If Aristotle is right that virtue is a mean between extremes, how would one decide just where that middle between too much and too little of some trait is? You cannot just KNOW where that middle point is. You must experiment. Either in your own failures or witnessing those around you, you may find that middle ground. Indulgence for example. Over indulgence, you can indulge on as much food as you want to every day, but chances are that you'll become overweight and unhealthy and suffer as a result. Polar opposite of that is under indulgence. If you do not eat enough food to meed your caloric needs, you will eventually become underweight and suffer negative health effects. You have to find a happy medium which is where you find your zone of virtue. What do you think about Philippa Foot’s problem regarding whether the virtuous person is one who finds being virtuous easy or difficult? I think everyone can be virtuous in a different way. Foot brings up a good point with the bank robbery example. She mentions that if that person "does so courageously, demonstrates the virtue of courage." This is obviously an immoral action, but you most certainly need courage to rob a bank. Of course you also need courage to stand up to that very same bank robber, and if you look at them side by side, I would say that the person standing up to the bank robber is more virtuous. But they both may have the virtue of courage.