Ribbon in the Sky by Murray Leinster — Read

"An error is a denial of reality, but mistakes are mere mental / malfunctionings. In an emergency, a mistake may be made because of / the need for precipitate action. There is no time to choose the best / course: something must be done at once. Most mistakes, however, / are made without any such exterior pressure. One accepts the / first-imagined solution to a problem without examining it, either / out of an urgent desire to avoid the labor of thinking, or out of / impassioned reluctance to think about the matter at hand when / prettier and more pleasurable other things can be contemplated. " / _The Practice of Thinking_ Fitzgerald

It turned out afterward that somebody had punched the wrong button in / a computer. It was in a matter in which mistakes are not permissible, / but just as nothing can be manufactured without an ordinary hammer / figuring somewhere in the making or the making-ready-to-make, so / nothing can be done without a fallible human operating at some stage of / the proceedings. And humans make mistakes casually, off-handedly, with / impartial lack of malice, and unpredictability. So.