Capitalism is a necessary but barbaric pre-requisite for socialism. Marxism, from its birth, recognised that capitalism creates the foundations for socialism. As the most dynamic system ever, capitalism creates a world in which scarcity would be abolished.

In pre-capitalist societies crisis were accompanied by underproduction. Capitalist crisis is accompanied by overproduction - more wealth is produced than can be absorbed by the market. The consequences - starvation, war, disease - might be the same, but the causes are very different.

People's needs could, potentially be met. But this potential is constantly undercut because needs are subordinated to the profit drive.

Fortunately, capitalism also creates the second pre-requisite for socialism - its 'gravediggers'. As Marx wrote:

"With the development of industry the working class not only increases in number - it becomes more concentrated in greater masses, its strength grows."

This is not just a feature of capitalism's past, of the industrial revolution, or of newly industrializing countries such as China. Half of Britain's workers are today employed in workplaces of over 250 people. Giants such as Heathrow airport (workforce 32,000) dwarf many of the factories of the past.

This growth and concentration of the working class opens up new possibilities. When earlier oppressed classes rose up, they could seize the productive forces of society and continue to use them in the old way. Peasants would revolt, kill their landowners, seize the land and divide it among themselves to farm.

For workers under capitalism this route is closed off. For instance, its not possible to divide a place like Heathrow airport 32,000 ways or parcel out a supermarket. When workers take control they will be forced to develop collective, democratic solutions to the problems they face. This is the essence of Marxism - it heralds a new world built from below by workers themselves.