In case it helps, this is literary theory (aka "theory"), not philosophy. Although there is definitely communication between the two fields, they have their ow

In case it helps, this is literary theory (aka "theory"), not philosophy. Although there is definitely communication between the two fields, they have their own traditions and their own vocabularies. One of the more obvious differences (and here I am comparing with analytic philosophy specifically) is that literary theory is often quite allusive where an otherwise equivalent philosophical argument would be explicit. I think the reason for the difference here is that in philosophy, the goal is clarification of the argument itself, while in literary theory (from my outside perspective I believe) the goal is a sustained state of aporia. Note: I am by no means an expert in literary theory, but I thought I would give my reading of the sentence you quote. Jameson is summarizing the previous few paragraphs of the review, where he describes the "generic problems of political, indeed utopian thought". The basic problem is this: how do you talk about major changes to the way society works? At the time period discussed, just as at any other, there were a lot of big ideas about how society ought to be organized, but they did not come with instructions for implementation. Wittenberg (according to Jameson) says that what Wells brought to the table was a literary device to allow an examination of the alternative organization of society without the need to focus on the transition between the current society and the imagined one, in a way dissolving the problem. "Differentiation" refers to the notion that a society can be viewed in some ways as an organism which attempts to restructure itself to represent and respond to its surroundings. So Jameson is just using a fancy but allusive way of restating and generalizing the claim that Wells was introducing a new way for society to talk about changes to itself. I'm not saying I agree or disagree with this, and I definitely can't comment on whether Jameson is characterizing Wittenberg's book correctly, but I think that's what is being said.