Thinking Means Understanding in More Than One Way

Thus, your knowledge is represented in various forms that are stored in different regions of the brain, to be used by different processes. What are those representations like? In the brain, we do not yet know. However, in the field of Artificial Intelligence, researchers have found several useful ways to represent knowledge, each better suited to some purposes than to others. The most popular ones use collections of "If-Then" rules. Other systems use structures called 'frames'--which resemble forms that are filled out. Yet other programs use web- like networks, or schemes that resemble tree-like scripts. Some systems store knowledge in language- like sentences, or in expressions of mathematical logic. A programmer starts any new job by trying to decide which representation will best accomplish the task at hand. Typically then, a computer program uses only a single representation and if this should fail, the system breaks down. This shortcoming justifies the common complaint that computers don't really "understand" what they're doing.

But what does it mean to understand? Many philosophers have declared that understanding (or meaning, or consciousness) must be a basic, elemental ability that only a living mind can possess. To me, this claim appears to be a symptom of "physics envy"--that is, they are jealous of how well physical science has explained so much in terms of so few principles. Physicists have done very well by rejecting all explanations that seem too complicated, and searching, instead, for simple ones. However, this method does not work when we're dealing with the full complexity of the brain. Here is an abridgment of what I said about understanding in my book, The Society of Mind. "If you understand something in only one way, then you don't really understand it at all. This is because, if something goes wrong, you get stuck with a thought that just sits in your mind with nowhere to go. The secret of what anything means to us depends on how we've connected it to all the other things we know. This is why, when someone learns 'by rote,' we say that they don't really understand. However, if you have several different representations then, when one approach fails you can try another. Of course, making too many indiscriminate connections will turn a mind to mush. But well-connected representations let you turn ideas around in your mind, to envision things from many perspectives until you find one that works for you. And that's what we mean by thinking!"