His materialism exposes another illusion of both religion and the state, “The Illusion of Autonomous Origin,” which relates to the conditioned character of religious and political beliefs and practices.
Marx writes that,
[t]he ideas of the ruling class [or classes] are in every epoch the ruling ideas, i.e. the class which is the ruling material force of society is at the same time its ruling intellectual force. The class which has the means of material production at its disposal, has control at the same time over the means of mental production… The ruling ideas are nothing more than the ideal expression of the dominant material relationships (Marx, Selected Writings, p.176).When we lose sight of the contingent and conditioned nature of ideas and practices, which according to Marx express the dominant ordering of relationships between classes, we are trapped in The Illusion of Autonomous Origin. We are, in other words, unaware of the way in which ideas and practices are expressions of certain “ideologies.”
The term “ideology” refers to ‘any interpretation of history which is based on… ideas divorced from the social-economic realities in which those ideas originate’ (Louis Dupre, The Philosophical Foundations of Marxism, p.146). Further than this, however, these interpretations are characterised not only by ‘our unawareness of their origin in social conditions’ – The Illusion of Autonomous Origin – but by our ignorance of ‘the part they play in maintaining or altering those conditions’ (Leszek Kolakowski, Main Currents of Marxism, vol.1, p.154) – what Westphal calls “The Illusion of Neutrality.”
That we are unaware of the social impact of ideas and practices is the key to the operation of ideology, ‘[f]or to the degree that [The Illusion of Neutrality] prevails the victims of political power will feel less resentful and the perpetrators of political power will feel less guilty’ (Westphal, Suspicion and Faith, p.160). The Illusions of Overcoming the World and of Autonomous Origin therefore function to support the central illusion at work in ideology, the Illusion of Neutrality, and together these illusions act to mask the fact that ideology is ‘the imaginary relationship of individuals to their real conditions of existence’ (Louis Althusser, "Ideology and the State," p.162) and forestall questions from both the perpetrators and victims of political power about its injustices.
For Marx, both religion and the state perform this ideological function, serving to mask the contingent ordering of society that benefits some whilst oppressing others.