Many people insist on having some definition of intelligence.
CRITIC: How can we be sure that things like plants and stones, or storms and streams, are not intelligent in ways that we have not yet conceived?
It doesn't seem a good idea to use the same word for different things, unless one has in mind important ways in which they are the same. Plants and streams don't seem very good at solving the kinds of problems we regard as needing intelligence.
CRITIC: What's so special about solving problems? And why don't you define intelligence precisely, so that we can agree on what we're discussing?
That isn't a good idea, either. An author's job is using words the ways other people do, not telling others how to use them. In the few places the word intelligence appears in this book, it merely means what people usually mean — the ability to solve hard problems.
CRITIC: Then you should define what you mean by a hard problem. We know it took a lot of human intelligence to build the pyramids — yet little coral reef animals build impressive structures on even larger scales. So don't you have to consider them intelligent? Isn't it hard to build gigantic coral reefs?
Yes, but it is only an illusion that animals can solve those problems! No individual bird discovers a way to fly. Instead, each bird exploits a solution that evolved from countless reptile years of evolution. Similarly, although a person might find it very hard to design an oriole's nest or a beaver's dam, no oriole or beaver ever figures out such things at all. Those animals don't solve such problems themselves; they only exploit procedures available within their complicated gene-built brains.
CRITIC: Then wouldn't you be forced to say that evolution itself must be intelligent, since it solved those problems of flying and building reefs and nests?
No, because people also use the word intelligence to emphasize swiftness and efficiency. Evolution's time rate is so slow that we don't see it as intelligent, even though it finally produces wonderful things we ourselves cannot yet make. Anyway, it isn't wise to treat an old, vague word like intelligence as though it must define any definite thing. Instead of trying to say what such a word means, it is better simply to try to explain how we use it.
Our minds contain processes that enable us to solve problems we consider difficult. Intelligence is our name for whichever of those processes we don't yet understand.
Some people dislike this definition because its meaning is doomed to keep changing as we learn more about psychology. But in my view that's exactly how it ought to be, because the very concept of intelligence is like a stage magician's trick. Like the concept of the unexplored regions of Africa, it disappears as soon as we discover it.