writing the definitive piece. Yet Silk Parachute also offers a personal side of this accomplished author. In the book’s title essay, McPhee recounts his boyhood memories of his 99-year-old mother, while in “Season on the Chalk,” he relates travels with his family along the English Channel. “Nowheres” is an account of his life in Princeton, New Jersey, where he was born, and where he now resides.

Silk Parachute offers an eclectic sampling from an accomplished author who is as comfortable writing about the intricacies of impersonal topics as he is sharing the intimacies of his personal life.

John T. Slania is a journalism professor at Loyola University in Chicago.

On top of writing acclaimed biographies of Benjamin Franklin and Albert Einstein, former Time managing editor Walter Isaacson has written pieces for seemingly every notable publication in America. This admirable body of work will be elevated even further by Isaacson’s first-rate collection, American Sketches, which offers brief but incisive looks at some of the key figures in recent history.

The book’s beauty is that the entries (ranging from reviews to profiles to eulogies) serve as a kind of late 20th- to early 21st-century history book. Isaacson has shaken hands with history over the last 25 years, whether it was the United States making peace with the Soviet Union, the advances of the digital revolution or the destruction wrought by Hurricane Katrina on his native New Orleans. As a man steeped in American history and the news industry—he was also the CEO of CNN—Isaacson shares his keen observations on the Clintons, Colin Powell and George W. Bush.

With sections devoted to Franklin and Einstein, Isaacson also reveals how the past can inspire the future. He connects Franklin to President Barack Obama by explaining, “I hoped that more politicians would emerge who were sage and sensible, and I came to believe that Obama was the most like Franklin of all our national politicians.” And in his essay “A New Way to View Science,” Isaacson stresses that though Einstein might be associated with hard-to-grasp ideas, people shouldn’t plead ignorance on science.

Ever the biographer, Isaacson delves into icons, discovering what exactly Madeleine Albright did as secretary of state; using a Q&A with Woody Allen to reveal that the famed director eschewed his nerdy onscreen persona when ditching longtime companion Mia Farrow for her adopted daughter; and characterizing George Plimpton as having chosen casualness over literary greatness.

Budding writers should take special note: Isaacson is far from jaded, always curious and open to discovery. It is fitting, then, that while helping out in New Orleans he found his next biography subject: fellow Big Easy native Louis Armstrong. It turns out journalism does have a future, though it might be in unlikely places.

Pete Croatto is a freelance writer based in New Jersey.