After being proclaimed dead, there is now a major revival of socialism ideology in the West. But what does socialism mean? This book shows that it is irretrievably associated with common ownership. The twentieth-century experience of comprehensive national planning with state ownership has been disastrous, and in no case has democracy endured within large-scale socialism. This volume explains why. The alternative socialist option of worker-owned cooperatives must accept a major role for markets that many socialists reject. Further experiments in that direction must be subordinate to higher principles of liberal solidarity, involving a mixed market economy with a welfare state.