 In the sketch of The German Ideology, many of the key elements of historical materialism are present, even if the terminology is not yet that of Marx’s more mature writings. Marx’s statement in the “1859 Preface” renders something of the same view in sharper form. Cohen’s reconstruction of Marx’s view in the Preface begins from what Cohen calls the Development Thesis, which is pre-supposed, rather than explicitly stated in the Preface (Cohen 1978 [2001]: 134–174). This is the thesis that the productive forces tend to develop, in the sense of becoming more powerful, over time. The productive forces are the means of production, together with productively applicable knowledge: technology, in other words. The development thesis states not that the productive forces always do develop, but that there is a tendency for them to do so. The next thesis is the primacy thesis, which has two aspects. The first states that the nature of a society’s economic structure is explained by the level of development of its productive forces, and the second that the nature of the superstructure—the political and legal institutions of society—is explained by the nature of the economic structure. The nature of a society’s ideology, which is to say certain religious, artistic, moral and philosophical beliefs contained within society, is also explained in terms of its economic structure, although this receives less emphasis in Cohen’s interpretation. Indeed, many activities may well combine aspects of both the superstructure and ideology: a religion is constituted by both institutions and a set of beliefs.