It is possible that a scientific discovery will be made that humans will later regret because it has awful consequences. The problem is, we probably would not know in advance and, once the discovery is made, it cannot be undiscovered.
“The fears of one class of men are not the measure of the rights of another.”
“How do you explain the bond between man and wife? Well, for one thing, it's private. What people do in their own marriage is their own business.”