Moreover, Lenin’s chief amendment to Marxism–“the vanguard party”–finds good intellectual warrant in the Founder himself. …there exists a deep connection between Marx’s idea of Communism as conscious, rational mastery over mankind’s collective fate and Lenin’s idea of the Party as the controlling vanguard of the spontaneous mass movement.
Signet Classics edition of The Communist Manifesto, by Karl Marx and Friedrich Engels, with an Introduction by Martin Malia and a New Afterword by Stephen Kotkin, p 29