The teacher who is indeed wise does not bid you to enter the house of his wisdom but rather leads you to the threshold of your mind.

Kahlil Gibran

A person who has a cat by the tail knows a whole lot more about cats than someone who has just read about them.

Mark Twain

To know how to suggest is the art of teaching.

Henri-Frederic Amiel

I touch the future; I teach.

Christa McAuliffe

A good teacher is one whose students surpass him and make him increasingly less necessary

Author Unknown

School can be a tool of torture or an instrument of inspiration.

David Higgins (original author - Goethe: see below, David Higgins adapted the phrase in term of schooling)