It can be surprisingly easy to simulate intelligence in a computer. In the 1960s Joseph Weizenbaum developed the famous ELIZA program, a conversational system that uses simple language rules to simulate a Rogerian psychotherapist (Weizenbaum 1976). Itresponds in particular ways to mentions of keywords or phrases (e.g., "mother," "I think"), rephrases stated concerns in a questioning fashion designed to draw people out, makes mild remarks about assertions, and so on. Weizenbaum made no claims of intelligence in ELIZA, but interactions with its simple teletype interface were sometimes quite convincing. Appearing below is an excerpt from a continuing dialog between ELIZA and a patient (available at www.word.com/newstaff/tclark/three/index.html):

E:	HELLO. MY NAME IS ELIZA. WHAT'S YOURS?
T:	Tomas.
E:	ALRIGHT, TOMAS, WHAT WOULD YOU LIKE TO TALK ABOUT TODAY?
T:	I am sorry I got angry at you earlier, Eliza.
E:	DO YOU ENJOY BEING SORRY YOU GOT ANGRY AT I EARLIER?
T:	Enjoy it? No, I am feeling guilty.
E:	I WOULD CONCUR, YOU ARE FEELING GUILTY.
T:	Thank you for that confirmation.
E:	PLEASE DON'T MENTION IT.
T:	All right. I am feeling less angry now.
E:	OH, YOU ARE?
T:	I think so. Maybe it has just bubbled beneath the surface again.
E:	YOU SEEM TO BE A RATHER PENSIVE INDIVIDUAL.
T:	When I am talking to you, I try to examine myself.
E:	LET'S MOVE ON NOW, IF YOU PLEASE.

Once you know how ELIZA works, it's easy to trick it into saying silly things, or using...