Alfred Nobel was a chemist, engineer, and inventor. In fact, he invented dynamite and held hundreds of other patents. He even got his own atomic element. How awesome is that?
He was also a weapons manufacturer. Now, as an engineer, I can honestly say that I would not mind creating or developing weapons (which I have done in the past). To me, it is just getting paid to play with interesting technology, science, and problem-solving (which is all I want to do in this life). However, I am also a lover of life, peace, and beauty. I have a real problem when the weapons actually get used to end human life (rather than simply being stockpiled or used for purely defensive measures).
This was Alfred’s position, too. When his obituary was prematurely published, it labeled him a “merchant of death”. As a result, he surrendered his fortune to be used for the Nobel Prize (including the Nobel Peace Prize; 1901) upon his death.