The change in the Founding Contract that political leaders initiated on 11 February 2010 put great pressure on the legal set-up of the euro that remained largely unaffected. When the European Court of Justice had to rule on the actions to which the change had given rise it consequently found itself between a rock and a hard place. It was not in a position to strike down actions that had been crucial to the single currency’s survival. Yet, in order to approve of them it had to engage in a Herculean struggle with the law that still largely reflected a stability conception from the past. This chapter examines this approval. Two cases are central: Pringle and Gauweiler. Both cases ultimately turned around the question whether and to what extent the law can accommodate the currency union’s new stability conception, characterized by the need to protect financial stability. Most of the Court’s reasoning in these cases is sound or, where it is strained, could have been justified through the use of different arguments. At one crucial point, however, the Court encounters the limits of what can be justified through legal reasoning alone.