In order to understand mind reading as I am about to describe it, it is important that you first understand a different concept. The phi-losopher, mathematician, and scientist René Descartes was one of the great intellectual giants of the seventeenth century. The effects of the revolution he instigated within mathematics and Western philosophy are still being felt today. Descartes died in 1650 of pneumonia in the Royal Palace in Stockholm, where he was tutoring Queen Christina. Descartes was used to working in his warm, cozy bed, as befits a French philosopher, so the cold stone floors of the castle quite understandably finished him off once winter set in. Descartes did a great deal of good, but he also made some serious mistakes. Before he died, he introduced the notion that body and mind were separate.
This was pretty much the most stupid thing he could have come up with, but Descartes had won the car of the intelligentsia, thanks to neat sound bites like Cogito, ergo sum (I think, therefore 1 am). As a result of his popularity, the peculiar (and basically religious) notion that human beings are made of two different substances—a body and a soul—-gained ground.
There were naturally those who thought he was wrong, but their voices were drowned out by the cheers of celebration for Descartes's idea. Only in recent times have biologists and psychologists been able to scientifically prove the exact opposite of Descartes's claim; perhaps the most notable among them is the world-famous neurologist Antonio Damasio. Now we know that the body and mind are actually inextricably linked, in both the biological and the mental senses. But Descartes's view was dominant for so long that it is still taken as an accepted truth by most people.
Most of us still differentiate, albeit unconsciously, between our bodies and our thought processes. If the rest of this book is going to make any sense to you, it is important to understand that this isn't the case, even if it feels a bit strange to think this way at first.
Here's how it is: you can't think a single thought without something physical happening to you as well. When you think a thought, an electrochemical process occurs in your brain. In order for you to create a thought, certain brain cells have to send messages to each other according to certain patterns. If you have had a thought before, the pattern for it is already established. All you're doing then is repeating the pattern. If it is an entirely new thought, you create a new pattern or network of cells in your brain. This pattern also influences the body and can change the dissemination of hormones (such as endorphins) throughout your body, as well as in the autonomous nervous system. The autonomous nervous system governs things like breathing, the size of our pupils, blood flow, sweating, blushing, and so on.
Every thought affects your body in some way or other, sometimes in a very obvious way. If you're frightened, your mouth will go dry and the blood flow to your thighs will increase in preparation for possibly running away. If you start to have sexual thoughts about the guy at the supermarket checkout, you'll notice other, very obvious reactions in your body—even if it is only a thought. Sometimes the reactions are so small that they're invisible to the naked eye. But they are always there. This means that by simply being observant of the physical changes that occur in a person, we can get a good idea of how she is feeling, what her emotions are, and what she is thinking. By training yourself at observation, you will also learn to see things that were previously too subtle for you to notice.