Originally posted by Psychotron
Yeah, but isn't it the philosophy of the Sith that the apprentice must kill the master and take his place?
The Rule of Two initiated by Darth Bane states that there can only be Two Sith at any given time. One to embody the power(Master), and one to crave it(Apprentice). When the apprentice gets powerful enough, they'll try to kill the master. If they succeed, then they've passed the test and are worthy of succeeding their master while choosing a new apprentice to repeat the cycle. If the Apprentice fails, then the Master just finds a new apprentice.
So while yes, the apprentice is destined to attempt to rise up and overthrow the master. But that doesn't mean it'll be successful. They're Sith after all. They're not just gonna sit back and let themselves be killed. They'll try everything to stay the Master.