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

Hotheads | 373apartment, I can force open a window, call the landlord, or try to reachthe latch through the mail slot. Each of these goals is attained by a chainof subgoals. My fingers won't reach the latch, so the subgoal is to findpliers. But my pliers are inside, so I set up a sub-subgoal of finding astore and buying new pliers. And so on. Most artificial intelligence systemsare built around means and ends, like the production system inChapter 2 with its stack of goal symbols displayed on a bulletin boardand the software demons that respond to them.But where does the topmost goal, the one that the rest of the programtries to attain, come from? For artificial intelligence systems, it comesfrom the programmer. The programmer designs it to diagnose soybeandiseases or predict the next day's Dow Jones Industrial Average. Fororganisms, it comes from natural selection. The brain strives to put itsowner in circumstances like those that caused its ancestors to reproduce.(The brain's goal is not reproduction itself; animals don't know thefacts of life, and people who do know them are happy to subvert them,such as when they use contraception.) The goals installed in Homo sapiens,that problem-solving, social species, are not just the Four Fs. Highon the list are understanding the environment and securing the cooperationof others.And here is the key to why we have emotions. An animal cannot pursueall its goals at once. If an animal is both hungry and thirsty, it shouldnot stand halfway between a berry bush and a lake, as in the fable aboutthe indecisive ass who starved between two haystacks. Nor should it nibblea berry, walk over and take a sip from the lake, walk back to nibbleanother berry, and so on. The animal must commit its body to one goal ata time, and the goals have to be matched with the best moments for achievingthem. Ecclesiastes says that to every tiling there is a season, and a timeto every purpose under heaven: a time to weep, and a time to laugh; atime to love, and a time to hate. Different goals are appropriate when a lionhas you in its sights, when your child shows up in tears, or when a rival callsyou an idiot in public.The emotions are mechanisms that set the brain's highest-level goals.Once triggered by a propitious moment, an emotion triggers the cascadeof subgoals and sub-subgoals that we call thinking and acting. Becausethe goals and means are woven into a multiply nested control structureof subgoals within subgoals within subgoals, no sharp line divides thinkingfrom feeling, nor does thinking inevitably precede feeling or viceversa (notwithstanding the century of debate within psychology over