I want them to have heard me affirm that the computer is a powerful new metaphor for helping us to understand many aspects of the world but that it enslaves the mind that has no other metaphors and few resources to call on. The world is many things, and no single framework is large enough to contain them all, neither that of man's science nor that of his poetry, neither that of calculating reason nor that of pure intuition. And just as love of music does not suffice to enable one to play the violin-- one must also master the craft of the instrument and of music itself--so is it not enough to love humanity in order to help it survive. The teacher's calling to teach his craft is therefore an honorable one. But he must do more than that: he must teach more than one metaphor, and he must teach more by the example of his conduct than by what he writes on the blackboard. He must teach the limitations of his tools as well as their power. -- Joseph Weizenbaum, Computer Power and Human Reason, p.277, W.H.Freeman and Co. 1974