Economic Problems of Socialism in the USSR

"One of the distinguishing features of political economy is that its laws, unlike those of natural science, are impermanent, that they, or at least the majority of them, operate for a definite historical period, after which they give place to new laws. However, these laws are not abolished, but lose their validity owing to the new economic conditions and depart from the scene in order to give place to new laws, laws which are not created by the will of man, but which arise from the new economic conditions." - Stalin