Sometimes there is a cause, and sometimes a reason.
Thirst causes to drink, one doesn't search to determine if her, drinking is a good or bad thing to do. Causality heads someone to act in a special way and not another one. Reason heads to determine what is good/bad, right/wrong.
Coming back to the modified embryo, I think we are still at the "reason" stage. It is stilll possible to study the case, to go backwards, or not. However, a first foot ahead in the GM world might CAUSE a vicious circle, and from causes to consequences, and to causes to consequences, who knows where we will stop? There will possibly be a REASON to go back to our previous ethical believes, but CAUSALITY would weight much more.
Let's go back to this one, we all came upon it at some point, heard it somewhere somehow : What is good in life? Certains things are desirable as means and others in themselves : we do not desire stress but stress could lead to fulfillment. Being genetically modified :
" If I could choose that my children would not suffer from Schizophrenia as I do and maybe never have to worry about Cancer as well then I see it as an advance and preventer of misery." (Jericho)
Well, it is here a hard topic, Schizophrenia, cancer...
Is it really desirable to look back on our life and see how unatural human beings we are, how not human...? We are somewhat already there with all the medications we have, they can make us loose our identity, make us feel lost, make us feel like we have been modified not at birth but during our lifetime ...
"Another point: I've struggled with severe anxiety and depression all my life. I've been taking medication for it since I was 16, to the point where I really don't know what my "true" personality is and what the medicine is doing. How is that better than being modified at birth so I didn't have those problems in the first place? At least I would have be able to develop some sense of self. And I wouldn't live or die (literally) on whether I can afford medication."(Jessica)
On another hand, is it really inhuman, not human, to go on with science, since science, reason is a human characteristic?
Could GM be seen as a mean to "fulfillment" for some people, a mean to become a "dominant", have a dominant life? Feeling modified but being at the top.