When its global warming we have to act now without evidence-just in case. When its abortion, we have to assume their is no pain got the fetus unless we have unimpeachable evidence.
Is it really OK to assassinate somebody if, when you made the hit, they were unconcious, anesthetized, or asleep?
A Harvard Med School grad doctor once told me, "I don't know exactly when human life 'began.' If could have been one million years ago. But I do know that human life is TRANSMITTED to a new generation, every time a fertilization occurs."