I've been reading a bunch of Arendt, and, in light of my recent re-reading of Sohn-Rethel, I've noticed something both odd and, I think, revealing about Arendt's understanding of the vita activa--she completely overlooks commodity exchange as a distinctive form of activity.
Arendt's overall project, post-Origins of Totalitarianism, is centered around a rearticulation of active or practical life as of principles and a dignity separate from but equal to that of contemplation. I'm very sympathetic to this project, at least in such broad outlines. I'm especially attracted to her recognition of the fundamental plurality of activities, which sets her apart from all the mythologies of utilitarianism and rational choice action theory. However, I've always been nagged by a sense that her effort to separate out the various modalities of active life--labor, work, action--was itself a bit of a simplification or homogenization. However, nagging doubts do not an assessment make. Now I feel like I'm on somewhat more solid ground. Let me lay out the indicators of the problem:
Arendt's only prolonged discussion of exchange (that I know of) is in the "Work" section of The Human Condition (pp 159-67). The discussion is situated as it is because Arendt thinks that the exchange market is the public sphere corresponding to and growing out of work or fabrication, the making of persistent objects of use or artifacts. In Arendt's words, "homo faber, the builder of the world and the producer of things, can find his proper relationship to other people only by exchanging his products with theirs" (160).
But she immediately introduces a consideration that flagrantly contradicts this proper fit of the market to the artisans as producers. The sentence I just quoted continues by "explaining" this propriety; the artisan finds his proper relation to others in the exchange market "because the products themselves are always produced in isolation" (160-1). This sounds strange, I think, because we immediately think of assembly lines, factories, and cooperation when we think of production. Arendt has an explanation for this--basically, the division of labor within a process of production she associates with labor, the reproduction of life, and the conquest of production by the division of labor is therefore the subordination of work to labor--but I'll leave that aside for now. I think the plausibility of her insistence on the solitude of the artisan can be rescued by reference to such commonplaces as "too many cooks spoil the broth," and the certainty that doing anything "by committee" is sure to be a disaster from the standpoint of the quality of the end result. The work, for Arendt, is characterized by a singleness of intention and attention, and hence the artisan qua artisan is alone.
But for precisely this reason, the people who meet in the market are not artisans qua artisans, as Arendt herself recognizes. "The people who met on the exchange market, to be sure, were no longer the fabricators themselves," she writes; "when homo faber comes out of his isolation, he appears as a merchant and trader and establishes the exchange market in this capacity" (162-3). Therefore, she also claims that exchange value cannot be grounded in any "specific human activity" (164).
So, Arendt, it seems to me, is caught in the uncomfortable position of affirming both that exchange "develops without break and consistently" from "the world of the craftsman and the experience of fabrication" (166) and that this exchange presupposes a change in the personae and a dissociation from any actual activity of making things.
This is where Sohn-Rethel can meaningfully supplement Arendt. The recognition that commodity exchange is a separate mode of activity, and a specific from of human interaction, undermines the assumption that Arendt shares with the utilitarians and economists from whom she so radically diverges otherwise: the assumption that a generalized "utility" can be unproblematically extrapolated from the concrete uses of the objects we make. This presumptive link between use and utility is the unthought ground of modern economics, and exposing the absence of any such link is the ongoing task of the critique of political economy.