There's a good deal in common between the mind's eye and the TV screen, and though the TV set has all too often been the boobtube, it could be, it can be, the box of dreams.
Ursula K. Le GuinBut you must not change one thing, one pebble, one grain of sand, until you know what good and evil will follow on that act. The world is in balance, in Equilibrium. A wizard's power of Changing and Summoning can shake the balance of the world. It is dangerous, that power...It must follow knowledge, and serve need.
Ursula K. Le Guin