June 12, 2018:

"The Materiality of Ideology" is part of Althusser's reformulation. Ideologies aren't ideas, they're books and speeches and sermons, institutions and rituals, habits and practices which produce ideas. Practices are the key. Althusser: "...the existence of the ideas in which [an individual subject] believes is material in that his ideas are his material acts inserted into material practices regulated by material rituals which are themselves defined by the material ideological apparatus from which (hardly by accident!) his ideas derive." Institutions are crucial for the reproduction of ideologies: they materialize and propagate the ideologies on which they're based. A school, a church, the Pentagon: institutions and social practices materialize ideology as part of the reproduction of the social formation. Both its material conditions and its ideologies must be reproduced for a mode of production or a social formation to carry on.