Constants are widely known for the detestable practice of changing their values; we should prepare ourselves against the consequences of such fickleness
Bertrand MeyerCorrectness is clearly the prime quality. If a system does not do what it is supposed to do, then everything else about it matters little.
Bertrand MeyerWriting 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.
Bertrand MeyerCareful as they may be, developers of Eiffel libraries will always run into cases in which, after releasing a library class, they suddenly experience what in French is called esprit de l'escalier or wit of the staircase: a great thought which unfortunately is an afterthought, like a clever reply that would have stunned all the other dinner guests - if only you had thought of it before walking down the stairs after the party is over.
Bertrand Meyer