東大英語　no.3

ln our daily lives we all predict and explain other people's behavior from what we think they know and what we think they want, Beliefs and desires are the explanatory tools of our own intuitive psychology, and intuitive psychology is still the most useful and complete science of behavior there is. To predict the vast majority of human acts - going to the refrigerator, getting on the bus, reaching into one's wallet -- you don't need to crank through a mathematical model, run a computer simulation of a neural network, or hire a professional psychologist; you can just ask your grandmother.
It's not that common sense should have any more authority in psychology than it does in physics or astronomy. But this part of common sense has so much power and precision in predicting, controlling, and explaining everyday behavior, compared to any alternative ever entertained, that the chances are high that it will be included in some form in our best scientific theories. I call an old friend on the other coast and we agree to meet in Chicago at the entrance of a bar in a certain hotel on a particular day two months hence at 7:45 P.M. I predict, he predicts, and everyone who knows us predicts that on that day at that time we will meet up. And we do meet up. That is amazing! In what other domain could nonexperts -- or scientists, for that matter --forecast, months in advance, the course of two objects thousands of miles apart to an accuracy of inches and minutes? And do it from information that can be conveyed in a few seconds of conversation? The calculus behind this forecasting is intuitive psychology: the knowledge that I want to meet my friend and vice versa, and that
each of us believes the other will be at a certain place at a certain time and knows a sequence of rides, hikes, and flights that will take us there. No science of mind or brain is ever likely to
do better. That does not mean that the intuitive psychology of beliefs and desires is itself a science, but it suggests that scientific psychology will have to explain how a hunk of matter, such as a human being, can have beliefs and desires and how the beliefs and desires work so well.