I'm not sure I can provide a good answer to this question. As a mechanical engineer, my jobs were to ensure that mechanical equipment was designed, built, and maintained as well as it could be. Whether the equipment was used for "good" or "bad" was out of my control. I remember one time walking by an aircraft carrier in drydock and thinking that it took billions of dollars to design, build, maintain, and operate; and its main purpose was to be one of the most deadly killing machines in human history. I also remember thinking how grateful I was that we (America) had these machines, and that our main use of them was for good.