What is the primary distinction between modern communism and socialism? karl marx conceptualized socialism as a response to capitalism, but communism only came into being after the russian revolution. socialism is a theoretical ideal proposed by economists but never put into practice, and communism was the dominant economic system of the 1900s. communism is a particular form of socialism practiced today in many modern democracies in western europe. socialism allows for some private ownership of property and businesses, but communism has the government hold all property.