Creating a computer that "thinks" is one goal of artificial intelligence research. In 1950, the great British mathematician Alan Turing guessed that "thinking computers" would arrive by 2000. But computers capable of simulating human thought processes are no closer today than they were then, because we put science before common sense.
Put simply, we failed to notice obvious and important facts about the nature of thought that exist right before our eyes. Philosophy is intended to show us facts that are so obvious that we might miss them. Most philosophers, it seems, have been asleep on the job for a long time.
Consider four familiar situations. In one, you are thinking about a problem - say, what pension plan you should join - logically and analytically. In the second, you are thinking casually, drawing on experience rather than analysis. (My computer is stuck. The last time this happened, I fixed it by doing such and such; I'll try that again.) In the third, you are looking out a window, letting your mind wander. Finally, you are asleep and dreaming.
The single most important fact about thought follows from an obvious observation: these four styles are connected. We can label them "analysis," "common sense," "free association," and "dreaming." But the key point is that they are four points on a single continuous spectrum, with analysis at one end and dreaming at the other.