If you find yourself thinking that if you don’t do it, someone else will…immediately stop doing it.
That’s right – don’t think about it. Don’t second guess yourself: if the reason you are thinking about doing something is primarily because if you don’t do that thing, someone else will, reject the idea and the plan without further examination. Distract yourself with other thoughts and move on without regret. The reason I say this is because, inevitably, if you are using the above rationale to justify your actions, you have misgivings—on moral grounds—about the correctness of those actions…or the actions aren’t something you would typically engage in (probably for very good reasons). Sure, there are circumstances where the above assumptions may not be applicable, but I’ll bet that they almost always will be. Your clue to a troubled conscience is the presence of the mode of thinking that this aphorism describes.