Man still needs to undergo a complete spiritual rebirth in his attitude towards his work, freed from the direct pressure of his social environment, though linked to it by his new habits. That will be communism.
The change in consciousness will not take place automatically, just as it doesn't take place automatically in the economy. The alterations are slow and are not harmonious; there are periods of acceleration, pauses and even retrogressions.

Man and Socialism in Cuba (1965)