Let's forget about skepticism, and assume the physical world exists, including your bodyand your brain; and let's put aside our skepticism about other minds. I'll assume you'reconscious if you assume I am. Now what might be the relation between consciousnessand the brain?Everybody knows that what happens in consciousness depends on what happens to thebody. If you stub your toe it hurts. If you close your eyes you can't see what's in front ofyou. If you bite into a Hershey bar you taste chocolate. If someone conks you on the headyou pass out.The evidence shows that for anything to happen in your mind or consciousness,something has to happen in your brain. (You wouldn't feel any pain from stubbing yourtoe if the nerves in your leg and spine didn't carry impulses from-27-the toe to your brain.) We don't know what happens in the brain when you think, "Iwonder whether I have time to get a haircut this afternoon." But we're pretty suresomething does -something involving chemical and electrical changes in the billions ofnerve cells that your brain is made of.In some cases, we know how the brain affects the mind and how the mind affects thebrain. We know, for instance, that the stimulation of certain brain cells near the back ofthe head produces visual experiences. And we know that when you decide to helpyourself to another piece of cake, certain other brain cells send out impulses to themuscles in your arm. We don't know many of the details, but it is clear that there arecomplex relations between what happens in your mind and the physical processes that goon in your brain. So far, all of this belongs to science, not philosophy.But there is also a philosophical question about the relation between mind and brain, andit is this: Is your mind something different from your brain, though connected to it, or is ityour brain? Are your thoughts, feelings, perceptions, sensations, and wishes things thathappen in addition to all the physical processes in your brain, or are they themselvessome of those physical processes? -28-What happens, for instance, when you bite into a chocolate bar? The chocolate melts onyour tongue and causes chemical changes in your taste buds; the taste buds send someelectrical impulses along the nerves leading from your tongue to your brain, and whenthose impulses reach the brain they produce further physical changes there; finally, youtaste the taste of chocolate. What is that? Could it just be a physical event in some ofyour brain cells, or does it have to be something of a completely different kind?If a scientist took off the top of your skull and looked into your brain while you wereeating the chocolate bar, all he would see is a grey mass of neurons. If he usedinstruments to measure what was happening inside, he would detect complicated physicalprocesses of many different kinds. But would he find the taste of chocolate?It seems as if he couldn't find it in your brain, because your experience of tastingchocolate is locked inside your mind in a way that makes it unobservable by anyone else-- even if he opens up your skull and looks inside your brain. Your experiences are insideyour mind with a kind of insideness that is different from the way that your brain is insideyour head. Someone else can open up your head and see what's inside, but-29-they can't cut open your mind and look into it -at least not in the same way.It's not just that the taste of chocolate is a flavor and therefore can't be seen. Suppose ascientist were crazy enough to try to observe your experience of tasting chocolate bylicking your brain while you ate a chocolate bar. First of all, your brain probably wouldn'ttaste like chocolate to him at all. But even if it did, he wouldn't have succeeded in gettinginto your mind and observing your experience of tasting chocolate. He would just havediscovered, oddly enough, that when you taste chocolate, your brain changes so that ittastes like chocolate to other people. He would have his taste of chocolate and you wouldhave yours.If what happens in your experience is inside your mind in a way in which what happensin your brain is not, it looks as though your experiences and other mental states can't justbe physical states of your brain. There has to be more to you than your body with itshumming nervous system.One possible conclusion is that there has to be a soul, attached to your body in some waywhich allows them to interact. If that's true, then you are made up of two very differentthings: a complex physical organism, and a soul which is purely mental. (This view iscalled dualism, for obvious reasons.)