Michael Fried at nonsite:
What all this comes down to, then, is that Berger accepts a priori a militant and often staggeringly vulgarized brand of Marxism from which all his judgments about art derive, in language anyway. (Since we are never allowed to view the actual procedure by which Berger judges that one painting is “subjective” or “decadent” and another not—this would involve defining Marxist terminology in visual terms—we can say no more than this.) Furthermore, when Berger finds himself in a position that, even to the layman, is pretty obviously untenable, he is prepared to deny its apparent meaning and then reintroduce the untenable notion through the loaded use of supposedly neutral or descriptive words—such as “improvement” in the above example. My fundamental objection is not that Berger begins from a position of accepting Marxist theory. In the world we live in more and more critics of art may be expected to start from similar political premises. But what is imperative is that the critic define his terms; that he show with sensitivity and logical rigor the usefulness and, if possible, the necessity of employing Marxist concepts and terminology. Unless he can do this his judgments will reveal nothing more than the strength of his bias and the slovenliness of his mind: they can say nothing about the works of art in question.
more here.