Software entities (classes, modules, functions, etc.) should be open for extension, but closed for modification.

Constants are widely known for the detestable practice of changing their values; we should prepare ourselves against the consequences of such fickleness

Incorrect documentation is often worse than no documentation.

As Mr. Nagle so competently points out, almost no one uses Eiffel; in fact until recently there were only 9 users. But now a 10th person just started, so we are holding a conference, appropriately titled the TENTH Eiffel USER conference, to celebrate.

Eiffel borrows quite openly from several earlier programming languages and I am sure that if we had found a good language construct in C we would have used it as well.

I have always felt sympathy towards the biologists who accept to debate creationists. Now I also understand them better; one can fight opinions, not articles of faith.

Writing a class without its contract would be similar to producing an engineering component (electrical circuit, VLSI (Very Large Scale Integration) chip, bridge, engine...) without a spec. No professional engineer would even consider the idea.