I’d give us 50% odds of developing the technology capable of human genetic enhancement without excess embryos in the next decade. Editing looks like the most plausible candidate, though chromosome selection also looks pretty feasible.
I’ve given a lot of thought to the question of whether discarding embryos is acceptable. Maybe I’ll write a post about this at some point, but I’ll try to give a quick summary:
At the time of selection, human embryos have about 100 cells. They have no brain, no heart, and no organs. They don’t even have a nervous system. If they stopped development and never grew into humans, we would give them zero moral weight. Unless you believe that the soul enters the embryo during fertilization, the moral importance of an embryo is entirely down to its potential to develop into a human.
The potential of any given pairing of egg and sperm is almost unchanged after fertilization. A given pairing of sperm and egg will produce the same genome every time. I don’t see a clear line at fertilization regarding the potential of a particular sperm/egg coupling.
Roughly a third of regular non-IVF pregnancies end in miscarriage; usually before the mother even knows she’s pregnant. The rate of miscarriage approaches 100% towards a woman’s late 40s. If embryos are morally equivalent to babies, there is a huge ongoing preventable moral disaster going on during normal conception, to the point where one could make a case that unprotected sex between 40 and menopause is immoral.
Thanks for the response. I realize that this is a very belated reply, and that it would have done a lot more good prior to the release of your How-To-PSC essay. Nevertheless, I’ll respond to a few of your points.
For one thing, an embryo that was conceived from the gametes of two humans doesn’t “grow into a human” or “develop into a human”; it is a human. I’m not saying that this necessarily confers moral worth, but it does jog the question of which trait does, and you don’t provide a strong alternative.
In defense of the ZEF’s potentiality: before fertilization, an arbitrary pair of sperm and egg isn’t a coherent object any more than union of my left sock and the moon is a coherent object. In contrast, after fertilization, it’s the sperm and the egg that cease to be coherent objects. The egg releases chemical signals to reject additional sperm, the successful sperm’s cell membrane disintegrates, and the former contents of the gametes are bound together within one structure: the zygote.
I think that natural pregnancies are more nuanced than that, although I do agree that it involves an ongoing moral disaster to some extent. I don’t think it’s immoral for a woman to become pregnant despite the high miscarriage rate—just as I don’t believe it was immoral for a woman living 1,000 years ago to become pregnant, even though a third of her children who were born would die by the age of 5. Instead, I think that there’s an imperative on society to develop medical technology that prevents (pre)natal deaths.
Interesting viewpoint. I think your point about the morality of having children despite the high natural miscarriage rate is a good one.
My basic view is that human moral value develops throughout pregnancy (and indeed continues to develop after birth). I don’t think there’s a simple binary switch from “no value” to “value”. I’d treat it more like a gradual ramp-up beginning with brain development during pregnancy.
I’m curious how you feel about culturing of naive embryonic stem cells. It’s possible to culture cells from a very early embryo and maintain their epigenomic state. One might then perform some editing on each, then grow each into a colony of perhaps 100 cells before destructively sequencing some of the stem cells and then performing subsequent edits on the stem cells in which the edits successfully took place.
If done correctly, the process would result in an embryo with much better prospects for a healthy and happy life. One embryo goes in and one embryo goes out. But the sequencing in the interim steps would require the destruction of naive embryonic stem cells.
Would you consider such a process morally permissible?
I’d give us 50% odds of developing the technology capable of human genetic enhancement without excess embryos in the next decade. Editing looks like the most plausible candidate, though chromosome selection also looks pretty feasible.
I’ve given a lot of thought to the question of whether discarding embryos is acceptable. Maybe I’ll write a post about this at some point, but I’ll try to give a quick summary:
At the time of selection, human embryos have about 100 cells. They have no brain, no heart, and no organs. They don’t even have a nervous system. If they stopped development and never grew into humans, we would give them zero moral weight. Unless you believe that the soul enters the embryo during fertilization, the moral importance of an embryo is entirely down to its potential to develop into a human.
The potential of any given pairing of egg and sperm is almost unchanged after fertilization. A given pairing of sperm and egg will produce the same genome every time. I don’t see a clear line at fertilization regarding the potential of a particular sperm/egg coupling.
Roughly a third of regular non-IVF pregnancies end in miscarriage; usually before the mother even knows she’s pregnant. The rate of miscarriage approaches 100% towards a woman’s late 40s. If embryos are morally equivalent to babies, there is a huge ongoing preventable moral disaster going on during normal conception, to the point where one could make a case that unprotected sex between 40 and menopause is immoral.
Thanks for the response. I realize that this is a very belated reply, and that it would have done a lot more good prior to the release of your How-To-PSC essay. Nevertheless, I’ll respond to a few of your points.
For one thing, an embryo that was conceived from the gametes of two humans doesn’t “grow into a human” or “develop into a human”; it is a human. I’m not saying that this necessarily confers moral worth, but it does jog the question of which trait does, and you don’t provide a strong alternative.
In defense of the ZEF’s potentiality: before fertilization, an arbitrary pair of sperm and egg isn’t a coherent object any more than union of my left sock and the moon is a coherent object. In contrast, after fertilization, it’s the sperm and the egg that cease to be coherent objects. The egg releases chemical signals to reject additional sperm, the successful sperm’s cell membrane disintegrates, and the former contents of the gametes are bound together within one structure: the zygote.
I think that natural pregnancies are more nuanced than that, although I do agree that it involves an ongoing moral disaster to some extent. I don’t think it’s immoral for a woman to become pregnant despite the high miscarriage rate—just as I don’t believe it was immoral for a woman living 1,000 years ago to become pregnant, even though a third of her children who were born would die by the age of 5. Instead, I think that there’s an imperative on society to develop medical technology that prevents (pre)natal deaths.
Interesting viewpoint. I think your point about the morality of having children despite the high natural miscarriage rate is a good one.
My basic view is that human moral value develops throughout pregnancy (and indeed continues to develop after birth). I don’t think there’s a simple binary switch from “no value” to “value”. I’d treat it more like a gradual ramp-up beginning with brain development during pregnancy.
I’m curious how you feel about culturing of naive embryonic stem cells. It’s possible to culture cells from a very early embryo and maintain their epigenomic state. One might then perform some editing on each, then grow each into a colony of perhaps 100 cells before destructively sequencing some of the stem cells and then performing subsequent edits on the stem cells in which the edits successfully took place.
If done correctly, the process would result in an embryo with much better prospects for a healthy and happy life. One embryo goes in and one embryo goes out. But the sequencing in the interim steps would require the destruction of naive embryonic stem cells.
Would you consider such a process morally permissible?