actions . . The encoding, the conversion from one modality to the other, served a purpose. In the case of Morse code, the purpose was to turn everyday language into a form suitable for near-instantaneous transmission across miles of copper wire. In the case of symbolic logic, the new form was suitable for manipulation by a calculus. The symbols were like little cap- sules, protecting their delicate cargo from the wind and fog of everyday communication. How much safer to write: 1 - x = )(1 - z) + z(1 - y) + (1 - y)(1-z) than the real-language proposition for which, in a typical Boolean exam- ple, it stood: Unclean beasts are all which divide the hoof without chewing the cud, all which chew the cud without dividing the hoof, and all which neither divide the hoof nor chew the cud. The safety came in no small part from draining the words of meaning. Signs and symbols were not just placeholders; they were operators, like the gears and levers in a machine. Language, after all, is an instrument. It was seen distinctly now as an instrument with two separate func- tions: expression and thought. Thinking came first, or so people assumed. To Boole, logic was thought-polished and purified. He chose The Laws 165 A NERVOUS SYSTEM FOR THE EARTH