In the words of Ron Paul, "I lean toward a flat tax. But I want to make it real flat, like zero." Where do you get the arrogance to think you have a right to help yourself to someone else's income? And to dictate to them how much of their income you are going to help yourself to? Diminishing marginal utility is entirely irrelevant - you don't get to decide when someone else's utility is too low and you get to take what's left. You're mis-applying an economic argument and still failing the ethical argument because you are advocating TAKING SOMEONE ELSE'S MONEY. YOU ARE NOT GOOD PEOPLE. YOU ARE THIEVES. Again, where do you get the arrogance?