Brief summary of arguments against cloning

I am not a bioethicist, nor do I play one on the Web. Moreover, the idea of human cloning is so repugnant that I’m not particularly interested in refuting it, any more than I want to think about refuting the idea of genocide or sex with furniture.
However, cloning is in the news, as it will be periodically for the next decade at least. We can’t ignore it. So I thought it would be useful — to myself, if no one else — to write a little “cheat sheet” listing the strongest arguments against cloning of any kind. No recourse to revelation necessary. Feel free to add your own in the comments box.
1. It will kill tiny human beings.
Whatever our differences about morality, virtually everyone agrees that it is wrong to deliberately end the life of an innocent human. Yet that’s what happens during embryo experimentation: scientists fiddle with the little one-celled creatures, and some of them die. They are indisputably human on a genetic level; they are individuals with a unique DNA structure; yet they enjoy virtually no protection under the law. (I’m avoiding the word “person” to describe embryos because a person is, technically, a being that thinks, wills, and acts, which embryos cannot do.) When you do something that deliberately ends a life, or something that you can be reasonably certain will end a certain number of lives out of a group, it’s called “killing.” Don’t shy away from using the word.
2. Humans should not be used as means to an end.
One would think we learned this lesson at great cost in the 20th century, but man must be constantly reminded. Every human being, because he posesses the dignity of an intelligent, created being, should be treated with respect. Doing medical experiments that kill tiny human beings in order to help other human beings is therefore wrong. When someone asks, “Do you really think these little cells are more important than my [brother, mother, daughter, etc.]?” the answer is, “No, they are equal. And just as we would not experiment on full-grown adults in order to help embryos, we shouldn’t experiment on embryos to help full-grown adults.” That’s true even if we are certain that we will gain positive results from embryonic experiments — and there’s no guarantee that those results will materialize.
3. We don’t know what we’re doing.
Did you know that biologists can’t even agree on how many genes there are? We are just beginning to research the human genome, as news stories used to say about genetic breakthroughs. Now they herald the potential cures that genetic experimentation can bring (and, it’s strongly implied, it almost certainly will bring them if people get over their petty qualms about how yucky cloning is.) Yet the more responsible news reports point out that any cures are years away, if not decades. We should remind people that all of this may be a dead end. We understand more than ever about cancer, for instance, but despite billions in research we have nothing like a cure for it.
4. We can’t produce clones anyway.
…at least not in the sense that people mean by “clone,” an exact replica of the original that will develop precisely as the original creature did. Maybe we can do it with bacteria — I’m not a biologist, either — but a complex vertebrate? Nope. Animal clones age more rapidly and have a higher rate of mutation and disease. Nobody knows why. Again, it’s not certain that we can overcome the obstacles. Ramesh Ponnuru has a much longer, better-written, and elegant argument against cloning on Tech Central Station, which I warmly commend to you.