Why might the mean be difficult to attain?

A person achieves virtue by maintaining a balance between the extremes. The scales are never perfectly balanced, thus, a person should constantly adjust his path toward the balance point, but if he goes to one side or the other in the process, he is not to be blamed. This definition of virtue is practical in that it provides a goal for action and does not attempt to proscribe one course of action to all. Indeed, Aristotle claims that this mean is not in the same place for all people. Some might be more naturally afraid than others, and so must steer more toward bravery. Those who are naturally brave must avoid becoming rash by steering away from that extreme. The mean is determined by each individual using prudence, which is guided by reason and understanding.