Some regard more the rigor of the game than the winning of it, but to the world the discredit of the final failure does away with any recognition of the previous care. The victor need not explain. The world does not notice the details of the measures employed; but only the good or ill result. You lose nothing if you gain your end. A good end gilds everything, however unsatisfactory the means. Thus at times it is part of the art of life to transgress the rules of the art, if you cannot end well otherwise.
Play both sides against the middle and the middle against itself.
When you have a lower-level job, being exceptionally good at it is usually a deterrent to getting promoted. For example, when you’re such a great assistant that your boss has difficulty functioning without you, it means that he or she will keep you on as an assistant as long as possible and will not consider promoting you out of their service.