Marx and Engels' beliefs about the nature of society and politics are summed up in the Communist Manifesto, which states that "the history of all previously existing society is the history of class battles." They also briefly discuss their theories on how socialism would eventually replace the capitalist society of the moment. The authors of the Manifesto urge the "forceful overthrow of all existing socioeconomic conditions" in the final sentence, which served as a call for communist revolutions all across the world. Along with Marx's Capital, Volume I, The Communist Manifesto was included to UNESCO's Memory of the World Program in 2013. Marx outlined the foundation of his ideology and revolutionary agenda in this political pamphlet.