“what matters is the thread of expression”

From Benjamin, ‘Convolute N’, The Arcades Project.  

Marx lays bare the causal connection between economy and culture. For us, what matters is the thread of expression. It is not the economic origins of culture that will be presented, but the expression of the economy in its culture. At issue, in other words, is the attempt to grasp an economic process as perceptible Ur-phenomenon, from out of which proceed all manifestations of life in the arcades (and, accordingly, in the nineteenth century).

[N1a,6]

From Benjamin, The Author as Producer.

Before I ask: how does a literary work stand in relation to the relationships of production of a period, I would like to ask: how does it stand in them? This question aims directly at the function that the work has within the literary relationships of production of a period.