{ 1 } - we should feel free to do whatever we want to do.
{ 2 } - we ought to take the safer course -- and not do what genuinely might be seriously wrong.

Suppose that we have a revolver in our hand with some live bullets, but we don't know how many. If we point the gun to someone's head and pull the trigger, it might go off or it might not. It would be wrong to pull the trigger if there's a genuine possibility that it might go off. Similarly, it would be wrong to have an abortion if there's a genuine possibility that it might be as evil to do this as to kill a five-year-old child.