Dario Gamboni has a keen eye for significant art-historical projects. In his earlier book with Reaktion, The Destruction of Art: Iconoclasm and Vandalism since the French Revolution (1997), he addressed a topical theme—art vandalism—with a high degree of historical nuance and depth. Potential Images shares these qualities. Gamboni examines a phenomenon with which both art historians and more casual viewers of the visual arts are familiar: the intriguing if evanescent tendency to see what we construe as hidden or ambiguous images in works of art and decorative schemes. Citing Marcel Duchamp’s view that “it is the ONLOOKER who makes these pictures” (9), Gamboni parses the varieties of accidental, hidden, and indefinite images from what he argues are the interlocked perspectives of the work’s creator and its receivers. Both poles—the visual trigger and its resolution in the viewer’s perception and imagination—are necessary to the understanding of what Gamboni engagingly calls “potential images.”

It would be easy to dismiss the human profiles we see in Dürer’s View of the Val d’Arco (ca. 1495), for example, as an artist’s whim or joke. Or, taking Leonardo’s famous advice that artists should spark their imaginations by attending to accidental forms in nature—counsel to which Gamboni returns throughout the book—we could again take too lightly such potential images because we see them as accidental and merely subjective. No doubt some viewers have their obsessions with what they think they can see in certain works, but Gamboni’s careful taxonomy of the history and psychology of potential images makes even the most idiosyncratic responses part of an extensive pattern in the history of Western art. It is ironic that Gamboni analyzes such apparently accidental images systematically, that he looks critically at the extensive employment of these clandestine actors on the art-historical stage. Amusing and fleeting as such images may be, he shows that we must take their presence seriously.

The book unfolds chronologically. With passing acknowledgement of other visual traditions, Gamboni elaborates a history of potential images in European art and its theoretical matrices. Many of the examples are familiar—the horseman in the clouds in Mantegna’s St. Sebastian (ca. 1459) and Leonardo’s methods for “stimulating the mind to various discoveries” (29). But finding new potential images is not Gamboni’s point (though he does indulge in the odd potential discovery). Gamboni instead underlines that the deployment of potential images suggests the increasing importance through the Italian and Northern Renaissance of both artists’ and viewers’ active visual imagination. This priority is consolidated in the eighteenth century, most famously with Alexander Cozens’s “blot” technique, the practice of the accidental that he proclaimed in A New Method of Assisting the Invention in Drawing Original Compositions of Landscape (1785). The significant population of potential images that Gamboni examines may be various, but they are precisely not random. In the use of potential images, Gamboni finds a pattern of liberation in Western art that affects us still. “The shift in aesthetic communication . . . taking place between the 1880s and the First World War,” he writes, “subsequently had an effect on all artistic production that claimed to belong to Western modernity and also on its reception” (201). Citing Christophe Bode’s study of visual ambiguity and, before him, Umberto Eco’s commentary on “the poetics of the open work” (9), Gamboni claims that the uncertainty of potential images is constitutive of modern visuality.

Gamboni’s account is not teleological. The center of his enquiry is a span of forty years from ca. 1880 to 1920, a time “during which the notion of representation and the various forms it takes are questioned and challenged” (9) with what I—if not Gamboni—would claim is unprecedented vigor. This time witnesses the high point of the potential image in terms of its frequency of appearance, its experimental manifestations in photography, film, and the more traditional visual arts, its crucial imbrication with experimental psychology, and its encouragement by discoveries about the atom and fourth dimension. The heroes of Gamboni’s book—Redon and Duchamp—exercise great influence at this time. While Gamboni’s research is the most detailed in these central chapters, it is to his credit that the framing work on earlier and later developments around the potential image does not seem merely to lead up to or trace a decline from the advent of Symbolism, Cubism, early abstraction, and the beginnings of Surrealism.

Gamboni’s study is ambitious and thorough. He provides the opportunity to think about a considerable sweep of European art from an oblique perspective, one that he makes visible in a number of productive ways. His is an art history with the names and “isms” very much included. If you think of an artist who trades on potential images for the effect of his paintings—Turner in Venice, for example—that work will be discussed. If you think of a movement for which ambiguity and the suggestibility of the image is crucial to its artists and viewers alike—Surrealism in the hands of Ernst, for example—that movement will be discussed. The drawback of this comprehensive approach, of course, is that Gamboni must move quickly through many of his analyses. The book is heavy with helpful bibliographical references, but specialists in a given area will often find that Gamboni’s sources are not the most recent. Even in what he calls the “heart” of the book, the sections covering the 1880s to 1920s, specialists in this material (of which Gamboni is one) might wonder why his sources on the beginnings of abstraction, for example, include only the abidingly significant but nonetheless often superseded work of Sixten Ringbom and others from the 1985 Los Angeles County Museum of Art catalogue The Spiritual in Art: Abstract Painting, 1890–1985 and accompanying scholarship from this and earlier decades.

Early abstraction is the best and the worst example of the use of potential images. Certainly, as Gamboni rehearses, abstract paintings from the early twentieth century seemed ambiguous at best to most viewers. Given that audiences were habituated to representational art, naturally they would look for the sort of hidden imagery that Kandinsky especially built into his work as a stepping stone to the transcendent. While Gamboni is also right to insist, citing Picasso, that the line between abstraction and representation is in many ways a false one, that does not mean—as Gamboni also claims—that representation was not at times rejected in the work of the pioneering abstractionists. In what way, for example, were Malevich’s monochromes representational? Of “nothing” or what he called “zaum” space? The same question arises with Yves Klein and with Lucio Fontana, two other artists not mentioned here. Gamboni does briefly discuss the recent abstraction of Gerhard Richter and again validly insists on its ambiguous relationship to identifiable imagery. But his overall reading of abstraction in the twentieth century is shaky. If indeed abstraction is at times fully non-representational, how could it imply or trigger potential images in anything but the most trivial sense?

Gamboni’s laudable desire to complete his survey also leads to dubious interpretations in the case of Robert Smithson. As Gamboni claims, Smithson’s earth art is a bridge between Minimalism and a large-scale image-making practice most dramatically rendered in Spiral Jetty (1970). The spiral is for Smithson an important “vision or . . . eidetic image” (226), certainly. Quoting Smithson’s poetic and highly metaphorical descriptions of this “dormant earthquake” on the shores of the Great Salt Lake (226), however, Gamboni delimits as an image what is often an even more widely allusive—I would say entropic—process of analogizing in Smithson’s writing and material production. Smithson worked like nature, a common trope in the history recounted by Gamboni. But in company with some current environmental artists, he took this attention to natural processes well beyond the scope of an image. Yes, viewers must “complete” work by Smithson or an even more overtly interaction-oriented environmentalist such as Olafur Eliasson. But we do not do so only through images, potential or otherwise. The experience is more holistic. Its radicality, in Gamboni’s terms, lies in breaking the conventions of the (potential) pictorial image on which his history depends.

Gamboni writes that “a fundamental characteristic of modern and (for some) post-modern art . . . is the establishment of an open relationship in which the viewer is called upon to collaborate in the development of a work in progress” (241). He shows that this modern trait had its inception in the deployment of potential images in pre-modern eras. Gamboni is a subtle writer. He is well aware of the ironies of systematizing a history of the hidden and of making permanently visible what is really a shared, ongoing process of aesthetic completion. Donald Preziosi has claimed that “the principal aim of all art historical study has been to make artworks more fully legible in and to the present” (“Art History: Making the Visible Legible,” in Donald Preziosi, ed., The Art of Art History, Oxford: Oxford University Press, 1998, 14 [emphasis in original]). Gamboni’s admirable study does just this: where the appearance of potential images may have seemed incidental, we can now see a thoroughly modern strategy on the part of artists and a concomitant assumption on the part of viewers. The challenge for Gamboni and the future of potential images is to keep the story going, to maintain the openness of creation and reception rather than to conclude art history by giving such images a final address, by flipping the potential image into something actual.