Humans are no longer the exclusive subjects of biography. Other species have biographies now too, and so do mythical figures and diseases. It’s hard to say exactly when this shift occurred. In 1995, Jack Miles called his account of the Hebrew Bible God: A Biography; sounding different depths, Cod: A Biography of the Fish That Changed the World, by Mark Kurlansky, told the history of a centuries-long fishing spree in the Atlantic Ocean. Siddhartha Mukherjee’s recent, Pulitzer Prize–winning The Emperor of All Maladies: A Biography of Cancer is a “life” of the deadly neoplasm. These are excellent books on genuine historical topics, so why the added ballast of the “b-word”? Do publishers fear that in a culture dominated by the personal memoir, people won’t read history unless it’s tricked out as biography?

Bettany Hughes has cleverly navigated the currents of this trend. After reading ancient and medieval history at Oxford, she has spent much of her career making historical documentaries for television. Her first book, Helen of Troy: Goddess, Princess, Whore (2005), was coordinated with a television documentary on the same subject. Most classical scholars would, I think, be bewildered by the idea of writing a “biography” of Helen, who is obviously a mythical character, the object of a religious cult and existing only in the Iliad and the Odyssey and later retellings of her story. Writing the life of Helen is like writing a biography of the Easter Bunny, which somebody may soon undertake. But by turning away from Homer and toward the thin archaeological evidence of the lives of Bronze Age Greek women, which she seemed keen to celebrate in a vaguely feminist manner, Hughes managed to spin a lively bestseller from a nonsubject.

With The Hemlock Cup: Socrates, Athens and the Search for the Good Life (Knopf; $35), Hughes has turned her attention to a figure who certainly did exist, but whose real philosophical beliefs and character are notoriously difficult to disentangle from the literary creations of Aristophanes, Plato and Xenophon that form the main evidence for his life. Hughes opens the book with a good anecdote about discussing her new project with “an award-winning novelist” over a hotel breakfast. “Socrates!” the novelist exclaims. “What a doughnut subject!…Gloriously rich, with a whacking hole in the middle where the central character should be.” It is to Hughes’s credit that she has included this story, because it conveys precisely the strengths and weaknesses of her book. It has a lot of calories—a wealth of information about ancient Athens, though not necessarily presented in the healthiest way. Some readers will lick their lips; others may feel a little sick if they eat the whole thing.

The Hemlock Cup is not a biography of Socrates. Nor is it a book for a specialist, or one that any reader, specialist or not, will want to take slowly. Hughes has nothing to say about Socrates that is not pure cliché: Socrates was “a maverick,” “individual to his core,” “very human,” somebody with a “radical” and “refreshing” “take on the issues of life,” and who “decided to pursue not just the what, but the why.” In general the prose limps along from dangling modifiers to dramatic, verbless sentences to one-sentence paragraphs. Socrates, inspired by his daimonion, was “Rapt. Lost in his own mind.” Vivid. Also annoying. The first sentence of the introduction—“We think the way we do because Socrates thought the way he did”—is, as it stands, clearly false, though you can roughly understand its meaning. There are lots of sentences like that, which one can easily imagine Socrates himself, on a mean day, tearing to shreds.

Readers of Plato may be surprised to learn from Hughes that “Socrates did not believe in or deal with abstracts.” In dialogues such as Laches, Lysis and Euthyphro, Socrates is ostensibly concerned with nothing but the attempt to define the “abstracts” of courage, friendship and holiness. This Socrates may not be a historical character, but Hughes gives no indication of whether, or why or how, she mistrusts Plato as a source. Her use of textual evidence is also sketchy. No sources are given for the injunction “Understand yourself by loving those around you”; one might well doubt that either the historical or the Platonic Socrates held any such belief. Readers may puzzle over what it means to say that “Socrates believed humanity was society”—unless it’s just a rhetorical way of saying that Socrates, like everybody else, knew that people are social. Surely it doesn’t take the wisest man in the world to figure that out.

It’s thanks to her television-presenter’s eye for visual detail that Hughes makes a valuable contribution to the wealth of popular contemporary literature on Socrates. Her descriptions of the physical landscape and material remains of ancient Athens and its environs do not enrich my understanding of Socrates, but they helpfully evoke the world in which he lived. So too do her descriptions of the plague, which made bodies “purple-stained, twisted in the agony of their death throes, their mouths gaping, their dying wish always water, water.” Hughes makes good use of descriptions of artifacts, such as the fifth-century BCE ballot box in the Agora Museum in Athens, used for containing voting discs. Her account of the trial of Socrates is framed by a discussion of the “pissing stream of the water-clock,” the mechanism used in Athenian law-courts to limit a speaker’s time.