Morality and Economics
It's immoral to take money from those who earned it and give it to those who didn't.
It's immoral to adopt policies which impoverish your fellow citizens
Most people, I guess, would subscribe to at least one of these, and many, like myself, would find that both resonate. In a sense, though, they are the opposite sides of the same argument. Greece, Portugal, Ireland, and Spain find themselves in economic fixes that are at least partly of their own making. How much help, if any, does the rest of Europe owe them?
Both statements, by the way, grow naturally out of fundamental aspects of human morality. Moral dilemmas grow out of conflicts between various aspects of our inherited moral principles. Ditto political conflicts, and at least some aspects of economic arguments.
It's more complicated than that of course. If the European periphery implodes, there will likely be widespread damage to the rest of Europe and the rest of the World, so Germany and the rest arguably have a selfish interest in preventing that eventuality. There is also the question of whether anything can be done and if so what. I find it highly interesting that opinions on that question break sharply along ideological lines.