On the basis of sociological research focused on actions and appreciations of ‘social policy’ actors, this chapter contends that, apart from the powerful constraint of macroeconomic governance, the main governance instrument has been hard law, even in an area where member states are deemed to have retained most of their jurisdiction. The sociological material is systematically cross-checked with legal literature and with material drawn from 26 EU law specialists’ interviews. The authors focus on the relationship between EU law and ‘social law’ (social protection, labour law and social services). The main finding is the confirmation of the jeopardisation of systems of social protection in the ‘old member states’. On the other hand, though, the Court of Justice of the European Union and the Commission have been able to display continual advances on the subject of ‘fundamental rights’, thus producing key sources of legitimacy among various actors. With the classically documented support of big business and corporations, and the active support of NGOs in favour of expanding individual fundamental rights, the on-going dynamics of EU law seem to lead inexorably to the demise of the late 19th century-born systems of social protection, as F. Scharpf argues. This deterministic analysis, however, does not take into account the current uncertainties about the role of actors.