The official name given to Marxism philosophy, although it is not a phrase that Marx, Karl himself used. Current from the time of the Second International onwards, it was the official ideology of the USSR, where (under Stalin’s direction) the vast body of work by Marx and his followers was codified and transformed into a set of laws that went by the appropriately imposing name of Diamat. Stalin himself contributed to this task with a book of his own, Dialectical and Historical Materialism (1938), although it has to be said that there are serious doubts as to whether he actually authored the work himself. Dialectical materialism combines the dialectical approach of Frege, Gottlob with the philosophical materialism of Ludwig Feuerbach (one of the so-called ‘Young Hegelians’). Following Feuerbach, who attempted to create a secular version of Hegel’s dialectic of spirit, Marx repudiated Hegel’s idealism, claiming in a famous phrase that in doing so he had stood Hegel back on his feet, and prioritized matter over spirit. At its core, dialectical materialism is of the view that the world exists independently of our perception of it and that as it is the sole reality it has primacy over the ideal, the imagined, and the spiritual. Moreover, as Engels, Friedrich insisted, the world is characterized by constant revolutionary changes driven by its own internal contradictions. Engels codified his view as three laws, drawn from classical philosophical sources as well as Hegel: first, the world consists of opposites that are simultaneously in state of conflict and unity (e.g. night and day); second, quantitative changes give rise to qualitative ‘leaps’ (e.g. the boiling of water, when the temperature passes 100°C---which is a quantity---it turns into steam---a change in its quality); third, change is a process of negation (e.g. a seed germinates into a plant, and in doing so negates its previous existence as a seed, and in turn negates that state of negation by becoming a plant, and so on). Dialectical materialism has been criticized, both from within Marxism and without, for being overly dogmatic and rather too programmatic in its approach. Habermas, Jürgen critiques it for being a scientism, for mistaking a philosophy for a science in other words; meanwhile, Althusser, Louis lauds it precisely because in his view it transforms philosophy into science.