While a program expresses intent, it is the computer, the hardware, that brings that intent to life. In order to have full control over your program's expression you must control the computer that runs it. Therefore, write your program for a computer with a plug. Should you be dissatisfied with the behavior of the computer, unplug it.

I'm working from memory here. This idea, the idea that you could unplug a computer, is an idea that has run in and out of our culture for about as long as there have been computers. I've expressed the idea as a pattern: a problem and its solution. I'm thinking about this pattern because it reminds me of programming with Kent.

I haven't got the words to this pattern quite right. It gives the impression that I fear computers run amuck. Does anybody remember that old film, The Forbin Project, where the U.S. defense computer gets to talking to the Soviet defense computer and they get the idea that they can run the world better than us? Well, that's not the problem. I first wrote the “don't program a computer you can't unplug” pattern because Kent and I needed a pattern at a large scale. We were looking for big advice for a new kind of developer. We imagined ordinary people taking their computing needs into their own hands. These people would use powerful languages to express themselves.