Ethics don't hold science back, they hold it accountable. The ends do not justify the means. Dr. Josef Mengele was a monster that we should hold in absolute contempt, not glorify. His "science" may have yielded results, but the cost was too high. That any good came from his atrocities is not proof that we should forgo our humanity for the possible advancement of science.
Stem cell research is not being held back by ethics or religion. The frozen embrios were never made illigal. In fact they were the only legal way to harvest embrionic stem cells. People don't want to destroy life even to save life. That's why we only harvest donor organs from those who's lives can't be saved. Because it's ethically wrong to create life just to destroy it, people were against embrionic stem cell harvesting. Nobody wanted to see fetus factories, and for good reason. Because of that stem cell research has switched to adult stem cells which research suggests may be better in the long run. In this case ethics' effect on science was both positive and effective.
Would you really want a cure if it meant innocent human life had to suffer or be destroyed for no other purpose but for "science"?
