Marx and Engels ignored utterly the many and varied assaults that Bakounin made upon their theoretical views. They were not the least concerned over his attacks upon _their_ socialism. They had not invented it, and economic evolution was determining its form. It was not, indeed, until 1875 that Engels deals with the tendencies to State socialism, and then it was in answer to Dr. Eugene Duehring, _privat docent_ at Berlin University, who had just announced that he had become "converted" to socialism. Like many another distinguished convert, he immediately began to remodel the whole theory and to create what he supposed were new and original doctrines of his own. But no sooner were they put in print than they were found to be a restatement of the old and choicest formulas of Proudhon and Bakounin. Engels therefore took up the cudgels once again, and, no doubt to the stupefaction of Duehring, denied that property is robbery,[48] that slaves are kept in slavery by force,[49] and that the root of social and economic inequality is political tyranny.[50] Furthermore, he deplored this method of interpreting history, and pointed out that capitalism would exist "if we exclude the possibility of force, robbery, and cheating absolutely...." Furthermore, "the monopolization of the means of production ... in the hands of a single class few in numbers ... rests on purely economic grounds without robbery, force, or any intervention of politics or the government being necessary." To say that property rests on force "_merely serves to obscure the understanding of the real development of things_."[51] I mention Engels' argument in answer to Dr. Duehring, because word for word it answers also Bakounin. Of course, Bakounin was a much more difficult antagonist, because he could not be pinned down to any systematic doctrines or to any clear and logical development or statement of his thought. Indeed, Marx and Engels seemed more amused than concerned and simply treated his essays as a form of "hyper-revolutionary dress-parade oratory," to use a phrase of Liebknecht's. They ridiculed him as an "amorphous pan-destroyer," and made no attempt to refute his really intangible social and economic theories.