HAL's emotions are no longer surprising, given what we know now about the important role emotions play in rational and creative decision making, in natural friendly communication, and even in art appreciation. No longer should we think of emotion as a luxury added to HAL's character just for emotional appeal. Instead, we can see HAL as the prototype of a truly affective computer -- one whose abilities to recognize and express emotions are essential for communicating as well as for user-friendly responses. The ability to experience emotions, or at least states that seem to parallel human emotional states, appears to be critical to flexible and intelligent computer decision making. There is, however, danger in all of this, a danger that machines will have emotions, but not sufficient intelligence to use them properly. Nonetheless, the problem of HAL's life-threatening behavior in 2001 is probably not as imminent as our need for emotional intelligence in machines.

Do we, then, want to build an intelligent, friendly, flexible machine like HAL? Yes. Are emotions necessary to such a machine? Apparently, yes. In fact, lack of emotions may be a key reason why artificial intelligence has failed at this task to date. But there is another question -- and I don't know the answer: are people ready for affective computers?