This chapter outlines how Marx and Engels resolved classical political economy’s major conundrums to produce their penetrating analysis, and indictment, of capitalism as the contradictory, and thus crisis-prone, production of value at the intersection of the vertical, inter-class, axis of exploitation and the horizontal intra-class axis of competition. It shows how the neoclassical economics emerged, how fundamentally it was opposed to Marxism and how later Marxists who sought reconciliation with it produced ‘Marxist economics’. The chapter focuses on Marx and Engels’s real understanding of capitalism as contradictory value production to understand it as constituting not an ‘economy’, separate from state and society, harmonious and eternal, but as a contradictory dynamic that must deform society, impose contradictory demands on it in all the realms it must modify to secure its existence. It then examines how the state must manage these contradictions to ensure capitalism’s continued existence and how that management makes capitalism as value production itself historical.