In the long term, however, it is up to the lawmakers and society to determine whether they will accept or reject what the scientists tell them. If society decides the genetic engineering that flows from Watson and Crick's discoveries is an unacceptable tinkering with life, then it can rule it out of bounds. By the same token, if it is unhappy about a new laser that could be used to blind enemy troops, then it can decide to block funding for it and accept international conventions that make the use of these devices a crime against humanity.
Scientists would generally prefer clearly defined strictures. They would welcome the creation of guidelines that would allow them to pursue their creative efforts without having to censor their own work or work surreptitiously on projects that in time may be ruled out as unethical. The purpose of science is to discover new knowledge, to better understand the world in which we live. It doesn't matter whether this voyage of discovery is directed towards cosmology and the formation of the universe, or to the biochemistry associated with life-giving processes.
Nor will such controls take away the ability of science to bring about change and evolution within society. If a radical, cheap, non-polluting form of energy were discovered tomorrow, it would mean a profound change in the way we consume energy. It might alter transportation modes or house design and would certainly change the way we are affecting our environment. Such discoveries are certainly rare but, given a vigorous scientific community, are always just around the next corner.