thumb|left|upright|Soviet Union stamp commemorating the 100th anniversary of the Manifesto In contrast, critics such as revisionist Marxist and reformist socialist Eduard Bernstein distinguished between "immature" early Marxism—as exemplified by The Communist Manifesto written by Marx and Engels in their youth—that he opposed for its violent Blanquist tendencies and later "mature" Marxism that he supported.Steger, Manfred B. The Quest for Evolutionary Socialism: Eduard Bernstein And Social Democracy. Cambridge & New York: Cambridge University Press, 1997. pp. 236–37. This latter form refers to Marx in his later life seemingly claiming that socialism, under certain circumstances, could be achieved through peaceful means through legislative reform in democratic societies.Micheline R. Ishay. The History of Human Rights: From Ancient Times to the Globalization Era. Berkeley & Los Angeles: University of California Press, 2008. p. 148. Bernstein declared that the massive and homogeneous working-class claimed in the Communist Manifesto did not exist, and that contrary to claims of a proletarian majority emerging, the middle-class was growing under capitalism and not disappearing as Marx had claimed. Marx himself, later in his life, acknowledged that the Petite bourgeoisie was not disappearing in his work Theories of Surplus Value (1863). The obscurity of the later work means that Marx's acknowledgement of this error is not well known.Michael Harrington. Socialism: Past and Future. Reprint edition of original published in 1989. New York: Arcade Publishing, 2011. pp. 249–250. George Boyer described the Manifesto as "very much a period piece, a document of what was called the 'hungry' 1840s"..
thumb|left|upright|Soviet Union stamp commemorating the 100th anniversary of the Manifesto In contrast, critics such as revisionist Marxist and reformist socialist Eduard Bernstein distinguished between "immature" early Marxism—as exemplified by The Communist Manifesto written by Marx and Engels in their youth—that he opposed for its violent Blanquist tendencies and later "mature" Marxism that he supported.Steger, Manfred B. The Quest for Evolutionary Socialism: Eduard Bernstein And Social Democracy. Cambridge & New York: Cambridge University Press, 1997. pp. 236–37. This latter form refers to Marx in his later life seemingly claiming that socialism, under certain circumstances, could be achieved through peaceful means through legislative reform in democratic societies.Micheline R. Ishay. The History of Human Rights: From Ancient Times to the Globalization Era. Berkeley & Los Angeles: University of California Press, 2008. p 148. Bernstein declared that the massive and homogeneous working-class claimed in the Communist Manifesto did not exist, and that contrary to claims of a proletarian majority emerging, the middle-class was growing under capitalism and not disappearing as Marx had claimed. Marx himself, later in his life, acknowledged that the Petite bourgeoisie was not disappearing in his work Theories of Surplus Value (1863). The obscurity of the later work means that Marx's acknowledgement of this error is not well known.Michael Harrington. Socialism: Past and Future. Reprint edition of original published in 1989. New York: Arcade Publishing, 2011. pp. 249–250. George Boyer described the Manifesto as "very much a period piece, a document of what was called the 'hungry' 1840s".