 Cohen identifies a number of explanatory connections between the “ensembles” that appear in Marx’s “1859 Preface”: the productive forces; the relations of production; and the superstructure. Consider an example involving the first two of those ensembles. The productive forces are those facilities and devices—means of production (including tools, raw materials, and premisses) and labour power (including strength, skill, and technical knowledge)—used to productive effect in the process of production. They are said, on this account, to grow in power over the course of human history. And the relations of production—the sum total of which are said to constitute the economic structure (or “base”) of a given society—are the relations of power that people enjoy, or lack, over those forces, over means of production and labour power (G. Cohen 1988: 4).