From 1885 to 1889 Shaw attended the fortnightly meetings of the British Economic Association; it was, Holroyd observes, "the closest Shaw had ever come to university education." This experience changed his political ideas; he moved away from Marxism and became an apostle of gradualism.[48] When in 1886–87 the Fabians debated whether to embrace anarchism, as advocated by Charlotte Wilson, Besant and others, Shaw joined the majority in rejecting this approach.[48] After a rally in Trafalgar Square addressed by Besant was violently broken up by the authorities on 13 November 1887 ("Bloody Sunday"), Shaw became convinced of the folly of attempting to challenge police power.[49] Thereafter he largely accepted the principle of "permeation" as advocated by Webb: the notion whereby socialism could best be achieved by infiltration of people and ideas into existing political parties.[50]