Why did Karl Marx believe that now was the time for a revolution, as opposed to any time previously? ...

Using the argument from Hegelian dialectics, Marx looked at the concept of historical inevitability, believing that history could be seen as a series of class struggles. Previously, there had been struggles between serfs and lords, slaves versus owners, and now the proletariats versus the capitalists. What made the present time different was the presence of an urban, industrialized working class in contrast to the new system of capitalism. As such, workers were now suffering from alienation of their labor, resentment of oppression and exclusion from the means of production, and the growing discrepancy in wealth built on the backs of their labor. Hence, Marx argued, the proletariat would inevitably rise up in revolution against the bourgeoisie, strip them of their wealth and create a just and egalitarian society.