To overthrow the power of the bourgeoisie and to establish the power of the proletariat in one country still does not signify the full victory of Socialism.
Leon TrotskyCan and must! The proclamation of this new conception of [Joseph Stalin] is closed by the same words, "Such are in general the characteristic features of Lenin's conception of the proletarian revolution." In the course of a single year Stalin ascribed to [Vladimir] Lenin two directly opposed conceptions of the fundamental question of socialism. The first version represents the real tradition of the party; the second took shape in Stalin's mind only after the death of Lenin, in the course of the struggle against "Trotskyism".
Leon TrotskyThe initiative of the Five Year Plan and of the accelerated collectivization belongs entirely to the Left Opposition, in uninterrupted and sharp struggles with the Stalinists. Not having the possibility of occupying myself here with long historical researches, I will limit myself to a single illustration. The Dnieprostroy is considered with right as the highest achievement of Soviet industrialization. Yet [Joseph] Stalin and his followers ([Clim] Voroshilov and others) a few months before the beginning of the work were decided opponents of the Dnieprostroy plan.
Leon Trotsky