This paper argues that science and technology have been closely linked to the crisis of social democracy, as this political culture drew strength from the optimism about scientific progress. The paper reviews the literature on the decline of social democracy to assess how its role has been perceived. Then, it describes the evolving impact of scientific issues on the programs of PES in the 21st century, as it was central to new policies of economic intervention to build human capital. Finally, it shows elements of continuity with the rhetoric and policies of the Cold War era, despite attempts by supporters of the Third Way to present it as completely new.