- the “occurrent conception” - x is natural if and only if it exists in the world or universe.

- the “nonhuman conception” - x is natural if and only if x exists and is not the product of human activity (taking place at some specified level of technological development).

- the “theological conception” - x is natural if and only if it is what our creator intends or desires or permits.

- the “teleological conception” - x is natural if and only if it is the statistically normal development or result of something that is natural.

Here are some problems for these conceptions when we try to make the link between “not natural” and “immoral” or “impermissible”:

The occurent conception is either too permissive or too restrictive, perhaps depending on whether you are an A-theorist or a B-theorist about time. On the A-theory, nothing new was ever permitted. Obviously, that is too strict. Or on the B-theory, all actions that take place in the history of the universe are permitted. Obviously, that is too permissive.

The nonhuman conception either rules out too much as immoral, such as shelter, aspirin, and heart surgery, or risks setting the bar for non-natural technology arbitrarily (see Bostrom’ and Ord’s “Reversal Test” piece).

The theological conception faces interpretive questions (which god or gods? what exactly does this god or gods want?) and more fundamental challenges from atheists, Euthyphro, and panspermists, not to mention (at the political level), political liberals.

The teleological conception has to ultimately piggyback on one of the other conceptions, which is problematic enough.

Of course, this is a very quick and incomplete account, still, I don’t think “natural” can do the argumentative work many people expect it can. I’d be interested in hearing from those who disagree.

Many thanks for your helpful comments. On your two points:

(1) Perhaps I should have said “a more robust picture of morality” rather than “a full account of morality.” You are absolutely correct to say that we need not require a complete moral theory that can address all moral questions. However, we need to know more than “well, it is just immoral” and what the grounds are for this view. What makes the view immoral (e.g., immorality based upon what standard)? This seems sorely lacking.

(2) There are a handful of medical schools in the UK, including Newcastle’s medical school, that are permitted to perform cloning. This new legislation opens the doors to more schools engaging in related research. I agree this is the least important reason to support the new legislation. This is why I did not discuss it under either of the two main headings, but a brief comment in the conclusion to end the post.

Andrew:

This is absolutely correct: the fact that hybrid embryos of this sort are being created in a laboratory alone is supposed to lead necessarily to the “fact” that the creation of hybrid embryos are “immoral.” This seems a real jump lacking justification, at least as the argument stands. This is all I sought to highlight, as you capture better than I!

But I worry about your sweeping response, e.g. claiming that we could never legitimately raise moral objections “without a full account of morality”. The appropriate defence of hybrid embyonic research had better not carry over to, e.g., also defending Nazi-style experimentation. Our answer to that had better not wait on settling all questions of normative ethical theory!

Also, I guess the moral value of symbolically “carry[ing] on pioneering work at Newcastle’s medical school” is not entirely clear to me. Even if there’s something to be said for offering a “genuine endorsement” of medical research, it seems like this would be the least important reason to favour the policy, compared to the non-symbolic benefits. (Or am I missing something?)