Suppose, if you will, that alien scientists came down to Earth and began to study the local lifeforms. But let’s suppose that these aliens arrive by the side of a busy expressway, and stay there. Our extraterrestrials might conclude that cars are the dominant inhabitants of Earth.

Cars clearly exhibit intelligent behaviour, being able to navigate around obstacles and follow complex instructions on road signs. How, the aliens may wonder, do the cars manage this? What is the seat of car int