Living between Paris and New York, Alexander Calder had increasing contact with the major proponents of the European avant-garde of the 1930s. He moved among the various art-world factions without aligning himself and with little concern for their rivalries. Upon seeing Calder's motorized sculptures in fall 1931, Marcel Duchamp dubbed them mobile, as he had his own motorized work decades earlier. Calder embraced the meanings implied by the French term, both referring to a motive and something movable, even quick and unstable, and used it for those works where elements moved by currents of air. When Jean Arp saw Calder's moveable work in 1932, he coined the term stabile to refer to Calder's static constructions.
In the late 1930s, Calder began to favor forms that suggested plants and animals over galactic subjects. Like the Surrealist artists he often exhibited alongside, Calder held an affinity for biomorphic forms and accidental relationships. Calder's mobiles—with individual elements that combine and recombine at random—create a poetry of the unexpected similar to that of Man Ray's “encounter of a sewing machine and an umbrella on a dissecting table” or Arp's chance collages, as well as mimic the unpredictable and passing movements of nature. Calder continued to reference the natural world in his nonfigurative work throughout his life, as in the monumental mobile Red Lily Pads. Its ovoid disks float parallel to the earth in fleeting arrangements, like leaves skimming the surface of water.
Escaping the tensions of World War II, Calder returned to America where in the 1940s and 1950s he remained apart from the abstract artists of the New York School, preferring the company of émigré artists such as André Masson and Yves Tanguy, who like him, made no claims for the underlying meaning or emotional content of abstract expression. Jean-Paul Sartre, brought by Masson to visit Calder's studio in Connecticut in 1946, was attracted to the transitory properties of his mobiles and wrote, “Calder establishes a general destiny of motion for each mobile, then he leaves it on its own. It is the time of day, the sun, the heat, the wind which calls each individual dance . . . . One sees the artist's main theme, but the mobile embroiders it with a thousand variations. It is a little swing tune, as unique and ephemeral as the sky or the morning. If you have missed it, you have missed it forever.”