That involves a lot more than just that simple question. I firmly believe that without science we would not be where we are today & I'm not talking about the destructive stuff but rather the mundane - starting a fire, cracking rocks to make sharp edges so you can skin animals for clothing, farming, building shelters etc. All of these may not seem like science but at some stage someone researched each of these to find the right materials, experimentation - the very basis of science.
Now move forward to today, Stem Cell Research, is a big thing with a lot of people opposed to it but if it could give sight back to the blind or a repair a broken spine. My heart & lungs don't work & I guess I'm hoping that stem cell research can get there before I die. A lot of people want to stop this sort of research, as they do with The Great Hadron Collider, Cloning, Nuclear Power.
I don't have an answer but one thing is clear if we had prevented someone from designing & building a spear to hunt we may not be here today. The fact that the spear was also used in war, to kill enemies is a little scary but how can we decide which inventions go on to become killing machines.
Think about this, a Dictator could use Penicillin to kill all those people that are allergic to it, if he/she so desired - does this make Penicillin a bad thing?