final aim and necessary result of the development of the productive forces in modern society. All recorded history hitherto has been a history of class struggle, of the succession of the rule and victory of certain social classes over others." According to Paul Kellogg, there is "some considerable controversy" regarding "the place of Frederick Engels in the canon of 'classical Marxism'". While some such as Terrell Carver dispute "Engels' claim that Marx agreed with the views put forward in Engels' major theoretical work, Anti-Dühring", others such as E. P. Thompson "identified a tendency to make 'old Engels into a whipping boy, and to impugn him any sign that once chooses to impugn subsequent Marxsisms'". Tristram Hunt argues that Engels has become a convenient scapegoat, too easily blamed for the state crimes of Communist regimes such as China, the Soviet Union and those in Africa and Southeast Asia, among others. Hunt writes that "Engels is left holding the bag of 20th century ideological extremism" while Karl Marx "is rebranded as the acceptable, post–political seer of global capitalism". Hunt largely exonerates Engels, stating that "[i]n no intelligible sense can Engels or Marx bear culpability for the crimes of historical actors carried out generations later, even if the policies were offered up in their honor". Andrew Lipow describes Marx and Engels as "the founders of modern revolutionary democratic socialism". While admitting the distance between Marx and Engels on one hand and Joseph Stalin on the other, some writers such as Robert Service are less charitable, noting that the anarchist Mikhail Bakunin predicted the oppressive potential of their ideas, arguing that "[i]t is a fallacy that Marxism's flaws were exposed only after it was tried out in power. [...] [Marx and Engels] were centralisers. While talking about 'free associations of producers', they advocated discipline and hierarchy". Paul Thomas, of the University of California, Berkeley, claims that while Engels had been the most important and dedicated facilitator and diffuser of Marx's writings, he significantly altered Marx's intents as he held, edited and released them in a finished form and commentated on them. Engels attempted to fill gaps in Marx's system and extend it to other fields. In particular, Engels is said to have stressed historical materialism, assigning it a character of scientific discovery and a doctrine, forming Marxism as such. A case in point is Anti-Dühring which both supporters and detractors of socialism treated as