Karl - Marx affirmed that societies evolved as well as towards the human species, that is, that clearly one must go through several periods and stages that take their time, there can not be an evolution either ignoring or accelerating the stages that nature itself forces you to have, according to the theoretical socialisms and based on some sociological and anthropological principles; After a society reaches the top of the capitalist system it passes to socialism or communism.
Given the above, it means that a society reaches the top of the capitalist system and passes to the socialist system in an EVOLUTIVE way and not in a TAXY or FORCEED way ... There lies the difference between what is socialism theoretically speaking and what Karl - Marx ... Marx says that you must take the means of production, become common good and then NATUALLY people adapt ... BOTH force and impose something on human consciousness and then expect a natural reaction of adaptation. The previous thing violates the theoretical principle of the socialism but it is the socialism seen from the point of view of Marx
The clearest example that socialism can be achieved in an evolutionary way (Without forcing) is how the business models of Google, facebook and finally crowfunding provide services completely free to billions of people in the world. And I will clarify, services that 100% capitalist companies charged for providing them, for example: Telephone calls, platform for the creation of free pages, platform for services to free companies, etc. etc.
Another example of the theoretical socialist principle and not Marxist.
What does it matter what color the cat is, but who marries mice
President of China Deng Xiaoping when asked about the economic opening as a country with a communist political system ....