The preceding chapters of this book have shown that, correctly understood, social democracy is far more than the defender of particular policies or values such as the welfare state, equality, or solidarity. Nor is it merely watered-down Marxism or bulked-up liberalism, but rather, at least as originally conceived, a distinctive ideology and political movement all its own.

Social democracy's foundations were laid in the late nineteenth century when Eduard Bernstein and other democratic revisionists began attacking the main pillars of orthodox Marxism, historical materialism, and class struggle, and arguing for an alternative based on new principles, the primacy of politics, and cross-class cooperation. These democratic revisionists at first insisted that they were merely “revising” or “updating” Marxism, but here it was their fiercest critics – the defenders of orthodoxy – who saw more accurately what the revisionists themselves were loath to admit: that they were actually replacing Marxism with something entirely different. Just what that thing was became clear a generation later. In response to the challenges of the interwar years, socialist dissidents across Europe built on the principles laid out by Bernstein and others and developed a whole new practical program for the left based on state control of markets, communitarianism, and a “people's party” strategy. By the 1930s, in other words, the project begun by the democratic revisionists in the nineteenth century had been completed: A new political movement that embodied its own principles and policies had been born.