The belife in progress is a core liberal assumption. But it is also a point of debate among liberals. How much progress? Scientific and technological for sure, but also social and political? What are the limits of progress? Are there any limits? Progress for whom? A small number of liberal countries or the entire world? The scope and degree of liberal optimism as regards progress has fluctuated over time. Many early liberals were inclined to be thoroughly optimistic; we have also noted the surge of liberal optimism after the end of the Cold War , propelled by the notion of 'the end of history'based on the defeat of communism and the expected universal victory if liberal democracy. However, the terrorist attacks in New York and Washington of 11 september 2011, followed by the attacks in madrid,London,and elsewhere, are a setback for liberal optimism.