 Trying to strike a balance between the insights of Renato Poggioli and the claims of Clement Greenberg, Rosenberg suggested that from the mid-1960s onward progressive culture ceased to fulfill its former adversarial role.Since then it has been flanked by what he called "avant-garde ghosts to the one side, and a changing mass culture on the other", both of which it interacts with to varying degrees.This has seen culture become, in his words, "a profession one of whose aspects is the pretense of overthrowing it."