The tricky part is deciding what is meant by 'others'. Normally, we
mean 'other human beings', but of course there is already controversy
about this point in the debate over abortion.
In deciding when and how it is ethical to clone a human or part of a
human, I think it is also important to answer this same question. When
do we say a living thing is a human like us, and therefore deserves to
be treated like other humans? I would say that an unborn baby of 6 or 7
months is a feeling, thinking being that has a right to life very close
to that of a baby that has been born. I would also say that a newly
fertilized embryo of just a few cells is very different from a baby
near birth and does not have an equivalent ethical claim to life.
So, in general, I would say that cloning might be ethical as long as it
does not unfairly affect the life of a being that I would consider to
be a human being. This is a pretty general rule, and one would have to
define it much more carefully when applying it to specific situations.
For example, therapeutic cloning using embryonic stem cells might be
ethical if only component 'parts' were produced. But if you used
cloning to create a full-developed human being, I don't think it would
be ethical to use that human being for 'parts'.
Then there is the separate question, is it ethical to clone yourself,
not for parts, but for reproduction? I'm not sure what the answer is to
this question. If we apply a principle of fairness, such as the golden
rule, I would ask myself, would I mind if I was born as a clone of
someone else? I suppose that would depend on who that person was, how
they treated me, and what the rest of the world was like that I was
being born into. Right now, I suspect that it would be better to not be
a clone, but to be a combination of two people, a mother and a father.
But for me, that is more like a personal opinion, and I don't think I
would assert it as a general ethical principle that is true for all
places and times.