system
Given the following post, respond as if you're commenting on Reddit:
human
Marx's "materialism without matter"

In *The Philosophy of Marx,* Balibar states that "Marx's materialism has nothing to do with a reference to *matter*" and calls it a "materialism without matter". What exactly is meant by this?
gpt
We’ll, ask yourself this: what does Marx actually do? Answer: he relates cultural productions back to their “material” ground, by which is meant very specifically the productive forces and organisation of *labour* in a given society. Henceforth, theories of all sorts, such as conceptions of how the economy works, what justice is, how society should be organised etc. are traced back to their material ground and unmasked as products of ideology. The “matter” here refers to the economy, it is not an ontological thesis about what kind of stuff ultimately makes up the world. 

There is a great reading of the triad Kant-Hegel-Marx in Habermas’ *Knowledge and Interest* (first 50 ish pages) in which Habermas basically argues that the notion of labour, in its historical specificity, comes to take the role of a historicised version of transcendental subjectivity in Marx. The world is the correlate of a synthesis, but not the theoretical synthesis of a timeless subject, but the concrete productive synthesis of a concrete historical community. Before we know the world, we work on it, and the world as shaped by our labour is what grounds our theoretical dealing with it. 

The silliest thing you can do is fall into the trap of taking materialism to be an ontological thesis in the first place. This is often done in shallow polemics against “idealism” where idealism can mean the most ordinary things. Some Marxists even end up forced to admit that “ideas” can have an influence on the world (what could be more obvious) but only because ideas are themselves “material” (embodied as brain patterns etc.). Such arguments are unnecessary because the Marxist criticism of idealism has nothing to do with denying a causal force to “otherworldly” entities.

[I can’t guarantee that this is how Balibar himself understands the question but this is one reasonable way of looking at it]

You might also want to look into Alfred Sohn-Rethel’s tracing of the concept of substance back to the emergence of systems of currency in the ancient world (briefly: a coin keeps its identical value throughout all its changes of shape and colour. This, he argues, forms the model for the thought of substance)