From On Intelligence:
Let me show why computing is not intelligence. Consider the task of catching a ball. Someone throws a ball to you, you see it traveling towards you, and in less than a second you snatch it out of the air. This doesn't seem too difficult-until you try to program a robot arm to do the same. As many a graduate student has found out the hard way, it seems nearly impossible. When engineers or computer scientists try to solve this problem, they first try to calculate the flight of the ball to determine where it will be when it reaches the arm. This calculation requires solving a set of equations of the type you learn in high school physics. Next, all the joints of a robotic arm have to be adjusted in concert to move the hand into the proper position. This whole operation has to be repeated multiple times, for as the ball approaches, the robot gets better information about its location and trajectory. If the robot waits to start moving until it knows exactly where the ball will land it will be too late to catch it. A computer requires millions of steps to solve the numerous mathematical equations to catch the ball. And although it's imaginable that a computer might be programmed to successfully solve this problem, the brain solves it in a different, faster, more intelligent way.