Ogion is the type of teacher we all want – he doesn't talk a lot, and he lets his students wander around all afternoon. He's actually Ged's second magic teacher, but he's the first person to teach Ged all about the Balance. And that's what he's really all about.
When Ged first goes off as Ogion's apprentice, Ged expects it to be all fireballs and explosions, but Ogion won't even cast a spell to get the rain off him (2.16). Why? Because of the Balance, of course. This is a very important lesson, but it's one that Ged just won't understand. Even though Ged tells Ogion that he's Ged's true master (7.113), Ged just won't understand this whole Balance thing until he's much older. (Like, four years older and after one shadow monster attack and probably five comas.)
Now, just because Ogion is all about the Balance, that doesn't mean he never acts. In fact, Ogion not only uses magic to banish a little shadow monster, he's also used magic in the past to totally ruin an earthquake's day (2.55). To sum up, Ogion is all about the Balance, but he'll still cast a spell to save a lot of people. (Also, we imagine that when he stopped the earthquake, he did it by listening very closely to the earth and found a way to still preserve the Balance – what a dynamo.)
Also, his name means fir-cone (4.101), but we're not sure if that means anything. Then again, a cone is a seed and Ogion does help things grow. And a fir is an evergreen tree, and Ogion is pretty ever-calm. Maybe it's all the Balance.