The subject of this study is: 1) the background of Bernstein revisionism, German (and not only German) "cathedra-socialists," English "Fabian society"; Russian populism, "legal Marxism"; 2) the theoretical views of E. Bernstein, their formation and development; 3) criticism of Bernsteinism by his Marxist contemporaries in the late XIX - early XX centuries; 4) the development of Bernstein revisionism by theorists of the Social Democratic parties of the middle and second half of the 20th century; 5) Eurocommunism, or "Western Marxism," as part latent, part open revision of Marxism and mainly the so-called Marxism-Leninism. Since the revision of any scientific theory, no matter how high its status, is a normal, generally accepted research procedure, to the extent that it is qualified as, in principle, incompatible with the teachings of K. Marx and F. Engels, is evidence of dogmatism inherent in Marxism and the beginning of its dogmatization by Marxist parties.