I'm a fan of his closing statement, though this sticks in particular:

"...there is room for indisputable certainty, that is, initial choices that make unexpected events harmless."

I also code by the ideal that you should have a fine line between expected and unexpected behavior, and generally avoid tacking on special cases as your needs grow. Of course, various realistic constraints make can make this difficult, but that's why it's an "ideal". :-D