This document outlines several key concepts related to socialism, including:
1) Revisionist Marxism which critiqued Marx's failed predictions about capitalism and argued that capitalism has proven more resilient.
2) Keynesian social democracy which advocated for a mixed economy, economic management of capitalism to ensure full employment, and welfare states to promote equality through redistribution.
3) The tension within social democracy between commitments to equality and economic efficiency, which became highlighted during the 1970s recession and led to the collapse of traditional social democracy in places like the UK.