"Human life is the basis of all goods, and is the necessary source and condition of every human activity and of all society."* In other words, to deprive you of life is to deprive you of all rights and of all possibilities on earth. Therefore, we as a society have held that the taking of a human life is serious, momentous, and radical. We offer extensive appeals on the death penalty to ensure that an innocent human life is not taken. We punish murder and manslaughter. We do not enter into war quickly or willingly, and observe rules of warfare. Our accepted social norms recognize the unique importance of a human life, and the seriousness of taking it.

Were we consistent, we would not be having the current debate on embryonic stem-cell research. Is an embryo an innocent human life? If you answer "yes", then you must oppose killing the embryo in order to extract stem cells. If you answer "no", then I challenge you to prove your position. Prove, beyond any reasonable doubt, that an embryo is not an innocent human life.

You see, the burden of proof is on the one who would take an innocent human life, who would kill. We would bring charges against someone who threw a grenade into a room, killing those within. If that person argued that he was unaware that anyone was in the room, he still would be charged with manslaughter. If you are going to demolish a building by explosion, the burden is on you to make sure that no one is in the building before you detonate the explosives. Society expects that you will search the building, fence the building, and search again immediately before detonation. Society expects that we will take active steps so as not to kill.

Since human life is the basis of all other goods so that the taking of a human life is momentously radical, those who would "harvest" human embryos must prove they are not killing innocent human life.

* Quoted from the Declaration on Euthanasia by the Congregation for the Doctrine of the Faith.