This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Constructivism is unusual among modern art movements in that its defining boundary was set not by a founding manifesto but by an internal argument. By 1920, the circle of Moscow artists working in Tatlin's wake, including Alexander Rodchenko, Naum Gabo and Antoine Pevsner, had grown large enough that real disagreements over purpose surfaced. That year, Gabo and Pevsner issued their Realistic Manifesto, arguing that abstract construction, built from space, volume, line and kinetic rhythm, had value as art in itself and did not need to justify itself through direct social utility. Tatlin, Rodchenko and the designer Varvara Stepanova answered with their own Programme of the Productivist Group, insisting instead that the artist's proper role in a Communist society was to become an engineer, designing textiles, furniture, propaganda and architecture rather than making autonomous art objects. A 1923 Constructivist manifesto stated the Productivist position bluntly: the material formation of the object is to be substituted for aesthetic combination, describing the artist's work as a purely technical mastery and organisation of materials. The disagreement was not resolved by debate but by geography. In 1922, Gabo and Pevsner emigrated from Soviet Russia, eventually carrying their spatial, kinetic version of construction to Germany, France, Britain and the United States, where it influenced sculptors for decades. Inside Russia, the Productivist line under Tatlin, Rodchenko and Stepanova became dominant, feeding directly into Constructivist textile and graphic design and into architectural groups such as OSA, before the entire movement was suppressed as Joseph Stalin's government imposed Socialist Realism as the only acceptable Soviet artistic style. Because the movement fractured this way, historians still disagree about which half deserves the name Constructivism: the utilitarian, state-serving Productivism that stayed in Russia, or the more purely formal, internationally influential sculpture that Gabo and Pevsner carried abroad.