It’s not hard to understand why you need a teacher. You need to have a mirror to fix your hair or apply your lipstick properly. It’s certainly physically possible to do these things without a mirror, and there are no laws against it. But you’d have no real idea what you actually looked like until you walked outside and everyone started giggling at you because you’d smeared lipstick all over your nose. A good Buddhist teacher can be your mirror. The teacher, in turn, learns to use his or her students as a mirror in a similar way.
