Georg Simmel's writing is full of ideas; and while it seems like you should be able to say this of any philosopher or theorist of note, I think GS gives an unusually strong feeling of an active mind deluged with possibilities, searching for at least a temporary way of disgorging them in a useful and convincing manner. His training was in Neo-Kantian philosophy, and he is unapologetically a systems guy, but he was just as firmly committed to the practice of cultural criticism, and to the development of what he termed a "German philosophical culture." To this end, he wrote about money, art, literature, clothing, women's liberation, space (paging Adrienne!), meals, and the history of philosophy — all of which makes him a perfect poster-boy for the intersection of Modernist literature (or, if you prefer, culture) and theory.
It also tends to make his essays rather messy, and of course Simmel's not traditionally one of the "master thinkers" of the 20th century (unless you ask Jeff Nunokawa); his methods and opinions are a little too idiosyncratic, and many of his conclusions are far too tied to the political and historical circumstances of his time and place (Germany during and preceding the first World War) to be usable in other connections. He goes in big for German nationalism, for one thing, and his conclusions about the differences between "male" and "female culture" are today not much more helpful than the average stand-up comic's. But despite all these flaws, he's a great and inspiring writer, I think, and, more perhaps than his contemporaries, seems like a Modernist himself in his passionate concern with culture from a slight remove, and always with a weird mixture of missionary zeal and caution.
Appropriately, then, I find the Simmelian concept that's having the most afterlife with me is that of the "cultural series," which he formulates most cogently in this passage from his 1911 essay "On the Essence of Culture":
"We are accustomed automatically to label as cultural values the great series of artistic and moral, scientific and economic achievements. Perhaps they all are; but they are certainly not so by virtue of their purely objective, as it were autochthonous significance. The cultural significance of any particular achievement is by no means equivalent to its significance within its own series as determined by its specific nature and purpose. For example, a work of art is subject to quite different criteria and norms when considered within the sphere of art history or aesthetics, than when its cultural value is involved.
"Each of these great series can be regarded on the one hand as an end in itself, so that each individual member of them constitutes a value which is proven directly by being enjoyed and giving satisfaction. On the other hand, they can all also be included in the cultural series, i.e. considered in respect of their significance for the overall development of individuals in society at large. Standing on their own ground, all these values resist inclusion in the cultural series. A work of art aspires only to perfection as measured by purely artistic criteria … Their contribution to the development of human personality, i.e. their cultural value, is a different matter." (43, italics mine)
This is an extremely useful encapsulation of the problems swirling around l'art pour l'art and the historical efficacy of art and literature which converge so noisily and excitingly in the Modernism of the 1910s and 20s. What's important here, for me, is not that Simmel synthesizes the approaches but that he insists on their fundamental incommensurability. Despite the enormous differences in their writing styles and philosophical allegiances, I actually detect a lot of Jacques Derrida in Simmel: a similar insistence on irreducibility, the impossibility of either incorporating art into culture "without remainder" or of separating the two spheres completely and conclusively.
Without digging too deep, I think it'll be obvious that Simmel's view of culture as a multiply divided sphere has resonance for the Modernists and their situations. Marianne Moore's "Poetry" comes to mind first: "I, too, dislike it: there are things that are important beyond all this fiddle. / Reading it, however, with a perfect contempt for it, one discovers in / it after all, a place for the genuine." This is saying more than "most poetry is trivial, but some of it is worthwhile": it's saying, at least in its extended context, that "all this fiddle" is what poetry is, and that "the genuine" will never be found unless we can find it within the fiddle. Moore is perhaps more of a liberal humanist than Simmel, but like him she shies away from any claim that "reading poetry will make you a better person." What it will do is make you a better reader of poetry; and with that skill in your back pocket, you're on your own to hunt out the genuine. As Moore ends it: "if you demand on the one hand, / the raw material of poetry in / all its rawness and / that which is on the other hand / genuine, you are interested in poetry."
The distinction, then, is between "artistic and moral, economic and scientific achievements" — each of which we must preserve in their own distinctness from the others — and what these achievements are for, the use-value of culture as it were. One could say that Pound and Eliot's problem was that they tried to ignore this distinction, to collapse the multiplicity of cultural series into one epic narrative of civilization's decline (and potential rebirth), though I think Eliot was a lot more tortured by the aporia than Pound was.
Lastly, I'll say that part of why this "cultural series" idea appeals to me has something to do with the process of reading for Generals itself. Following the cultural series that is "Modernism" — let's leave aside the subseries "American," "British," and "French" for now — is not exactly equivalent to following that of "literature," or "history," or even "poetry." Each series includes some of the same materials, perhaps even with the same interpretations placed on them, but the important part is that they reach them and proceed from them in decidedly different ways. The path that leads to Eliot from "French Symbolism" is related but fundamentally foreign to the path that leads to him from "late Victorianism"; and what to make of the longer trajectory that gets us there from Dante, or the Metaphysicals, or, as Edmund Wilson suggests, from New England Protestantism? When dealing with such lengthy series — Derrida, or Mallarmé, might call them "chains" — it's probably best not to try to over-intertwine them, or lay them out parallel, for fear of distorting or destroying the integrity of the individual series itself. But in order for the act of criticism to be worth performing at all, there needs to be some kind of space where they can come together, or where you can put them together, at least provisionally. That space, for Simmel, is called "culture" (and for Habermas, the "public sphere"?). For us, maybe "theory."
Of course all of this (my pontification, not Simmel's) is to some extent graduate-student navel-gazing (hello if you've made it this far!): the thing is to get on with your work, learn as much as you can about context in the broadest sense, and use what seems relevant in any given connection (the pragmatist approach). But I guess what I want to affirm here is why Simmel is now sort of a hero of mine: he's a proud non-specialist who resists being a universalist, but is nonetheless far from a nihilist. (As a matter of fact, the other philosopher he reminds me of most is Nietzsche.) The problem for Simmel was that there was too much stuff in the modern world — too many material objects, too many people, too much knowledge, theory, art, culture; not too much because in and of itself excess is deplorable (that's more the Puritan consciousness as diagnosed by Simmel's mentor Max Weber), but too much for any individual subject, even a highly educated and "cultivated" one, to absorb for him or herself. (In this attitude we might see a hint of self-pity; Simmel can be read as sort of a Modernist Henry Bemis.) Thus he saw most trends in modern life and thought as a way to either screen out or superficially synthesize the overwhelming plethora of series existing all around us.
It's this awareness of plethora, and strange mix of caution and exhilaration in the face of it, that makes me want to put Simmel forward as the model for a kinder, gentler critical theory: one which does not insist on a forcing of connections across cultural fields, or anyway recognizes the eternal difficulties of such connections,* but which allows that these connections are possible and desirable, are something which all but the most blinkered and limited human beings will want to do. And which, along with whatever expert authority it claims for itself and its own interpretations, maintains a trust in the capacity of other people to make these connections for themselves, given proper access to a wide enough variety of series, and enough time.
(* I'm dancing around the figure of Adorno here, who strikes me in many ways as Simmel's evil twin. )