A computer shall not waste your time or require you to do more work than is strictly necessary.

The system should treat all user input as sacred.

An unlimited-length file name is a file. The content of a file is its own best name.

I am confident that we can do better than GUIs because the basic problem with them (and with the Linux and Unix interfaces) is that they ask a human being to do things that we know experimentally humans cannot do well. The question I asked myself is, given everything we know about how the human mind works, could we design a computer and computer software so that we can work with the least confusion and greatest efficiency?

Once the product's task is known, design the interface first; then implement to the interface design.

A well-designed and humane interface does not have to be split into beginner and expert subsystems.

I hate mice. The mouse involves you in arm motions that slow you down. I didn't want it on the Macintosh, but Jobs insisted. In those days, what he said went, good idea or not.