Business cycle by Charles Dunoyer, and similar theories, showing signs of influence by Sismondi, were developed by Johann Karl Rodbertus. Periodic crises in capitalism formed the basis of the theory of Karl Marx, who further claimed that these crises were increasing in severity and, on the basis of which, he predicted a communist revolution. Though only passing references in "Das Kapital" (1867) refer to crises, they were extensively discussed in Marx's posthumously published books, particularly in "Theories of Surplus Value". In "Progress and Poverty" (1879), Henry George focused on land's role in crises – particularly land speculation – and proposed a single
The Communist Manifesto of the spectre of communism with a manifesto of the party itself". The first section of the "Manifesto", "Bourgeois and Proletarians", elucidates the materialist conception of history, that "the history of all hitherto existing society is the history of class struggles". Societies have always taken the form of an oppressed majority exploited under the yoke of an oppressive minority. In capitalism, the industrial working class, or "proletariat", engage in class struggle against the owners of the means of production, the "bourgeoisie". As before, this struggle will end in a revolution that restructures society, or the "common ruin of the contending