The author launches his critical archaeology of postwar avant-garde ideology by making an initial incision at the site of sculptor Richard Serra’s “extension” of a nineteenth-century Swiss viaduct modified by engineer Robert Maillart in the 1920s. Contra the prevailing orthodoxy which reads Serra’s sculptures “phenomenologically,” as radically abstract interventions into the embodied viewer’s perceptual space, Maillart Extended is interpreted here as an “allegorical” work—or as a dialectical image which embodies the radical incommensurability of two opposed ideological, aesthetic, and material paradigms.