This paper traces the philosophical, political, sociological and economic underpinning for the advocacy by socialists of progressive taxation, from the Communist Manifesto to recent supporters of tax justice campaigns. Socialists’ attitudes to taxation have been tied to their primary aim of socialisation of the ownership of the means of production, reflecting the view that inequality and exploitation are inherent in capitalism, which rests on private property enforced by state power. Communism, as developed particularly by Marx and Engels, aimed to transcend capitalism and end the separation of the state from civil society, by the socialisation of property, including through progressive taxation. Marx’s view in Capital volume 3 that the emergence of large scale enterprises already entailed the ‘abolition of capital as private property within the framework of capitalist production itself’, when it was published in 1894 became central to the debates among German socialists (Liebknecht, Kautsky, Bernstein and Luxemburg), and the Austro-Marxists (Renner, Hilferding), but socialists split when graduated direct taxes were introduced to help fund the welfare-warfare state. Goldscheid’s outline for a social science of the state centred on fiscality underpinned his radical and influential wartime proposals to finance the socialisation of large corporations through taxes on capital. However, the attempts to implement this in the brief revolutionary moments of 1919 largely failed, while in Russia the revolutionary momentum led to expropriation and state ownership. Goldscheid’s concept of the ‘fiscal state’ was revised by Schumpeter as the ‘tax state’, which he viewed as depending on the continuation of the ‘free’ economy and entrepreneurship, though he accepted that in the long run capitalism would give way to socialism, with the growing demands for public expenditure and the emergence of new ideas about property. Schumpeter’s perspective has provided a basis for critiques of the limitations of the tax state, including by neo-Marxists such as O’Connor, but Goldscheid’s linking of taxation to the socialisation of corporate capital has been neglected. With the ‘mixed economy’ fiscal policy became dominated by Keynesianism, socialist variants of which argued that disparities of wealth generate growing inequality, and proposed tax measures for social ownership and equalisation of property, notably from James Meade, and most recently Anthony Atkinson and Thomas Piketty. Marx’s vision of transcending capitalism through the socialisation of property and the merger of civil society and the state has proved a much longer process, with successive stages in which capitalism has become more ‘socialised’, in different ways. The enormous growth of taxation and state expenditure in the twentieth century reflects major transformations in both the state and its relationship with civil society, in which the ‘fiscal state’, including the state’s role in finance, remains central.