Steven Pinker -- How the Mind Works - Hampshire High Italian ...

Thinking Machines 71triggered to do something, exactly as a gumball machine responds to theshape and weight of a coin by releasing a gumball.The example to come is an attempt to demystify computation, to getyou to see how the trick is done. To hammer home my explanation of thetrick—that symbols both stand for some concept and mechanicallycause things to happen—I will step through the activity of our productionsystem and describe everything twice: conceptually, in terms of thecontent of the problem and the logic that solves it, and mechanically, interms of the brute sensing and marking motions of the system. The systemis intelligent because the two correspond exactly, idea-for-mark, logical-step-for-motion.Let's call the portion of the system's memory that holds inscriptionsabout family relationships the Long-Term Memory. Let's identify anotherpart as the Short-Term Memory, a scratchpad for the calculations. A part ofthe Short-Term Memory is an area for goals; it contains a list of questionsthat the system will "try" to answer. The system wants to know whetherGordie is its biological uncle. To begin with, the memory looks like this:Lono-Term Memory Short-Term Memory GoalAbel parent-of MeAbel is-maleBella parent-of MeBella is-femaleClaudia sibling-of MeClaudia is-femaleDuddie sibling-of MeDuddie is-maleEdgar sibling-of AbelEdgar is-maleFanny sibling-of AbelFanny is-femaleGordie sibling-of BellaGordie is-maleGordie uncle-of Me?Conceptually speaking, our goal is to find the answer to a question; theanswer is affirmative if the fact it asks about is true. Mechanically speaking,the system must determine whether a string of marks in the Goal columnfollowed by a question mark (?) has a counterpart with an identicalstring of marks somewhere in memory. One of the demons is designed to