In real life, you often have to deal with things you don't completely understand. You drive a car, not knowing how its engine works. You ride as passenger in someone else's car, not knowing how that driver works. Most strange of all, you drive your body and your mind, not knowing how your own self works. Isn't it amazing that we can think, not knowing what it means to think? Isn't it remarkable that we can get ideas, yet not explain what ideas are?
In every normal person's mind there seem to be some processes that we call consciousness. We usually regard them as enabling us to know what's happening inside our minds. But this reputation of self-awareness is not so well deserved, because our conscious thoughts reveal to us so little of what gives rise to them.
Consider how a driver guides the immense momentum of a motorcar, not knowing how its engine works or how its steering wheel directs it to the left or right. Yet when one comes to think of it, we drive our bodies in much the same way. So far as conscious thought is concerned, you turn yourself to walk in a certain direction in much the way you steer a car; you are aware only of some general intention, and all the rest takes care of itself. To change your direction of motion is actually quite complicated. If you simply took a larger or smaller step on one side, the way you would turn a rowboat, you would fall toward the outside of the turn. Instead, you start to turn by making yourself fall toward the inside — and then use centrifugal force to right yourself on the next step. This incredible process involves a huge society of muscles, bones, and joints, all controlled by hundreds of interacting programs that even specialists don't yet understand. Yet all you think is, Turn that way,
and your wish is automatically fulfilled.
We give the name signals to acts whose consequences are not inherent in their own character but have merely been assigned to them. When you accelerate your car by pressing on the gas pedal, this is not what does the work; it is merely a signal to make the engine push the car. Similarly, rotating the steering wheel is merely a signal that makes the steering mechanism turn the car. The car's designer could easily have assigned the pedal to steer the car or made the steering wheel control its speed. But practical designers try to exploit the use of signals that already have acquired some significance.
Our conscious thoughts use signal-signs to steer the engines in our minds, controlling countless processes of which we're never much aware. Not understanding how it's done, we learn to gain our ends by sending signals to those great machines, much as the sorcerers of older times used rituals to cast their spells.