MOST SOLO EXHIBITIONS require little explanation of why or how they came to be. Their logic inevitably seems to fit some well-established category: There is the midcareer survey or the full-dress retrospective, or the show that concentrates on a single genre or theme. Why, then, does it seem less than easy to slip “Take your time: Olafur Eliasson” into a ready-made slot? There is no question that the show, billed as a survey and initially mounted at the San Francisco Museum of Modern Art by curator Madeleine Grynsztejn, provides the amplest US presentation to date of the work of the forty-one-year-old Berlin-based artist—as was its aim. And with an additional four venues in the offing, it is destined to serve as a milestone, perhaps even a watershed, in what until now has been a mostly European career.

Yet all this notwithstanding, problems emerge. What sort of encounter is this? What does the show offer its viewers? Consider the fact that Eliasson is said to have produced five hundred works in a career whose span is nearly two decades long. The SF MoMA survey included only twenty-two pieces, eight of which were dropped from its next incarnation, the exhibition curated (or re-curated, or even “remagined,” to use an Eliasson term) by Roxana Marcoci and Klaus Biesenbach. Fleshed out by the addition of multiple small-scale models and twenty-four new works (six of which, including the title piece, Take your time, 2008, were newly conceived for the show), the result was mounted in simultaneous presentations at the Museum of Modern Art and P.S. 1 Contemporary Art Center, both in New York.

It is obvious that neither survey could claim to be definitive. Any such purpose would have been doomed from the start. No museum could encompass (indeed, both shows barely referenced) the artist’s great series of urban interventions: Erosion, 1997, for example, which flash flooded the streets of Johannesburg with that all-too-scarce commodity, water, briefly stopping traffic in its tracks; or Green river, begun in 1998, the watery dye job that has brought a brilliantly ironic “greening” to beleaguered rivers from Los Angeles to Stockholm to Tokyo. Works like these are not really site-specific, but they do depend on specific conditions—drought, a river—that museums can neither provide nor evoke. (I say this guardedly, though, given that in The weather project, 2003, Eliasson proved capable of bringing the sun inside the museum—an illusion that, until he managed it, seemed a near-impossible feat.)

In fact, the main issue for Eliasson, under most exhibition circumstances (whether inside or outside), seems to be not so much site as context—context defined, as he explained in a 2003 interview with critic Angela Rosenberg, in terms of a “progression constantly in dialogue with the viewer.” With such progression come ideas of space, duration, viewing, and the necessary destabilization of this triad—a process of unsettling that is made all the more urgent by the museum’s “cultural confinement,” to dust off Robert Smithson’s handy term—a concept acknowledged by Eliasson even as he updates it to speak to the long-established and more or less pervasive institutional insistence on blinding viewers to their own perceptions. After all, museums live to promote (and live by promoting) two linked prerequisites of decontextualized viewing: the masterpiece and middle-class leisure. Whereas for Eliasson, “seeing yourself sensing”—being alert, that is, to your self and surroundings—has long been the goal. That project cannot help but be contextual: It imagines its viewers individually rather than collectively and targets them each as they move through the spaces of the show.

Evaluating these two exhibitions, then, is not a matter of opining on which is the “better” of the pair. Or at least this strategy is off-limits if the aim is to grasp what artist and curators have joined hands to say. Both shows represent major collaborative efforts; both involved the efforts of individuals (Grynsztejn, Marcoci, and Biesenbach) long committed to Eliasson; and both required an enormous outlay of institutional resources—the aforementioned space and time, now measured in curatorial hours, internal deal making, painstaking production, meticulous installation, and the deepish carbon footprint required not only to move thirty-odd assistants from Berlin to Manhattan and San Francisco, but to haul the art as well. Not that the works’ materials are all that onerous. Moss doesn’t weigh much, photons even less; but presumably when the moss travels from an Icelandic farm to a West Coast museum (even if imported as an agricultural product, as was the case here), the tariff adds up.

In “Take your time,” “your” perception is the theme. For Eliasson the topic is not new. Yet it seems to have taken a while for him to realize who exactly this “you” might be, and how they should be disposing of their time. The earliest piece either show offers—Wannabe, 1991, at P.S. 1—makes this clear. Conceived while the artist was still a student, the work consists of a ceiling-mounted spotlight that casts a cone of light on the floor. The small bright pool would be perfect for a nightclub crooner; all it asks is for someone—some would-be performer—to take the one small step needed to enter its glow. “Come, stand here,” it says, not quite sure whether seduction or desperation haunts its words. In this, of course, the piece itself is the wannabe, as much as or more than its viewer. Its shaft of light looks ready and willing but still a bit uncertain what to do. Eliasson’s advice to his spotlight? Just be yourself.

If Wannabe already offers a small allegory of Eliasson’s basic hermeneutics, in Queens its message is given a brilliantly pointed “context,” if we define that term according to the meaning the artist has assigned to the word: The work’s charged implications emerge so clearly at P.S. 1 because it is joined there by Mirror door (observer), 2008. One of a group of four Mirror door pieces—the other three, Mirror door (user), Mirror door (spectator), and Mirror door (visitor), all 2008, are on view at MoMA—this version bounces its spotlight (Wannabe’s heir) off a door-size mirror so that it splits into two half circles, one on the floor of the gallery, the other its reflected twin. One seems “real,” the other “illusion,” but nonetheless they fit together precisely, making a perfect whole. And that unity makes us falter when it comes to finally deciding which half is which—which real, which illusion. In bringing them together, Mirror door (observer) figures—or engineers—the apparent reversal, or annihilation, of a fundamental perceptual dyad. “Never the twain shall meet,” writes Kipling. But in this piece, as so often in Eliasson’s work, complements conjoin. As Wannabe only began to realize, the artist’s more recent practice is at pains to catalyze a consciousness of the active collaboration of all the elements of the basic artistic equation—light, space, duration, the viewer—in short, of context, as their maker defines the term.

At least as powerful as the contexts of Eliasson’s work, however, are its intertexts—the conversation it is actively conducting with art of the recent past. Or perhaps it would be better to say that the artist’s large ambitions mean that intertext and context are one and the same. For although his production is steeped in the science of sight and the physics of light, the artist also clearly understands it as part of a historical lineup—again, a progression of sorts. Take a (slow) stroll through the galleries: The work wears its heart on its sleeve. The 1960s have been the most consistent touchstone—Gordon Matta-Clark, Michael Asher, James Turrell, Robert Irwin, Dan Flavin, and Smithson, of course, all have a place on the list. To enter The natural light setup, 2008, for example, is to be in the presence of the infamous Ganzfeld, stock-in-trade of both military sensory deprivation experiments and the Light and Space artists who made use of them: A computer-driven bank of fluorescent fixtures, cool and warm, has been installed on the ceiling, then hidden behind a taut white scrim. The result is a visual blitz in which most familiar reference points instantly fall away—a simple enough setup (more so than related experiments in color using filters and mixtures) and one that manages to bridge the space between Turrell and Flavin, even while creating a consciousness of the powerful differences within artificially “natural” sources of light.

To be sure, this aspect of Eliasson’s work has been much remarked on, most recently by Pamela M. Lee in a contextualizing essay for the exhibition catalogue. Yet the show itself allows still other affiliations to emerge: Ventilator, 1997, for example—the altered fan that at both MoMA and SF MoMA hung from the heights of a multistoried atrium—cannot help but conjure Hans Haacke’s better-behaved Blue Sail, 1965. Blue Sail uses a fan’s oscillations to keep aloft a tethered square of cobalt chiffon that fills and empties with every variation in the machine’s windy breath. Ventilator, by contrast, buzzes over viewers’ heads like a maddened hornet; yet like the sail’s billowings, its jerks and plunges are the immediate responses of a small open system to ongoing contextual change. And like Haacke himself, Eliasson seems at his best when his work is at its most economical. Which is not to deny their differences: From the elder artist’s Condensation Cube, 1963–65, to the younger man’s Beauty, 1993, much has changed. But the sheer systemic resolution of both pieces—their rightness—means that both deserve the beauty accolade, all irony aside.

One of the great pleasures of both the SF MoMA and MoMA presentations is their inclusion of dozens of the experimental models that, along with computer-generated data, are the Eliasson studio’s main investigative means. Arrayed on white-painted shelves that might have been salvaged from Dr. Caligari’s cabinet, these small and sometimes rickety shapes recapitulate a phylogeny of visionary form. Old friends seem to wave from every corner: Tatlin, Meyerhold, Sant’Elia, Gabo, Brancusi, Escher, Bucky Fuller. Eliasson has put himself on intimate terms with all these innovators, not least by producing variations on their formal themes. On display, to give an incomplete list, are towers, pavilions, lattices, kaleidoscopes, domes, and polyhedrons in wood, plywood, balsa wood, paper, bent and soldered copper, clay, glass, mirrors, magnets, and stainless steel. Some of the frames and lattices have been covered in stretchy panels that seem to be cut from panty hose (black, red, “flesh,”); others in aerial photographs (snow, freeways, parking lots, deserts) or newspaper, including the comics—a “Mickey goes geodesic” moment that reminds us (not that Eliasson’s work conceals it) of the close link between experiment and play.

To present the collection of models is to offer both a vivid guide to the artist’s working method and a revealing index of his fixation on certain basic forms. None is more frequently repeated than the three-dimensional hexagon or “quasi brick” that, for Eliasson, seems to serve as a rejoinder to Minimalism’s preoccupation with the cube: The model room shows versions in paper, glass, clay, and stainless steel. Why this shape? Because, unlike the cube, it is not tautological. On the contrary, it generates complexity; its guiding principles are variation and change. The hexagonal unit is the building block, for example, of the dizzyingly faceted chamber included in both exhibitions under the title Soil quasi bricks, 2003. When employed in an enclosed context and made from this material (pressed and fired earth), the bricks make a cave or lair fit for a spaced-out troll. (Head-on, however, the form has the regular rhythms of a pristine hive.) But MoMA also presents a distinctly different version of the theme, Negative quasi brick wall, 2003. In a glassed-in Taniguchi corridor boarded up for the occasion, a stainless steel honeycomb has been lined with mirrors and stacked from floor to ceiling, forming a structure that nods to the concept Fuller defined as “tensegrity,” the special strength imparted through the balance of tension and compression. This capacity is also among the artist’s fixations, one focus of his collaborations with the architect Einar Thorsteinn. Yet its structure alone is not really what is so “negative” about the piece. The point is the visual effect of the stacked open form: The mirrored quasi brick explodes the wall, that most basic of modules, and fills it with sharp-edged reflections and crystalline light.

And so we arrive at the artist’s engagement with the work of Robert Smithson, which, as the result of quite different endeavors on the part of the two sets of curators, emerges with greater clarity than ever before. Grynsztejn devoted her show’s largest gallery to that topic, placing at the room’s center Multiple grotto, 2004, a stainless steel sculpture that, through her efforts, SF MoMA now owns. I say “sculpture,” but in fact the work does considerable damage to that very idea. Less an object than a walk-in pavilion, it features a bristling surface composed of highly polished and riveted planar funnels—we might even call them flattened cones, if only to point out that like a cone, each shape might once have come to a point, had that point not been snipped off. It is only inside the piece that these peculiar devices reveal their purpose. Each generates its own kaleidoscope, and each set of reflections mimics a crystalline shape—or, more precisely stated, it builds its crystalline vision while mirroring the outside world. To say it again, still more pointedly, the “real” world creates the illusion of multiple crystalline forms. Together, the funneled transformations are intoxicating and exhilarating: They generate a concentration of visual energy that Multiple grotto aims to capture and display. And this is the kind of energy that Smithson adored. In his Vortex pieces, 1965, of which he made both three- and four-sided versions, he favored mirrored shapes (pyramids and tetrahedrons) to produce what he called “solid-state hilarity,” an “ungraspable architecture” (the phrase comes from Borges) that by definition would be a contradictory foundation on which to build anew.

HOW STRIKING, THEN, that at MoMA the Smithson connection plays such a different role. Here it is construed as photographic above all: In devoting two impeccably installed galleries at P.S. 1 to Eliasson’s photographs (works which at SF MoMA merely served as backdrops for Multiple grotto), the exhibition establishes the older artist, to the (appropriate) exclusion of Bernd and Hilla Becher, as the point of departure for the younger man’s work. For each, photography allows typology—the cataloguing of carefully selected landscape features as the means both to record and to dislodge a sense of place. Hence Smithson producing Pine Barrens, 1968, or a year later shooting the before/after series “Overturned Rocks,” 1969: Think rock, plus empty hole. In Eliasson, such impulses surface in his visual catalogues of Iceland’s islands, horizons, rivers, caves, glaciers, and glacier mills. Gathered together in gridded groups of, say, thirty-six, forty, forty-eight, or fifty-six, these series both capture uniqueness and erase it, an effect only redoubled by the remarkable sense of color—or colorlessness—each suite betrays.

To be clear, all these photographs were shot and printed in color, but the landscape itself (at least as seen through the artist’s camera) often pushes color to the brink of visibility and then snuffs it out. The glacier mill series, 2007, registers its subject—the oddly bodily holes or drains in stagnant ice—in black, white, and faint traces of blue in those few places where the ice is still translucent enough for light to plumb its depths. In Jokla series, 2004, which aerially traces the path of a now partly dammed Icelandic river, no color whatsoever enlivens the river’s progress from frame to wintry frame. And perhaps this is right: The landscape seems so wild, so elemental, and so enormous that we expect no signs of life. A shock, then, to discover the traces of mining in the vastness below. Smithson (unlike Eliasson, who has noted the degradation that development is bringing to Iceland’s wilds) would have been delighted to see them, just as he would have reveled in the slow-motion movement of this glacial wasteland: monumental glue pours, the world ending entropically in ice.

In his 2003 interview with Angela Rosenberg, Eliasson offered a theory of how reality and representation intersect. Perhaps it is not surprising, given the artist’s technological and scientific orientations, that this theory is couched in terms of the senses—indeed, Marshall McLuhan’s hot/cool yardstick seems to be lurking close at hand: “I . . . think that there is a somewhat proportional relationship between what you could call ‘the level of representation’ in which you orient yourself and the engagement of your body and senses. The more senses, the less representational.” The key here is this final sentence, as uttered by an artist who puts such a premium on sensory self-awareness. Clearly, to “see yourself sensing” is to take a step, if not away from representation entirely, then at least toward an awareness of the gap between representation and the real. And the greater the exercise of the sensual faculties, the closer one comes to the real.

Which is not to say, of course, that realism is Eliasson’s goal. He may be romantic and utopian—he doesn’t bridle at either label, though he adds “nonnormative” to both—but he is not naive. Yet would he be prepared to address some other implications of his designs for his viewers and their sight? For surely there is a kind of pathos in being put through one’s optical paces, being asked not only to reawaken one’s powers of vision, but also to see one’s self sensing, as if the mechanisms of vision were really what mattered rather than the elaborate allegory that stands behind the art and science of the work. Why this form of therapy, one wants to ask? Why not ask me to sense myself thinking? Wouldn’t that be a better plan at the present time? Or is it that Eliasson believes that thinking and seeing are not so far apart? “My goal,” he declared in an interview with Der Spiegel this past April, “is to sensitize people to highly complex questions.” By his lights, the greatest complexity lies in the confusions aroused by the real.

In the 1960s, it was Robert Morris who was most interested in art’s potential for retooling the human brain (to say nothing of art itself) by visually engaging our deep-seated notions of shape. He chose the simpler polyhedrons as his testing ground—the cube again, of course, or the pyramid, to name but two. What we intuitively grasp about these objects is the sense of the whole—their gestalt—and for a host of reasons, we initially trust that knowledge regardless of what we actually see. But for Morris this alone was not enough. The gestalt became part of a larger strategy of an artistic re-visioning of both perception and context, a strategy summed up with astonishing economy in Morris’s 1966 mantra: “The better new work takes relationships out of the work and makes them a function of space, light, and the viewer’s field of vision. The object is but one of the terms in the newer esthetic.” For many, this is where the politics of Minimalism (and much that follows it) had its start.

There is no question that Eliasson’s art has taken its place among the “better new work” of the present day. This is true not least because of his renewed encounter with phenomenology; as he was for Morris, Merleau-Ponty is a household god. In an Artforum interview in May 2005, Eliasson explained the larger potential of phenomenologically conditioned perception: “It introduces a kind of relativity to our experience. There’s a social aspect to actually allowing you to change your own surroundings by means of your actions. You become essential and central instead of being in the periphery and organizing yourself around a fixed center.”

Confident words, describing a productive anarchy of selves. If only we could be more certain that the lessons imparted in the museums of New York and San Francisco are capable of transplantation to other social soil. Lying under the slowly turning mirror at the center of the P.S. 1 presentation (the moon to The weather project’s sun), it’s easy to feel one’s pleasure as laced with doubt—even when taking one’s time. It is only in retrospect, when weighing that experience as not only visual but also allegorical, that its critical ironies—and political purposes—come into view. The most powerful illusion created by the silvery surface is that the world is revolving around the individuals gathered in a New York institution—and now Eliasson’s central question reemerges with added force: What is illusion, and what is real?

“Take your time: Olafur Eliasson” is on view at the Museum of Modern Art/ P.S. 1 Contemporary Art Center, New York, through June 30. The exhibition travels to the Dallas Museum of Art, Nov. 9, 2008–March 15, 2009; Museum of Contemporary Art, Chicago, summer 2009; and Museum of Contemporary Art, Sydney, winter 2009–2010.

—Anne M. Wagner is a professor of modern and contemporary art at the University of California, Berkeley.