It scarcely needs proof that there is not the slightest possibility of carrying out these tasks in a short period, of accomplishing all this in a few years. Therefore, the dictatorship of the proletariat, the transition from capitalism to communism, must not be regarded as a fleeting period of “super-revolutionary” acts and decrees, but as an entire historical era, replete with civil wars and external conflicts, with persistent organisational work and economic construction, with advances and retreats, victories and defeats. The historical era is needed not only to create the economic and cultural prerequisites for the complete victory of socialism, but also to enable the proletariat, firstly, to educate itself and become steeled as a force capable of governing the country, and, secondly, to re-educate and remould the petty-bourgeois strata along such lines as will assure the organisation of socialist production.

• Stalin

it is only possible to achieve real liberation in the real world by employing real means, that slavery cannot be abolished without the steam-engine and the mule and spinning-jenny, serfdom cannot be abolished without improved agriculture, and that, in general, people cannot be liberated as long as they are unable to obtain food and drink, housing and clothing in adequate quality and quantity. “Liberation” is an historical and not a mental act, and it is brought about by historical conditions, the development of industry, commerce, agriculture, the conditions of intercourse.

• Karl Marx, “The German Ideology”