Looking at the group of his enormous stone sculptures that recently took up residence at New York's Rockefeller Center, it's hard to believe that the artist is lazy. It gets yet more difficult when considering that the artist recently mounted "pure moonlight," a solo show at Paris gallery Almine Rech (Mar. 9-Apr. 12), "human nature" (through June 7the Rockefeller Center installation) and "primal," a solo show at Berlin gallery Esther Schipper (through May 30). Yet another gallery show, "soul," is now at New York's Barbara Gladstone (through July 3), while "thank you silence," including several series of recent works, opens this summer at the Museum M, in Leuven, Belgium (June 26-Oct. 6). He also has a piece in Expo 1, the multi-exhibition initiative that opened yesterday at MoMA PS1.

Of course, Rondinone didn't mean to characterize himself as lazy, only his work. And what he really means by laziness is stillness. As he explained in an interview with Jarrett Earnest published in this month's The Brooklyn Rail, "What interests me most in art is its inherent slowness. I associate slowness with the possibility of being able to be. When things are going slowly, the scale of measurement and values itself begins to dissolve." The result of such meditative disorientation, Rondinone believes, is profound change. As he told The Brooklyn Rail, "It's a magical transition. It transforms you and nothing is ever like it was before."

Thus the idea of scale, both in physical size and in terms of the passing of time, is crucial for the artist. Rondinone's current show at Schipper, for example, features a herd of 34 tiny sculptures of horses placed directly on the gallery floor, turning viewers into giants. And last year he scattered a similar group of 59 little birds over the two floors and staircase of The Common Guild in Glasgow, Scotland. The small animals seen in both exhibitions were quickly and expressively modeled from clay before being cast in bronze. The artist's fingerprints can still be seen, turning both bodies of work into frozen moments. Critical attention was also paid to every spatial variable in both of these installations, including covering gallery floors with fresh plywood and whitening the windows. Both spaces were suffused with a creamy, timeless light underscored by the presence of stained glass clock faces lacking hands.

Ranging from 16 to 20 feet tall and weighing up to 30,000 pounds, Rondinone's featureless and armless stone figures at Rockefeller Center conversely turn viewers into Lilliputians. Cranes were required for their assembly, but they evoke prehistoric monuments such as Stonehenge and Easter Island. Variations in position and proportion give each its own impish personality, setting up a dialogue of contrasts with the Center's numerous Art Deco sculptures and reliefs of the heroic human form.

A more intimate interaction with Rondinone's stone homunculi is possible at Barbara Gladstone's 21st Street space, where a crowd of 34 related smaller sculptures is present, at sizes ranging from 20 inches to 10 feet high. Some rest on poured concrete pedestals on the gallery's concrete floor, contrasting with the floor's recently liquefied material with the bluestone's ancient hardness. Patches of moss peek out from between some of the joined stones, as if ancient figures had been found in situ and moved in to the gallery.

"I don't have to understand an artwork through linguistic conventions; I have only to feel it," Rondinone also explained in The Brooklyn Rail. His surprisingly emotional rock figures are poignant and alive, whatever their size.

PHOTOS: Top, Ugo Rondinone, The Like, 2013, bluestone, 20 by 5 by 3 inches. Copyright Ugo Rondinone. Courtesy Gladstone Gallery, New York and Brussels. Bottom,installation view of Rondinone's exhibition "soul" (through July 3), at Gladstone Gallery, New York. Photo David Regen. Copyright Ugo Rondinone. Courtesy Gladstone Gallery, New York and Brussels.