The euro area crisis seems to be behind us, but there is an intensive discussion about what can and should be learned from it. The questions are as broad as they are crucial. Do we need more or do we need less Europe? Is the lack of a "political union" a fundamental flaw the currency union will have to overcome—and at what time horizon? Does the euro need at least a "fiscal union" and how could it look? Or would the kind of fiscal risk sharing that is common within nations states create even more problems and make future crises even more likely? Can a "one size fits all" monetary policy work in Europe with its heterogeneous product and labor market institutions? The seminar will discuss the larger lessons from the crisis and the principles on which these and other questions can be answered.