In the early 1970s in South Africa two developments coincided. Workers in the port city of Durban struck, triggering a union movement which was crucial in defeating apartheid and which remains the society’s largest organized force. And radical scholars began to analyse apartheid as a system of class domination. The two were related, for the scholarship helped convince middle-class radicals to join the union movement. It also made democracy and a critique of private economic power key themes for the movement. The relationship between the ideas and the movement show the limits and possibilities of academic influence on social movements.