Marx’s ability to break down other ideologies and study the reasoning for their ineffectiveness, was another major source. Marx analyzed ideologies like conservative socialism, its downfall and why it couldn't maintain itself through communism to determine whether communism could really be effective under the stress of capitalism. History is used throughout and throughout The Communist Manifesto to valid and thoroughly explain Karl Marx’s arguments. Marx followed the evolution of capitalism after the feudal system and through the duration of the Modern Industrial Era to form his premises and based most of his logic upon those findings.
Lastly, the final source Marx used throughout The Communist Manifesto, was simply his own logical reasoning