Ideology is a process accomplished by the so-called thinker consciously, it is true, but with a false consciousness. The real motive forces impelling him remain unknown to him; otherwise it simply would not be an ideological process. Hence he imagines false or seeming motive forces. Because it is a process of thought he derives its form as well as its content from pure thought, either his own or that of his predecessors. He works with mere thought material, which he accepts without examination as the product of thought, and does not investigate further for a more remote source independent of thought; indeed this is a matter of course to him, because, as all action is mediated by thought, it appears to him to be ultimately based upon thought.
The historical ideologist (historical is here simply meant to comprise the political, juridical, philosophical, theological – in short, all the spheres belonging to society and not only to nature) thus possesses in every sphere of science material which has formed itself independently out of the thought of previous generations and has gone through its own independent course of development in the brains of these successive generations. True, external facts belonging to one or another sphere may have exercised a co-determining influence on this development, but the tacit presupposition is that these facts themselves are also only the fruits of a process of thought, and so we still remain within that realm of mere thought, which apparently has successfully digested even the hardest facts.
It is above all this semblance of an independent history of state constitutions, of systems of law, of ideological conceptions in every separate domain that dazzles most people. If Luther and Calvin “overcome” the official Catholic religion or Hegel “overcomes” Fichte and Kant or Rousseau with his republican Contrat social indirectly “overcomes” the constitutional Montesquieu, this is a process which remains within theology, philosophy or political science, represents a stage in the history of these particular spheres of thought and never passes beyond the sphere of thought. And since the bourgeois illusion of the eternity and finality of capitalist production has been added as well, even the overcoming of the mercantilists by the physiocrats and Adam Smith is accounted as a sheer victory of thought; not as the reflection in thought of changed economic facts but as the finally achieved correct understanding of actual conditions subsisting always and everywhere – in fact, if Richard Coeur-de-Lion and Philip Augustus had introduced free trade instead of getting mixed up in the crusades we should have been spared five hundred years of misery and stupidity.