Up to now, it has been one of the principal tenets of the critical theory of society (and particularly Marxian theory) to refrain from what might be reasonably called utopian speculation. Social theory is supposed to analyze existing societies in the light of their own functions and capabilities and to identify demonstrable tendencies (if any) which might lead beyond the existing state of affairs. By logical inference from the prevailing conditions and institutions, critical theory may also be able to determine the basic institutional changes which are the prerequisites for the transition to a higher stage of development: "higher" in the sense of a more rational and equitable use of resources, minimization of destructive conflicts, and the enlargement of the realm of freedom. But beyond these limits, critical theory did not venture for fear of losing its scientific character.
I believe that this restrictive conception must be revised, and that the revision is suggested, and even necessitated, by the actual evolution of contemporary societies. The dynamic of their productivity deprives "utopia" of its traditional unreal content: what is denounced as "utopian" is no longer that which has "no place" and cannot have any place in the historical universe, but rather that which is blocked from coming about by the power of the established societies.
An Essay on Liberation