"La Folie Baudelaire," by Roberto Calasso Roberto Calasso is noted for being an intellectually challenging writer. He is supremely learned, wearing his gigantic erudition ostentatiously on both sleeves. He can prestidigitate with prestigious quotations from, and references to, everything from the Vedas to Hollywood. His new book to us (in ­Italy it is already penultimate) is "La Folie Baudelaire," with the folly perhaps as much Calasso's as Charles Baudelaire's, equaled only by that of the unsuspecting reader embarking on a hoped-for smooth sail. As Calasso himself might put it, "Caveat lector!" Already in his title, Calasso is eruditely punning, or as he would probably say, paronomastic. For a folly is not only a common human flaw; it is also, as an 18th-­century term has it, a garden pavilion propitious for daydreams. Calasso, however, is more likely to have used any gazebo for omnivorous reading, as he is the consummate polyhistor. He has published books on such diverse subjects as Greek and Hindu mythology, Talleyrand and his age and Tiepolo and his use of pink (inspired by a comment of Proust's), Kafka and now this, about artist-innovators of the later 19th century (or ottocento): poets, painters and prose writers, with Baudelaire as the central, in some ways seminal, figure. One would assume that there is also a central theme, and there sort of is: Baudelaire and Paris as the cradle of modernity. But it is all a trifle arbitrary. Ingres and Delacroix are here at some length, both topics of Baudelaire. But also a fairly obscure favorite of his, Constantin Guys, whom he elevated to "the painter of modern life." So too are Manet and Degas, but only passing references to van Gogh and Cézanne, Baudelaire not having advocated them. There is a brief chapter on the adolescent Rimbaud, and a fair amount about the critic Sainte-Beuve, but again only incidental attention to Mallarmé and Valéry. Balzac and Stendhal get intermittent notice, as do Chateaubriand and Flaubert, but no chapters. Laforgue earns a number of paragraphs, but Lautréamont very few, and Corbière none at all. On the other hand, Berthe Morisot, a worthy but minor painter, figures rather prominently, both as painters" model (as shown in several of the book's illustrations) and as Manet's lover and subsequent sister-in-law. The book fluctuates between criticism and biography, which is fine; what is lacking, however, is a clearly conveyed thread that unites all this material - the sort of thing we get from another modern Italian scholar-critic, Mario Praz, in "The Romantic Agony" (not the Italian title) and "The Hero in Eclipse in Victorian Fiction." Calasso's "folly" cannot escape his playing favorites, perhaps the willfulness of the privileged child of a highly cultured and prominent family, as well as the literary freedom available for lifelong work at a distinguished publishing house, whose chairman Calasso became in 1999. A case of publish or not, but never perish. Yet to stress again, "La Folie Baudelaire" is no easy reading: sometimes the sentences are too complex, sometimes the references too abstruse. Already in the second paragraph we are treated to E. M. Cioran, Gide, Walter Benjamin, Nietzsche, Maurice Barrès, Jacques Rivière and Proust, and some such literary hopscotch continues pretty much throughout. Mannered utterance often turns impenetrable. If you are given to labeling forbiddingly opaque statements with question marks, your margins will easily inherit 70 or more - many more if you are less forgiving. But first, let us give praise where praise is due. At his best, Calasso can be quite impressive, as in the following: Modernity: a word that emerges and rebounds between Gautier and Baudelaire in the space of a little more than 10 years . . . between 1852 and 1863. And this was always done with caution, with the awareness of introducing an alien notion into the language. Gautier, 1855: "Modernity. Does this noun exist? The sentiment it expresses is so recent that the word may very well not be in the dictionaries. Baudelaire, 1863: "He is looking for that something we shall be allowed to call modernity; since there isn't a better word to express the idea in question." But what was this idea . . . so recent and feeble . . . made of? The malicious Jean Rousseau immediately declared it was made up of bibelots and female bodies. Arthur Stevens responded to him in defense of Baudelaire, defined on the occasion for the first time as "he who is the inventor, I believe, of this word modernity." Through painting and frivolity, modernity burst into the dictionary. But it was destined to remain and spread, following progressive campaigns of conquest, accompanied by devastation. Soon no one would remember these frivolous and modest beginnings. In Baudelaire, however, the word remained enfolded as in a mist of perfume and face powder. Even this, though, is unclear about that "devastation," and although "mist of perfume and face powder" is fetching, it may be more suited to verse than to prose. John Simon, a longtime critic of the arts, is the theater critic for The Westchester Guardian and The Yonkers Tribune.