The artist Martin Creed once wrote about visiting the Capuchin catacombs in Palermo with some friends. They had arrived minutes before closing time, and Creed remembered “running at top speed…looking desperately left and right at all of the dead people hanging on the walls in their best clothes, trying our best to see it all.” The catacombs are not exactly a museum of art, but they might remind us of one. Sometimes those fine old paintings in their gilt frames do look like luxuriously dressed corpses, after all, and even when we museumgoers are not rushed—when we’re taking our time, looking carefully, standing still—we pass through those great whispering galleries a lot faster than the works of art do. They’re there for the duration.

Before long, Creed took the opportunity to put the art lovers in the position of being raced past. In 2008, at Tate Britain in London, he exhibited Work No. 850—a sequence of runners sprinting at set intervals through the museum’s Duveen Galleries, the building’s long, neo-Classical grand central hall. The work was extraordinary: a new way to express not only the simple idea of an intensely rendered line but also the idea, I couldn’t help but feel, of the extraneousness of the viewer. The runners passed by almost before you could see them; you felt like an afterthought, something left in their wake. “I think it’s good to see museums at high speed,” Creed reflected after his visit to Palermo. “It leaves time for other things.” Because art is longer than life, time is what we need more of.

The temptation is maybe not to run but to glide past the works Creed is now showing at Hauser & Wirth London, Savile Row (through March 5), or the ones Gabriel Orozco is exhibiting in his midcareer retrospective at London’s Tate Modern (through April 25), where it concludes a long tour that began at the Museum of Modern Art in New York in December 2009. Both artists, neo-Conceptualists in their 40s, make a point of reducing the artistic gesture to the smallest effective intervention into reality; even when the resulting objects are huge, they embody a simple perception, an almost nugatory transformation. Creed and Orozco are widely admired for their subtlety and lightness of touch. Isn’t viewing their work a matter of quickly registering an implicit idea, like a seed that can grow in one’s mind in retrospect, rather than of the deep looking and extended contemplation one might accord great works of traditional painting and sculpture? To a large extent, yes, but be careful: you might be skating past the point of the work.

It would be impossible to walk by Orozco’s La DS (1993), without at least stopping for a double take: the sculpture is an automobile, a Citroën DS, that has been sliced from bumper to bumper into thirds, with the middle slab removed and the remaining two pressed together. It’s a bit like the mutant car images Peter Cain was painting around the same time, but right there in the flesh. However big and imposing Orozco’s sculpture may be, once you start looking at it, its presence recedes. La DS is an object that seems to be trying to turn into an image. It’s as if the act of looking at it, whereby you intellectually understand what it is that you’re looking at and why it looks that way, can do nothing to convince some other, less conscious part of the brain that it’s seeing what it’s seeing. It’s hard to stop looking, and the car becomes what Roland Barthes in Mythologies said a new Citroën was meant to be, “a purely magical object.”

Something similar might be said of another of Orozco’s best works, Black Kites (1997)—a human skull on which the artist has drawn a checkerboard grid in graphite. Of course, to draw a grid on a complex, irregular surface like that of a skull is strictly speaking impossible, so the squares that make up the grid get distorted into all sorts of stretched-out shapes, mostly but not always four-sided—kites, as the title has it. Again, a double perspective is forced on the viewer: any given shape has to be seen both as a shape in its own right and as a distorted square, a square in anamorphic perspective. Black Kites is also a brilliant twist on art history. In his 1533 painting The Ambassadors, Hans Holbein famously used anamorphic perspective to insert the image of a skull into a symbolic double portrait; Orozco uses the skull as a device to disfigure the supposedly rational structure of the grid.

Reflections on the possible significance of such an object only follow from its innate fascination, which derives in turn from the perceptual ambiguities it generates. La DS and Black Kites are not the only double perspectives Orozco has devised, but a stroll through the retrospective suggests that they are too few, and perhaps getting rarer with time. More typical perhaps is Elevator (1994). The process of its making recalls that of La DS. An elevator was salvaged from a building set to be demolished; it was then cut into three horizontal slices and the middle removed. According to Tate curator of contemporary art Jessica Morgan, who has written a new book on Orozco’s work (Tate Publishing; $27.50), the resulting reduction in height evokes “the memory of the movement of the lift and the sensation of rising in space to meet the top of the lift cabin.” This is wishful thinking. It might be different if you were allowed to step inside and feel how close your head is to the elevator’s ceiling, but because few people have any sense of what the exterior of an elevator looks like, or its scale, seeing it provokes no visceral sense of the unfitness of the object’s size. You simply observe it flatly, and walk on by.

Until You Find Another Yellow Schwalbe (1995) is a suite of forty color photographs, all showing pairs of yellow motorbikes parked on the streets of Berlin. The backstory is that Orozco, living there at the time, kept an eye out for motorbikes like the one he was using; when he saw one parked, he would park his own next to it and snap a picture. “It was my excuse to go out solitarily and treat the city like a game board,” he says. “The grid of the city is the grid of the board.” What comes across in the work is none of this, but rather a great self-absorption. There may have been a real playfulness for Orozco in the creation of the piece in 1995, but here and now it is a dull, didactic discourse on playfulness.

It could be that I am coming to this art with the wrong expectations. “I want to disappoint the expectations of the one who waits to be amazed,” Orozco has said. He succeeds in this all too often. The disappointment he intends is a sort of amazement in reverse. It plays to the audience by forcing it to forgo an assumed pre-existing expectation in order to notice something else. But the game Orozco plays has diminishing returns, because it doesn’t take long for the audience to learn to like his artistically confected disappointment—and then Orozco is just fulfilling their expectations again. Of course, what any artist does is always, in part, to nudge or cajole us to notice things we don’t think are amazing. We should welcome the nudges. But the artist’s demand that we pay more attention to the world is an identical twin to the child’s demand, “Pay attention to me, whatever I do!” It’s understandable, but Orozco too often mistakes the one demand for the other.

* * *

Paradoxically, what makes Creed’s work as a whole more engaging than Orozco’s is that Creed doesn’t much care if anyone pays attention. While there’s probably a backstory to any of the works on view at Hauser & Wirth—mostly small paintings, but also photographs, wall paintings, a black-and-white film and a large sculpture—a little time spent with them takes the edge off the desire to know whatever their anecdotal background might be. The works don’t open up until you’re willing to accept that what you see is all there is to them. Three large photographs (Work No. 1094, Work No. 1095 and Work No. 1096, all from 2011) show a comically mismatched pair of dogs, one tiny and one huge, a Chihuahua and an Irish wolfhound, romping in a completely white studio. They’re charming to look at, but so what? Well, that “So what?” is the crucial point in any work of Creed’s, the point where you can either shrug your shoulders and walk on or entertain the thought that the insignificant phenomenon before you is worth mulling over—in which case the comical equivalence the photographs propose between the large and small might be all to the point. “His small is enormous,” as one contributor, John O’Reilly, writes in the massive, recently published compendium Martin Creed: Works (Thames & Hudson; $65); in Creed’s Work No. 567 (2006), the phrase small things was lit up in ten-foot-tall neon letters. Paging through the more than 700 works illustrated in the book, dating from 1986 through 2009, one becomes aware that Creed’s numbering system is a way of asserting the equivalence of seemingly unrelated and differently valued kinds of things: a ballpoint pen scribble, some written words, a torn-up or crumpled sheet of paper—the Chihuahuas of art—are simply Works, no more and no less than a theatrical performance or a room-filling installation of balloons—the Irish wolfhounds.

Somewhere in between—basset hounds, maybe—are the paintings that seem to be occupying Creed more and more these days; they evoke a historically prestigious tradition but with simplicity and mostly on a modest scale. There are more than forty canvases at Hauser & Wirth, along with a few wall paintings. Like Creed’s other works, and in apparent contradiction to the title they all share, they don’t really look like they involved much work, and indeed they couldn’t have if the dates they’ve been given are accurate: all but one are dated 2011, which means Creed would have made several every day between New Year’s and the exhibition’s opening three weeks later. Each canvas represents a slightly different, always rather straightforward way of geometrically working through the structure of a rectangle: layers of horizontal lines, ziggurat-like configurations of smaller rectangles within the overall one, sequences of X-shapes and so on; most are symmetrical, either with just two or three colors or many shades of a single color. All are very direct, immediate and concrete; there is always a clear additive structure but also (and their small size helps here) a sense of the singularity of the whole. The paintings, and also the bits of color that make them up, hold their own in space, neither imposing themselves nor receding. They’re good paintings, and all the better in comparison with those that Orozco, too, has lately been producing, in a style best called geometrical baroque. For all their intricacy Orozco’s paintings amount to banal decorations; their gold leaf is not that of icons but of nouveau riche bling.

Whether Creed can continue collapsing the distinction between small and enormous is an open question. His Work No. 1092 (2011) consists of mothers spelled out in giant neon letters atop a steel beam that rotates at varying speeds 6 feet 8 inches above the ground. It looks like it could kill you even though you know that Michael Jordan could stroll under it without getting scalped. It’s a sort of scary joke on the idea of being dominated by mom, or maybe not by mom herself, because the “mothers” are plural, but by some primeval powers “enthroned in solitude sublime,” as Goethe said—and very effective. It’s a bigger idea than Creed usually works with, yet for once he makes you wonder whether the piece hasn’t outgrown its idea. Still, I can’t deny that it held me there, observing it warily, a good long while. I didn’t race past.