What we need is a plan B ... independent of the Internet. [It] doesn't necessarily have to have the performance of the Internet, but the police department has to be able to call up the fire department.

An attitude of only taking what you need was built into the protocols of the Internet itself.

The computers are in control. We just live in their world.

People are mostly focused on defending the computers on the Internet, and there's been surprisingly little attention to defending the Internet itself as a communications medium. And I think we probably do need to pay some more attention to that, because it's actually kind of fragile.

Last century, when the beams needed replacing, carpenters used oak trees that had been planted in 1386 when the dining hall was first built. The 14th-century builder had planted the trees in anticipation of the time, hundreds of years in the future, when the beams would need replacing. Did the carpenters plant new trees to replace the beams again a few hundred years from now?

[Language is] really a pretty amazing invention if you think about it. Here I have a very complicated, messy, confused idea in my head. I'm sitting here making grunting sounds and hopefully constructing a similar messy, confused idea in your head that bears some analogy to it.

A novice was trying to fix a broken Lisp machine by turning the power off and on. Knight, seeing what the student was doing, spoke sternly: "You cannot fix a machine by just power-cycling it with no understanding of what is going wrong." Knight turned the machine off and on. The machine worked.