Aristotle's first run for being good is that there are no rules. Being good is about developing your character, so that you are disposed to do the best thing in each situation. It is NOT about internalizing some moral manual. Human being are creatures of habit and just as a good musician becomes so by practicing, so, by doing virtuous things, we become virtuous people.
But then the question becomes, "What is virtue?" According to Aristotle it is living according to our natures as rational animals. A good dog does doggy things well. A good human does good human things. We can be guided towards the right action by NOT thinking of good and bad as opposite ends of a spectrum but we must think of good as lying on a "mean" or middle of the two BAD extremes. For instance, courage lied between the excess of rashness and the deficiency of cowardice; generosity between meanness and profligacy; kindness between the excess of ignoring others and the deficiency of indulgence.
Aristotle's ethics are about more than being good - they are about living right. So doing the right thing is not about following rules, but striking the correct balance according to the circumstances.
This seems to make sense and in a society where people actually have the urge to BE virtuous or good, it would work. Unfortunately we live in a society where people no longer believe in virtue or goodness. So we lock up our kids after school instead of letting them play in the streets, we take the keys out of our cars in our driveways and lock our houses at night.
The thinking is circular and so illogical. We know what the right thing to do is because we see it in the good people, we know they are good people because they do good things, they do good things because ... they are good people. Um, wait?
Now Aristotle was attempting to describe a perfect world but as long as selfishness, greed, and evil is present there will not be a perfect world. But that doesn't mean you should not be virtuous or good. What it means is that you must work VERY HARD at being good in a bad world. It also means that we need some OUTSIDE standard that will determine whether what we do is good or not because we cannot rely on the good we see in others.
Now, where did we put that 10 commandments again? Oh, yea, here it is!