Any inaccuracies in this index may be explained by the fact that it has been prepared with the help of a computer.

Science is what we understand well enough to explain to a computer. Art is everything else we do.

The important thing, once you have enough to eat and a nice house, is what you can do for others, what you can contribute to the enterprise as a whole.

Meta-design is much more difficult than design; it's easier to draw something than to explain how to draw it.

Programs are meant to be read by humans and only incidentally for computers to execute.

When you write a program, think of it primarily as a work of literature. You're trying to write something that human beings are going to read. Don't think of it primarily as something a computer is going to follow. The more effective you are at making your program readable, the more effective it's going to be: You'll understand it today, you'll understand it next week, and your successors who are going to maintain and modify it will understand it.

...One of the most important lessons, perhaps, is the fact that SOFTWARE IS HARD. From now on I shall have significantly greater respect for every successful software tool that I encounter. During the past decade I was surprised to learn that the writing of programs for TeX and Metafont proved to be much more difficult than all the other things I had done (like proving theorems or writing books). The creation of good software demand a significiantly higher standard of accuracy than those other things do, and it requires a longer attention span than other intellectual tasks.