In 1848, the same year that Mill published his magnum opus, a much smaller but equally important pamphlet was published: The Communist Manifesto. Written by Karl Marx and his close friend Friedrich Engels, both members of the Communist League, the manifesto articulated a philosophy of history in which communist revolution was not only desirable but also inevitable.

Although they were close friends, Marx and Engels could not have been more different in their personalities, appearances, or personal histories. Engels, the son of a narrow-minded German manufacturer, went to work at his father’s textile business in Manchester at an early age. He began reading the radical literature of the time, noting how the city’s pleasant façade hid an underworld where workers lived in despair, hopelessness, and brutality. He published his findings, arguing that the great English economists were apologists for the existing order, which attracted the attention of Karl Marx, who was then editing a philosophy magazine in Paris.

Marx came from a mildly radical family of prosperous Jews who later converted to Christianity. Although his father hoped he would study law, Marx found inspiration in the then-controversial ideas of Wilhelm Frederic Hegel, who argued that the Enlightenment’s focus on reason and individualism weren’t the only ways of knowing; humanity should be seen as part of whole, with each individual evolving toward a melding of minds that would create eventual human unity.