Full Idea
In general ideologists inevitably put the thing upside-down, and regard their ideology both as the creative force and as the aim of all social relations, whereas it is only an expression and symptom of these relations.154
Gist of Idea
Ideologists think their theories drive social forces, when they are actually mere symptoms
Source
Karl Marx (Collected works (w Engels) - 50 vols [1860], Vol 5: 419-20), quoted by Jaime Edwards/Brian Leiter - Marx 5.1
A Reaction
Marx can't seem to decide whether ideologists are actively duplicitous, or merely misguided. I presume the latter, since Marxists tend to assume that no one (apart from Marxists?) is aware of their own biases.
Book Reference
Edwards,J/Leiter,B: 'Marx' [Routledge 2025], p.154