Is this the age of the short biography series? It began with Penguin Lives, which was, in part, a reaction to the brawny biographies reviewers have been complaining about for a generation or more. The Penguin authors were not just professional biographers and scholars. Novelists like Louis Auchincloss and Mary Gordon essayed accounts of Woodrow Wilson and Joan of Arc, respectively. These writers were inspired choices: Mr. Auchincloss was steeped in the period of Henry James and Edith Wharton, out of which Wilson emerged, and, of course, one had to find out what Ms. Gordon’s Catholic sensibility made of a martyr.

Henry Holt’s “American Presidents” series, edited by Arthur M. Schlesinger Jr., takes a similar tack. Whereas historian H.W. Brands assesses Wilson, E.L. Doctorow (a novelist in the Dos Passos tradition) limns Lincoln, and the indefatigable Louis Auchincloss appraises Wilson’s nemesis, Theodore Roosevelt. As with the Penguins, this series puts a premium on fluent prose. The successful short biography is a portrait and a lively appraisal; it cannot do the work of full-scale biography. But often compression expresses more than expansiveness.

Now W.W. Norton has a fine series called “Great Discoveries,” and again it is peopled not merely with experts, but also with literary types like William T. Vollman, who will confront Copernicus in a forthcoming biography. Barbara Goldsmith has already published “Obsessive Genius,” a superb brief life of Marie Curie, in this series. “Great Discoveries” is the brainchild of the same man, James Atlas, who founded Penguin lives. Mr. Atlas has also, in the past year, helped launch another series of short biographies (on business people) for Norton, called “Enterprise,” as well as the “Eminent Lives” series for HarperCollins. It really is not possible to review all the short biographies produced by Atlas Books, let alone all of the other imprints.

Yet the willingness of scholars to write short biographies for a general audience is one of the most encouraging developments of recent years. It used to be that most introductions to writers consisted of a short biographical chapter followed by chapters on the subject’s work. Literature professors might like this approach, but to the biographer this kind of carving up of writers’ careers destroys the flow and rhythm of life, especially when the writer has published in many different genres. In such academic studies, the continuum of a life’s work is destroyed.

This is made quite clear now that university presses have begun to get into the short-biographies game. The University of Chicago Press and Oxford University Press have come out with a short biography series called, respectively, “Critical Lives” and “Lives and Legacies.” On the evidence of their first fruits, Oxford’s series will be by far the more interesting and lively of the two.

The first two entries in the “Critical Lives” series, published in England by Reaktion Books and distributed in the United States by Chicago, are quite different from one another and seem to forecast an uneven focus and level of achievement. Chicago touts these biographies as illuminating the “life, work, and transformative ideas of major figures, all in language accessible to a general reader.” In “Jean Genet” (146 pages, $16.95), however, Stephen Barber writes with the academic’s fondness for strange words such as “insurge” and “identicality.”

When he focuses on biography, he provides a powerful backdrop for understanding Genet’s hatred of French society. Genet’s own orphanhood and sense of abandonment, the anomie he experienced in state institutions, help to explain why he considered the family the “first criminal cell in life; a crime that was exacted against the child.” Genet’s novels, personal life, and political activities are explored with admirable succinctness. Even if his novels put off readers because of the writer’s perversity (how much does the general reader really want to hear about the power of the penis?), Mr. Barber’s command of Genet’s literature and his life make his book a good starting point for understanding a sensibility that might other wise be dismissed as simply vicious.

David Macey’s “Michel Foucault” (Gallimard, 160 pages, $16.95), by contrast, is very heavy going. Here is why:

Psychiatry, for example, is a discursive formation born of the intersection of medical, legal and criminological discourses that produces the objects it claims to be treating as it interacts with non-discursive formations such as institutions and power structures.

What? Is Foucault the problem or Mr. Macey? Not being a Foucault adept, I cannot say. But as a general reader, I certainly expect the biographer to do better than this.

Mr. Macey fails nearly completely in relating the life to the work. I simply cannot keep straight in “Michel Foucault” how the philosopher’s books relate to one another or to his life.

I did find Mr. Macey’s account of Foucault’s political evolution compelling, especially Foucault’s realization that Maoism was a disaster for the French left. And occasionally Mr. Macey throws out tidbits of the kind we relish in biographies. It is good to know that Foucault specialized in pasta dishes. Why? Because as Samuel Johnson pointed out ages ago, we want to know precisely those kinds of details that make subjects human.

I also liked reading about Foucault’s devastating dismissal of Jacques Derrida (surely a fraudulent figure). Foucault termed Derrida’s deconstruction a “well-determined little pedagogy.” Mr. Macey follows with: “Derrida’s notorious insistence that ‘there is nothing outside the text’ gave, he [Foucault] pointed out, ‘limitless sovereignty’ to the ‘voice of the master.'” Precisely right: Derrida was another one of those academic empire builders.

The biographer is rather guarded about Foucault’s life as a gay man, but then he has to be, since Foucault himself was rather secretive. The biography contains some speculation, but it is based on Mr. Macey’s profound immersion in his subject’s life. He is the author of the full-length “The Lives of Michel Foucault” (1993). But if Mr. Macey has his moments, I would have to say that the short form is not his forte.

Not so David Reynolds, author of “Walt Whitman’s America: A Cultural Biography,” which won the Bancroft Prize. His shorter Oxford volume, “Walt Whitman” (160 pages, $17.95) is a nice warm-up for the general reader, who is advised to advance to the larger work. The effect of opera, the visual arts, American oratory and the lecture circuit, the stage – all this and more – are canvassed in a compelling portrait of a great American poet.

Mr. Reynolds rightly fastens on the poet as performer. The “real” Walt Whitman is to be found, the biographer suggests, in his role as actor:

Nowhere did he act so much as in his poetry. The “I” of Leaves of Grass has proved puzzling to critics. Some have seen it as a sublimation of private anxieties and desires. Others see it as a complete fiction, with little reference to the real Whitman, as indicated by the many differences between the poetic persona and the man. Such confusions can be partly resolved by recognizing that the “real” Whitman, as part of a participatory culture, was to a large degree an actor, and that his poetry was his grandest stage, the locus of his most creative performances. When developing his poetic persona in his notebooks, he compared himself to an actor on stage, with “all things and all other beings as an audience at a play-house, perpetually and perpetually calling me out from behind the curtain.” In the poem “Out from Behind this Mask” he calls life “this drama of the whole” and extends the stage metaphor by describing “This common curtain of the face contain’d I me for me, in you for you” and “The passionate teeming plays this curtain hid!”

Such passages convey Mr. Reynolds’s capacious grasp of the literature about Whitman, his reading of the primary sources, and his own well-considered view of the man and poet. It is a striking characteristic of short biographies that they are often historiographies – that is, the short biography becomes an enactment and distillation of a biographical tradition that issues forth with a concision as satisfying to the scholar as it is to the general reader.

After Mr. Reynolds, what more could one ask for? And yet Larzer Ziff’s “Mark Twain” (Oxford, 126 pages, $17.95) is just as powerful. One way to speak volumes in a short biography is by way of the epigram. Here, for example, is Mr. Ziff making a fairly conventional distinction between two of Twain’s greatest novels, which he ends with a sentence that could not be more snugly put:

“Tom Sawyer,” told by a third-person narrator, is a loving recall of the joys and anxieties of boyhood, rightfully uncomplicated by adult concerns, whereas “Huckleberry Finn,” told by a boy, is a many-sided critical portrait of an entire civilization. Although both are set in the time of Twain’s boyhood in Hannibal, the profounder implications of “Huckleberry Finn” derive from the adult’s return to his past, chronicled in “Life on the Mississippi.” “Tom Sawyer” is a memory; “Huckleberry Finn” a recognition.

Like Mr. Reynolds, Mr. Ziff is adept at explaining his subject in terms of his cultural background. I especially enjoyed his account of Mark Twain in the marketplace. I had never quite taken in the fact that for most of his career Twain’s books were sold by subscriptions dependent on the door-to-door peregrinations of salesmen. Twain was not available in bookstores; you might call him our first direct-mail novelist. Although Twain would get his share of honors late in life – including an honorary degree from Oxford – he was the man the literati looked down upon. Matthew Arnold, after meeting Twain, inquired whether the man was ever serious. Twain had his admirers in England and indeed around the English speaking world, which he toured as a way of getting out of debt incurred in bad business investments, but his closeness to the ground, so to speak, is what made him great. Or as Mr. Ziff puts it, Twain uncovered the “poetic infrastructure of the American vernacular.”

“Brief, erudite, and inviting” – it seems too much to ask – and yet this is what the Oxford series aims to be. The words could be taken as shorthand for what every short biography series ought to achieve.