Let me say a little about today’s computer. This is a brain, though not an exciting intellectual generalist. The cortex has a thousand times as many nerve cells, but those of the computer are ten thousand times more speedy and reliable. The nerve cells here, as in the cortex, transact their affairs by electric impulses, which may be interpreted as symbols in the most general way. Those of the computer are in fact interpreted, usually, as numbers, or as instructions pertinent to arithmetic, the task it is deliberately organized to do. It can do as much arithmetic in a minute as a man in a lifetime. Moreover, a man would make millions of errors during this lifetime, whereas if the machine made one after so little work, we would cut off the rent.