The sort of work Alloway had in mind featured in his celebrated Systemic Painting exhibition which ran at the Guggenheim from September 21 until November 27, 1966. Originally, when he had proposed the exhibition in June 1964, he had intended also to include sculpture, but news that the Jewish Museum was planning Primary Structures for spring in the same year led him to reconsider because it “covered the ground too closely to repeat it.”

Alloway's essay was a good example of what his “short-term” art history which, he argued, “locates an artist in a web of topical information, more extensive than art critics usually collect, but fugitive enough to be lost or misinterpreted if left for future collection.” The historical starting point in his essay was the uncontroversial one that the “Action Painting” core of Abstract Expressionism stressed improvisation, the directness of application of materials, and the recording of the process of making, combining to define the work of art as “a seismic record of the artist's anxiety.” The “Abstract Imagist” core—Newman, Rothko, and Still—avoided the “lore of violence” in favour of quieter, calmer painting. Newman meant more to an emerging generation than Rothko because his aesthetic, less ethereal and romantic, had a greater objectness about it: it was holistic with an “even but not polished, brushed but not ostentatious paint surface.” Furthermore, his narrow canvases of 1951, just a few inches wide, but human height, prefigured the development of the shaped canvas ten years later. Other alternatives were provided by artists such as Alexander Liberman whose “symmetrical and immaculate” paintings of the early 1950s achieved “the random activation of a field without gestural traces” to the extent that they eschewed “touch”; Leon Polk Smith, who “suppressed modeling and textural variation” in his painting in the 1950s; Ad Reinhardt; Frank Stella; Kenneth Noland; and Ellsworth Kelly and Hard Edge painters. A “shift of sensibility had occurred.”

Greenberg re-enters Alloway's argument at this point because of his coining of the term “Post-Painterly Abstraction” as a catch-all for post-expressionist tendencies. Greenberg borrowed from Wölfflin the idea of cyclical development: linear was now superseding painterly.