[Cain sighs. It is going to be a very long class.] The purpose is to learn how to make the sword move properly without hurting yourself, not to defend yourself or fight.
Sword fighting is an art as much as it is a way to fight. Any idiot can shove the pointy end of the sword into your enemy. Learning how to make the sword an extension of your body, however, takes time and also pays off far greater.